Work Package 3 D.3.1

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Project contract no. 037038



SOCOPSE

Source Control of Priority Substances in Europe



Specific Targeted Research Project



Work Package 3


D.3.1



An Inventory and Assessment of Options for Reducing Emissions:

Hexachlorobenzene (HCB)


Second Draft



Due date of delivery: June 2008

Actual submission date: October 2008




Start date of project: 1
st

November 2006




Duration: 36 months



Lead partner for this deliverable: INERIS




Project co
-
funded by the European Commission within the Sixth Framewor
k Programme (2002
-
2006)

Dissemination Level

PU

Public

X

PP

Restricted to other programme participants (including the Commission Services)


RE

Restricted to a group specified by the consortium (including the Commission Services)


CO

Confidential, only
for members of the consortium (including the Commission Services)




2


An Inventory and Assessment of
Options for Reducing Emissions:

Hexachlorobenzene (HCB)


_____________


Draft 2




This report was prepared within Work Package 3 of project SOCOPSE.



Au
thor:

Aurélien Genty (1)



Contributors:

Jean
-
Marc Brignon (1), Lourens Feenstra (2), Willy van
Tongeren (2), Ralph Lindeboom (3), Frank I.H.M. Oesterholt
(3), Arnt Vlaardingerboek (3), Janusz Krupanek (4), Urszula
Zielonka (4), Susanne Ullrich (5)



(1)

I
nstitut National de l´Environment Industriel et des Risques (INERIS)

(2)

Nederlands Organisatie Voor Toegepast Natuurwetenschappelijk Onderzoek (TNO)

(3)

KIWA WATER RESEARCH B.V. (Kiwa WR)

(4)

Institut Ekol
ogii Terenów Uprzemysłowionych (IETU/Envitech)

(5)

University of Southampton, School of Civil Engineering & the Environment (SOTON)





Options for reducing emissions: HCB


3

Contents

Contents

................................
................................
................................
................................
......

3

1.

Executive summary

................................
................................
................................
............

4

2.

Introduction

................................
................................
................................
........................

8

3.

General information

................................
................................
................................
...........

9

3.1

Presentation of the substance

................................
................................
........................

9

3.2

Classification and labelling

................................
................................
...........................

9

3.3

Regu
lations and controls for the substance

................................
................................
.

10

4.

Production, uses and emissions

................................
................................
........................

12

4.1

Production and uses

................................
................................
................................
....

12

a)

Production

................................
................................
................................
...................

12

b
)

Uses

................................
................................
................................
.............................

13

4.2

Emissions

................................
................................
................................
....................

13

a)

Environmental fate

................................
................................
................................
......

13

b)

Emission sources

................................
................................
................................
.........

14

5.

Options for reducing emissions: detailed infor
mation

................................
.....................

17

5.1

Source control options

................................
................................
................................

17

a)

Process
-
oriented options

................................
................................
.............................

17

b)

User
-
oriented options: Pesticide application
................................
...............................

23

c)

Alternatives options

................................
................................
................................
....

26

5.2

End
-
of
-
pipe options for the substance

................................
................................
........

26

a)

Industrial end
-
of
-
pipe techniques
................................
................................
................

27

b)

Sedimentation

................................
................................
................................
.............

28

c)

Environmental buffers

................................
................................
................................

30

d)

Soil remediation

................................
................................
................................
..........

31

e)

Sector specific techniques

................................
................................
...........................

32

6.

Options for reducing emissions: synthesis

................................
................................
.......

34

7.

Conclusion

................................
................................
................................
........................

39

8.

Acknowledgements

................................
................................
................................
..........

40

9.

References

................................
................................
................................
........................

41



Options for reducing emissions: HCB


4

1.

Executive summary

Hexachlorobenzene (HCB), recognised as a POP (persistent organic

pollutant), is currently an
unintentional by
-
product of several industrial sectors where both chlorine and carbon are
present. In Europe for many years, there is neither use of HCB, nor intentional production. It
was formerly used for a variety of applica
tions, but the main use by far was as a fungicide.
The concentration in the environment is mainly due to historical pollution and accumulation.
Current European emissions of HCB are quite low but still significant. Releases to water
come mainly from air de
position, the remaining from industrials, pesticide application (past or
present) and waste treatment. Options for reducing emissions are about source control options
in industry and agriculture and end
-
of
-
pipe options for waste treatment. These abatement
measures are presented below.

Table
1

shows possible emission abatement measures related to emission sources.

Table
1

: Emission sources and possible emission abatement measures


Sources

Secondary
aluminium
processing

Chemical
manufacturin
g

Combustion

Pesticide
application

Waste
treatment

Measures

Source control

X





Choice of oil
-

and
chlorine
-
free feeds

X


X



Pre
-
treatment of raw
material

X

X




Combustion control

X


X



Limi
tation of demagging
impacts

X





Closure of small
-
scale
facilities

X

X




Implementing green
chemistry


X




Careful operations and
rigorous maintenance

X

X

X



Process modification


X




Purification of products
by distillation


X




Recyclin
g unintentional
HCB generation


X




Reducing application
rate/frequency




X


Shifting application date




X


Controlling sprayers




X


Conservation tillage




X


Ground cover




X


End
-
of
-
pipe






Vegetated buffer strips




X


Construc
ted wetlands




X


Industrial end
-
of
-
pipe
techniques

X

X

X


X

Note: X = available measure; O = emerging measure


Options for reducing emissions: HCB


5

Table
2

: Assessment of source abatement measures


Assessment

Remarks

Measure /
source

Technical
feasibility

Perform
ances

Costs

State of the
art


Source
control






Choice of oil
-

and chlorine
-
free feeds


Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

medium

Cnd.:


Lim.:

medium

Imp.:

Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

Numerous

Pre
-
treatment of
feed material

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

wide

Cnd.:


Lim.:


Imp.:

Eff.:


Oth.:


En.:


CE:

Yes

W:


IC:


OC:



St:

Yes

App:

Numerous

Combustion
control


Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

wide

Cnd.:


Lim.:


Eff.:


Oth.:

yes

En.:


CE:


W:


IC:


OC:



St:

Yes

App:

Numerous

Limitation of
demagging
impacts

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

wide

Cnd.:


Lim.:


Eff.:


Oth.:

Yes

En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Closure of
small
-
scale
facilities


Total score:


Total score:


To
tal score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Implementing
green chemistry

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Rem
ark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Careful
operations and
rigorous
maintenance


Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:

none

OC:

low


St:

Yes

App:

numerous

Process
modification

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE
:


W:


IC:


OC:



St:

Yes

App:

numerous

Purification of
Total score:


Total score:


Total score:


Total score:


-

Remark 1

Options for reducing emissions: HCB


6

products by
distillation


Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App
:

numerous

-

Remark 2

Recycling
unintentional
HCB generation

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Reducing
applicatio
n
rate/frequency



Total score:

+

Total score:


Total score:

++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

medium

Imp.:
medium

Eff.:

variable

Oth.:

Yes

En.:

No

CE:

No

W:

No

IC:

none

OC:

low


St:

Yes

App:

numerous

Shi
fting
application date

Total score:

+

Total score:


Total score:

++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:
medium

Imp.:
medium


Eff.:

variable

Oth.:

Yes

En.:

No

CE:

No

W:

No

IC:

none

OC:

low


St:

Yes

App:

numerous

Controlling
sprayers


Total score:

++

Total score:


Total score:

++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

low

Imp.:
low

Eff.:

variable

Oth.:

Yes

En.:

No

CE:

No

W:

No

IC:

none

OC:

low


St:

Yes

App:

numerous

Cons
ervation
tillage

Total score:

0

Total score:


Total score:
++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

high

Imp.:
medium

Eff.:

?

Oth.:

Yes

En.:

No

CE:

No

W:

No

IC:

low

OC:

low


St:

Yes

App:

numerous

Ground cover

Tot
al score:

++

Total score:


Total score:

++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

low

Imp.:
medium

Eff.:

?

Oth.:

Yes

En.:

medium

CE:

No

W:

No

IC:

none

OC:

medium


St:

Yes

App:

numerous

End
-
of
-
pipe






Grass stri
pes

Total score: ++

Total score:

Total score: +

Total score: ++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

low

Imp.:

Eff.:

?

Oth.:

many

En.:

low

CE:

No

W:

No

IC:

low

OC:

medium


St:

Yes

App:

numerous

Hedges

Total score: ++

Total sco
re:

Total score:
0

Total score: +

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

low

Imp.:

Eff.:


Oth.:

many

En.:

low

CE:

No

W:

No

IC:

medium

OC:

medium


St:

Yes

App:

numerous

Riparian zones

Total score: ++

Total score:

Total score: +

T
otal score: +

-

Remark 1

Options for reducing emissions: HCB


7

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

medium

Imp.:

Eff.:


Oth.:

many

En.:

No

CE:

No

W:

No

IC:

medium

OC:

low


St:

Yes

App:

numerous

-

Remark 2

Constructed
wetlands

Total score:

+

Total score:


Total score:

-

Total score:

0

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:
wide

Cmp.:

low

Lim.:

high

Imp.:

Eff.:


Oth.:

many

En.:

No

CE:

No

W:

No

IC:

high

OC:

medium


St:


App:

some

Activated
carbon
adsorption


Total score:

+

Total score:


Total score:
--

Total score:

++

-

Remark 1

-

Re
mark 2

Pol.:

point

Rge:

wide

Cnd.:

medium

Lim.:

medium

Eff.:


Oth.:

many

En.:

medium

CE:

Yes

W:

Yes

IC:

high

OC:

high


St:

Yes

App:

numerous

Gas filtration

Total score:

Total score:

Total score:

Total score:

-

Remark 1

-

Remark 2

Pol.:

point

Rge:

wid
e

Cnd.:


Lim.:


Eff.:


Oth.:

many

En.:


CE:

Yes

W:

Yes

IC:

high

OC:

medium


St:

Yes

App:

numerous

Sedimentation
of solids

Total score: +

Total score:
0

Total score:

Total score: ++

-

Remark 1

-

Remark 2

Pol.:

point

Rge:
wide

Cmp.:

low

Lim.:

medium

Imp
.:

medium

Eff.:

medium

Oth.:

many

En.:


CE:

medium

W:

high

IC:


OC:



St:

Yes

App:

numerous

Afterburners

Total score:

Total score:

Total score:

Total score:

-

Remark 1

-

Remark 2

Pol.:

point

Rge:

wide

Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:


App:


Open burning of
waste

Total score:

+

Total score:


Total score:


Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

medium

Lim.:

low

Eff.:


Oth.:

many

En.:


CE:


W:


IC:


OC:



St:

Yes

App:

Numerous

Soil
dechlorination

Total score:


Total score:


Total score:


Total score:

--

-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

narrow

Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

emerging

App:

None

Note:
Pol.

= Type of pollution;
Rge

= Range of concentration;
Cnd.

= Needed conditions;
Lim.

= Limits and
restrictions;
Cmp.

= Complexity of implementation;
Imp.

= Impact on the process, on the factory;
Eff.

=
Efficiency of emission reduction;
Oth.

= Removal of other pollutants;
En.

= Consumption of energy;
CE

= Cros
s
effects;
W

= Production of waste;
IC

= Investment costs;
OC

= Operational costs;
St

= Status of the technique
(BAT, existing, emerging);
App.

= Number of applications.

Options for reducing emissions: HCB


8

2.

Introduction


The overall objective of this document is the inventory and assessment
of technical options
for reducing the water emissions of hexachlorobenzene (HCB) in Europe. Options include
end
-
of
-
pipe techniques (e.g. wastewater treatment) and process
-
integrated technical options
(e.g. substitution or closed
-
circuit operation). The doc
ument aims to identify main uses and
emission sources for HCB

and to assess in terms of costs, effectiveness, and feasibility the
technical means to abate emissions in water. It has been developed to give stakeholders a
background material and an overview
of possible reduction options at the European scale in
the perspective of future emission reduction strategies to be developed.

The document is a result of project SOCOPSE, which is a European research project funded
by the EU 6
th

framework program for res
earch. The goal of this project is to support the
implementation process of the Water Framework Directive by providing guidelines and
decision support system for the management of priority substances.

The scope of the document is the pollution in continent
al waters. It covers the most important
sectors responsible for direct and indirect emissions, discharges and losses to aquatic
environment in Europe. Therefore, the control of pollution to air and land is out of the scope,
and polluted air and land will b
e considered only as potential sources of pollution to water.


The document was prepared as follows. The identification of main uses and emission sources
for HCB

was achieved in a separate project task based on literature review and expert
judgement. Here
are reported the main conclusions.

As concerns the assessment of technical options, a literature review was conducted on both
existing and emerging options to abate emissions to water. At the same time a survey was
carried out with the main contributors to

emissions to evaluate the options applied or
considered in practice. Both information sources were compared and compiled in a first draft
document which then was sent to stakeholders and debated during a one
-
day technical
workshop. A second draft document

included the workshop remarks. The final document
takes into account the results of case studies conducted at the later stages of project
SOCOPSE.

Survey questionnaire, list of contacted organisations and list of participants to workshop are
attached in a
ppendices.


The document plan is as follows. Section 3 gives general information on HCB. Section 4
presents results on main uses and emissions of the substance. Section 5 reviews the technical
options to reduce emissions, with a synthesis in Section 6. Sec
tion 7 concludes the document,
with acknowledgements in Section 8 and references in Section 9.


Options for reducing emissions: HCB


9

3.

General information

3.1

Presentation of the substance

Hexachlorobenzene (HCB) is currently an unintentional by
-
product of several industrial
sectors where both chl
orine and carbon are present
(Royal Haskoning, 2003)
. This substance
is toxic, persistent, and liable to bio
-
accumulate, and so is recognised as a POP (persistent
organic pollutant).

HCB is from a chemical point of view a chlorinated aromatic hydrocarbon with the followin
g
formula: C
6
Cl
6
. Under normal conditions its physical state is white crystals
(Euro Chlor,
2002)
. HCB is little soluble in water (water solubility at 25 °C: 5

µg/l) but in lipid solution
and is volatile (vapour pressure: 2.3

10
-
3

Pa)
(Tissier

et al.
, 2005)
.
Table
3

shows its chemical
identity.


Table
3
: Identity of HCB

Substance

IUPAC name

Formula

CAS #

EINECS #

St
ructure

HCB

Hexachlorobenzene

C
6
Cl
6

118
-
74
-
1

204
-
273
-
9




3.2

Classification and labelling

European chemical Substances Information System
(European Chemicals Bureau, 2007)

gives the classification for HCB, according to the criteria set up in the amended Annex VI of
Directive 67/548/EEC (last amendment: Directive 2001/59/EC).
Table
4

shows this
classification.


Table
4
: Classification for HCB

Type of risk and advice

Classification

Risk based on toxicological properties

T; R48/25

Risk based on effects on human health

Carcinoge
nic category 2; R45

Risk based on environmental effects

N; R50
-
53

Safety advice

S45
-
53
-
60
-
61

All risks

Carc. Cat. 2; R45


T; 刴㠯㈵o


主⁒㔰
-




Table
5

gives the meaning of the indications of danger, the C
MR (carcinogenic, mutagenic
and toxic to reproduction) classification, the risk phrases (R
-
phrases), and the safety phrases
(S
-
phrases) for HCB.

Options for reducing emissions: HCB


10


Table
5
: Carcinogenic, Mutagenic and Reprotoxic categories for HCB

Classification/Label
ling

Meaning

T;


Toxic

N;


Dangerous for the environment

Carcinogenic category 2

Substances which should be regarded as if they are carcinogenic to
man. There is sufficient evidence to provide a strong presumption
that h
uman exposure to a substance may result in the development
of cancer, generally on the basis of:

appropriate long
-
term animal studies,

other relevant information.

R45

May cause cancer

R48/25

Danger of serious damage to health by prolonged exposure if
swa
llowed

R50

Very toxic to aquatic organisms

R53

May cause long
-
term adverse effects in the aquatic environment

S45

In case of accident or if you feel unwell, seek medical advice
immediately (show the label where possible)

S53

Avoid exposure


Obtain spe
cial instructions before use

S60

This material and its container must be disposed of as hazardous
waste

S61

Avoid release to the environment. Refer to special instructions /
safety data sheet



3.3

Regulations and controls for the substance

HCB is regulated

by a number of European rules. The Water Framework Directive
(2000/60/EC), so
-
called WFD, including the final Decision 2455/2001/EC identifies HCB as
a priority hazardous substance (annex X of WFD), which means this substance has been
shown to be of very
high concern for European waters. As a priority hazardous substance,
HCB is subject to controls for the cessation or phasing
-
out of discharges, emissions and losses
(article 16.6 of WFD).

In its communication
COM(2006) 397 final,
the Commission has recentl
y made a formal
proposal for directive which fixes some environmental quality standards for European waters
.
Those

for HCB are shown in
Table
6
.

At this point, either the European Parliament or the
Council has no
t adopted the proposal for directive.


Options for reducing emissions: HCB


11

Table
6
: Environmental quality standards in surface waters for HCB

AA
-
EQS

MAC
-
EQS

Inland surface
waters

Other surface
waters

Inland surface
waters

Other surface
waters

0.01 μg/l

0.01 μg/l

0.05 μg/l

0.05 μg/l

Note:
AA
-
EQS stands for annual average
-

environmental quality standards

and MAC
-

EQS for
maximum allowable concentration
-

environmental quality standards
.



In addition, since 1981, Directive 79/117/EEC prohibits
the placing on the market and use of
HCB as a plant protection product in the European Union. In 1992, the importation and
exportation of HCB was severely restricted by Regulation 2455/92, especially with the
implementation of the Prior Informed Consent (P
IC) procedure. In 2003, Regulation 304/2003
implementing the Rotterdam Convention (1998) on the PIC procedure prohibited the HCB
exports to third countries.

Advanced legislation on HCB was achieved, within the framework of the United Nations
Environment Pr
ogramme (UNEP), by the Aarhus Protocol (1998) to the 1979 Convention on
long
-
range transboundary air pollution on POPs and the Stockholm Convention (2001) on
POPs. These international agreements establish a global regime for controlling POPs,
including HCB
, and aim at eliminating or reducing their use. They were implemented at the
European level in 2004 by Regulation 850/2004, which prohibited, among others, the
production, placing on the market and use of HCB.

For unintentional HCB emissions, the Stockholm

Convention sets out a set of measures with
the goal of their continuing minimisation and ultimate elimination. In this view, Regulation
850/2004 obliges Member States to report all HCB emissions in release inventories, which are
aggregated in European dat
abase EPER, and to develop action plans to reach the elimination
of the total releases. Moreover the IPPC Directive (Directive 96/61/EC) is applying more
specifically with respect to HCB emissions to the following sectors: combustion installations
(categor
y 1.1); production and processing of metals (category 2); chemical industry (category
4, and especially 4.1); and waste management (category 5, and especially 5.1). And there are
Best Available Technique (BAT) defined specifically for HCB in the following
BREF
documents under the IPPC Directive: common wastewater treatment; textiles industry; and
non
-
ferrous metal industry.

In conclusion, HCB is totally banned (except for research) in Europe as a substance but can
still be occurring as unintentional release

or unintentional trace contaminant in products.


Options for reducing emissions: HCB


12

4.

Production, uses and emissions

4.1

Production and uses

a)

Production

The common route for industrial HCB production is the direct chlorination of benzene at 150
-
200°C over a ferric chloride catalyst
(UNEP, 2007a)
. Other routes include the distillation of
residues from perchloroethylene production and the
refluxing of hexachlorocyclohexane
isomers with sulphuryl chloride or chlorosulphonic acid in the presence of a ferric chloride or
aluminium catalyst
(IPCS, 1997)
. However, there is no intentional HCB production in Europe
anymore.

HCB is known to be a by
-
product of the manufacture of chlorinated hydrocarbons/solvents
such as carbon tetrachloride and perchl
oroethylene and to some extent trichloroethylene,
tetrachloromethane, vinylchloride, or pentachlorobenzene
(Ritter

et al.
, 1995; Pacyna

et al.
,
2003; UNEP, 2007a)
. The current manufacture of chlorinated solvents generates only trace
quantities of HCB, estimated to below 20

ppb
(Government of Canada, 2003)

and even as
1

ppb
(Bailey, 2001)
. But it might be in some cases a potential for HCB
-
contaminated wastes.
And UNEP

assumed that it could still be occurring some old waste stockpiles from the
historical chlorinated solvent production with significant amounts of HCB.

As well, Ritter
et al.

(19
95)

noted that HCB was a known impurity in several pesticide
formulations, including pentachlorophenol and dicloran. Bailey
(2001)

estimated the amounts
of HCB impurity contained in

the most concerned pesticides (
Table
7
). However almost all
these pesticides (except DCPA, picloram, and chlorothalonil) have been already banned in the
EU.


Table
7
: HCB contamination of
pesticides

Pesticides

Contamination (in ppm)

Dimethyl tetrachloroterephthalate (DCPA
or Chlorthal
-
dimethyl)

1000

Pentachloronitrobenzene (PCNB)

500
-
1000

Technical Hexachlorocyclohexane (HCH)

100

Pentachlorophenol

50
-
100

Lindane

50

Picloram

50

Chloro
thalonil

40
-
100

Simazine

1

Atrazine

1

Sources: Bailey
(2001)



Lastly, HCB like dioxins and furans may be unintentionally produced in combustion
processes in case of inappropriate

operations or inadequate combustion temperatures
(UNEP,
2007b)
.


Options for reducing emissions: HCB


13

b)

Uses

HCB has not been u
sed anymore in Europe for many years. It was formerly used for a variety
of applications, but the main use by far was as a fungicide (seed treatment, control of bunt
diseases). Other past uses include
(Öberg, 1996; IPCS, 1997; Pacyna

et al.
, 2003; Royal
Haskoning, 2003; UNEP, 2005
, 2007a)
:

-

wood preservation,

-

paper impregnation,

-

secondary aluminium processing (fluxing and degassing),

-

formulation for ammunition and fireworks,

-

peptising agent for synthetic rubber (nitroso and styrene rubber for tyres),

-

plasticiser in PVC,

-

porosity
-
co
ntrol agent in the manufacture of graphite electrodes,

-

chemical intermediate in the manufacture of organic compounds (pentachlorophenol,
aromatic fluorocarbons) and certain dyestuffs.


4.2

Emissions

a)

Environmental fate

Due to high persistence (air: half
-
life of

2.6

years; land/water: half
-
lives of 2.6
-
5.7 and 10.6
-
22.9

years with aerobic and anaerobic biodegradation, respectively) and semi
-
volatility, HCB

is
found everywhere (air, water, and lands).
.

As an order of magnitude, usual HCB
concentrations are below 1

ng/l in water and 1

ng/m
3

in air
(IPCS, 1997)
.
Although the global
volume of soil is considerably less than the volume of air, soil will contain a much greater
mass of HCB th
an air. Significant amounts of HCB can also be found in water, rivers, lakes
and, in particular, seas since, although the concentrations of HCB in seawater are low, the
volume of the oceans is very large, and therefore, oceans may be important sinks for HC
B.
Finally, t
he adsorption of HCB onto particulate matter and sediment is an important
mechanism for its removal from the water column. Consequently, the sediment component of
aquatic ecosystems can be

a significant sink of HCB

(Barber et al., 2005)
.

Figure
1

gives the theoretical HCB fate according to the Mackay’s level I model
1

(Tissier

et
al.
, 2005)
, which shows that HCB should be mainly in the soil compartment.


Sediments
2,0%
Water
0,2%
Soil
88,2%
Air
9,6%

Figure
1
: HCB fate modelling





1

The level I model assumes a closed, stationary system at equilibrium. In particular, there are neither losses nor
degradations.

Options for reducing emissions: HCB


14

Although HCB is very persistent, it does degrade at a slow rate

in all environmental
compartments.
It is suggested from different
sources (
mass balance calculation,

existing
multimedia fate models and reported

degradation rates
)

that the greatest losses of

HCB in the
environment may occur from sediment and

soil, with
losses in water of less importance and
losses

in air insignificant. Levels of HCB in air and water will

probably continue to decrease
at a slow rate, whereas

levels in soil will continue to decrease significantly,

either by
degradation or re
-
volatilisation

(Barber et al., 2005)
.

b)

Emission sources

Although HCB production has ceased in most countries, it is still being generated
inadvertently as a by
-
product and/or impurity in several chemical processes, such as the
manufacture of chlorinated solvents, chlorinated aromatics and pesticides (Jacoff et al., 1986),
and is also released to the environment by incomplete combustion, and releases from old
dumpsites

(Barber et al., 2005)
. However, current emissions are only a
fraction of those that
occurred at the peak of deliberate HCB production, namely to
about

70

95% lower than
emissions in 1970.


Figure
2

shows the modelling of HCB air emissions at the European level
(EMEP, 2007b)
. In
the EU, it appears that these emissions should come mainly from Spain. Other significant
emissions co
me from the UK and Italy and to some extent Portugal, Denmark, the
Netherlands, and Lithuania. But these data should be considered with caution given that they
are based on the official notifications of emissions by Member States, which, likely due to
unde
restimation, are generally lower than available unofficial data
(Gusev

et al.
, 2007)
.



Sources: EMEP
(2007b)

Figure
2
: Spatial distribution of HCB emissions for 2005 (g/km
2
/y)



Options for reducing emissions: HCB


15

Table
8

presents the main emission sources of HCB to air, land, and water. Here are given
three estimations of the contribution of HCB sources to the air emissions, and one estimation
(expert values) for the sour
ce contribution to land and water emissions. We have to note that
the assessment of atmospheric emissions is more advanced and accurate than for the two other
compartments.


Table
8
: HCB emissions to air, land, and water

Media

Source
s

Contribution (%)

SOCOPSE
1

Berdowski
2

Gusev
3

Air

Manufacturing / industrial use of
products, including:

50

59

45


-

chemical manufacturing

-

23

7


-

metal manufacturing

-

8

22


-

use of chlorine solvents

-

11

-


-

other industries

-

17

16


Pestic
ide application

35

23

9


Waste incineration

5

1

7


Public power and heating /
Combustion of fossil fuels

Low

17

10


Residential, road transport, other
mobile sources, and machinery

Low

0

17


Wood preservation

Low

0

0


Other

0

0

12

Land

Atmospheric de
position

50

-

-


Pesticide application

40

-

-


Land
-
filling of wastes

10

-

-

Water

Atmospheric deposition

65

-

-


Pesticide application

15

-

-


Manufacturing / industrial use of
products

10

-

-


Waste treatment plants

5

-

-


Combustion of fossil fue
ls,
including cooling tower waters

Low

-

-

1

SOCOPSE estimates are based on the work of SOCOPSE Work Package 2; reference year: 2000;
geographic area: all Europe;

2

Berdowski
(1997)
; reference year: 1990; geographic are
a: 15 European countries;

3

Gusev
(2007)
; reference year: 2005; geographic area: 21 European coun
tries.


In EU
-
27, the 2005 HCB emissions to air are estimated at 10.2

t/y
(EMEP, 2007a)
. For the
whole Europe, 2000 HC
B emissions to land and water are estimated by the authors at 25 and
7

t/y, respectively (EU
-
27: 10.3 and 3.7

t/y, respectively); but these latter figures should be
considered with caution due to lack of data. In comparison, the past emissions might have
b
een ten times as much as current emissions when the peak HCB production in late seventies
was about 8,000 tons per year in Europe
(Rippen and Frank, 1986, cited in UNEP, 2006)
. As
a result, the concentration in the environment is mainly due

to historical pollution and
accumulation.

Options for reducing emissions: HCB


16

As shown in
Table
8
, HCB releases to water in Europe may come mainly from air deposition
(two thirds); for one third, they result from manufacturing / industrial use of
products,
pesticide application (past or present) and waste treatment.

As regards atmospheric emissions, the three estimations


SOCOPSE, Berdowski
(1997)
, and
Gusev
(2007)



are not directly comparable since the scopes are different (geographical,
reference year). But they can be used to rank the emission sources.
In all cases, it appears that
the main
emission
sources
to

air

are industrial processes/uses (including manufacture of
chemicals, metal processing, and use of chlorine solvents), pesticide application, combustion,
and to some extent waste incin
eration; residential
and road transport
emissions might also be
a significant source.

Comparing water emission sources with atmosphere
ones pesticide
applications are predominan
t in water whereas manufacturing
processes are in the
atmosphere.
However, t
aking into account atmospheric deposition in water,
the

main

source
s

of water emissions becomes manufacturing processing (about 42%
contribution)

then
pesticide applications

(about

38% contribution) and far behind
waste
treatments
plants (about
8% contribution)
and combustion of fossil fuel

(low contribution)
.

These results should be moderated

yet.

T
he
CITEPA’s annual report on
french
HCB
air
emissions
(based on
the European Environ
ment Agency
CORINAIR
system of the)

highlig
h
ts
important evolutions.

In 1990, the main emission source
in France
is the non
-
ferric metal
industry and more particularly the
secundary aluminium processing. Emissions from this
sector has then
substantially de
creased since 1993 to become nil since 1999.
In 2006,
principal sectors
are heavy goods vehicles (21%),
energy transformation sector (including
among others combustion processes: 19%),
catalysed
diesel oil engine vehicles (
25.7%), non
-
catalysed diesel oil
engine vehicles

(10.1%), waste treatment (
and more particularly
wastewater sludge incineration
11%).

As a result,
the
road transport
contributes
to about
one
half to air emissions
and energy transformation
to one fifth
. Given that the vehicle fleet
,

includ
ing catalysed vehicles,
increases

emissions from this sectors should increase too
(CITAPA, 2008)
.


Therefore the technical options further discussed in the following will focus on sources from
manufacturing / industrial use of products, pesticide applications for
seemin
gly

historical
HCB
releases and on waste t
reatment
s
, combustio
n
process
and road transport
s

to take current
releases into account.

Options for reducing emissions: HCB


17

5.

Options for reducing emissions: detailed
information


5.1

Source control options

a)

Process
-
oriented options


Here are described the measures for limiting the emissions of
HCB by production processes
(metal and chemical manufacturing) and combustion. The measures are based in particular on
the work of UNEP
(2006)
.

(i)

Secondary aluminium processing



Description of the process

Secondary aluminium processing consists in metal recovery by pre
-
treating, smelting, and
refining used aluminium products or process waste
(UNEP, 2006)
. Main steps include pre
-
treatment, charging, melting, fluxing, demagging, degassing, alloying, skimming, and pouring
(USEPA, 1995)
.

During the process, HCB can be formed due to incomplete combustion, contaminated feed,
and chemical additions for demagging. As secondary aluminium processing is essentially a
dry process, emissions are mostly to air (wastewater

emissions can occur with wet systems for
air pollution control).

Smelting is conducted using reverberatory, rotary, or induction furnaces. Except induction
which operates with electricity, the other furnace types need fuel combustion as heat source.
Poor
combustion of fuels or the organic content of the feed material can result in the emission
of organic materials, including HCB.

Feed material consists of process scrap, used beverage cans, foils, extrusions, commercial
scraps, turnings, old rolled, cast me
tal, and also skimmings and salt slags from the secondary
smelting process
(European IPPC Bureau, 2001)
. In particular, scrap may be contaminated
with oil, plastics or coatings, which are to be removed (pre
-
treatment) for reducing emissions.

Demagging consis
ts in removing magnesium from the melt by the use of chemicals. In the
past, liquid chlorine was used and injected under pressure with carbon lances directly into the
molten aluminium to react with magnesium, which resulted in high chlorine (chloride
compo
unds) emissions
(USEPA, 1995)
. More recent operations reducing chlorine emissions
involve a different procedure with injection of chlorine gas mixtures (e.g. chlorine, anhydrous
aluminium chloride, or chlorin
ated organics) or aluminium fluoride (e.g. sodium aluminium
fluoride or potassium aluminium fluoride)
(USEPA, 1995; European IPPC Bureau, 2001)
.



Mitigation measures

Several mitigation measures can be taken to limit HCB emissions:

-

Choice of oil
-

and c
hlorine
-
free feeds,

-

Pre
-
treatment of the feed material,

-

Combustion control,

Options for reducing emissions: HCB


18

-

Limitation of damaging impacts,

-

Closure/ limitation of impacts of small
-
scale aluminium recovery,

-

Cleaning emissions (end
-
of
-
pipe techniques)


The end
-
of
-
pipe solutions are discuss
ed in the end
-
of
-
pipe section.

A simple means to reduce the potential for HCB emissions is the choice of oil
-

and chlorine
-
free feeds, but it is not everywhere possible.

Pre
-
treatment operations prepare the material for smelting and include sorting, proces
sing,
and cleaning. The goal is to separate aluminium from contaminants (other metals, dirt, oil,
plastics, and paint). Feed sorting allows suiting furnace type and emission abatement:
unsuitable raw materials are transferred to other facilities better sui
ted for their treatment. The
removal of oil, organic material (plastics), and chlorine is achieved by thermal means (swarf
centrifuge, swarf drying or other thermal de
-
coating techniques). Avoidance of these
compounds in the feed reduces the generation of
HCB during incomplete combustion.

Smelting and combustion processes should be monitored by control systems to guarantee
stable and optimal operations. Effective burners and furnaces (high
-
temperature advanced
furnaces) are needed. Monitoring HCB emissions
by continuous sampling should also be
considered. At the same time, other parameters such as temperature, residence time, and gas
components should be continuously controlled and maintained
(UNEP, 2006)
. Peak
combustion rates from included organic materials need to be taken into account
(European
IPPC Bureau, 2001)
.

Chemical additions for damaging and degassing (chlorine mixtures, chlorid
es) (chlorine
mixtures, chlorides) can lead to the formation of HCB. In these processes, injection of liquid
chlorine or hexachloroethane has to be avoided (the use of hexachloroethane is banned in
Europe). Careful choice for chemical damaging is required
since practical, health, and safety
considerations have also to be taken into account. For instance, the use of chlorine mixed with
argon or nitrogen or the use of aluminium fluoride is a possibility
(European IPPC Bureau,
2001)
. Off
-
gases have to be treated
.

Artisanal and other small
-
scale aluminium recovery should be discouraged in favour of
larger
-
scale secondary aluminium smelting operations where proper air pollution controls can
be implemented
(UNEP, 2006)
. When small
-
scale processes are practised, the following
measures should be applied: feed sorting, selecting a better fuel supply (oil or gas fuels
instead of coal), filtration of
exhaust gases, proper management of wastes and proper choice
of chemical additions (degassing/damaging).

Furthermore, some of emerging techniques quoted by European IPPC Bureau
(2001)

could
participate in decreasing eventually HCB emissions.
Scrap sorting using laser and eddy
current technology is being tested. Refining with rotary flux or gas injection leads to more
controlled flux additions and has been implemented at some plants.



Technical feasibility

There are no technical limitations to i
mplement the mitigation measures discussed for
secondary aluminium processing. But they are more adapted for larger
-
scale recovery
facilities.

Options for reducing emissions: HCB


19



Performance

There are no figures available for the performance of the measures in terms of decreasing
HCB emissio
ns. Indeed, data are focused on dioxins and furans (other chlorinated
compounds).

In general, feed sorting will prevent or minimise the use of chloride salt fluxes during
smelting, and thus further chlorinated emissions. Feed cleaning reduces the potential

for the
emissions of HCB; as well, the melting of cleaned material can save energy and reduce
skimming generation
(European IPPC Bureau, 2001)
. The control of combustion and smelting
and the limitation of damaging impacts by careful choice of the demagging
approach will
decrease the emissions of chlorinated compounds, including HCB.

According to UNEP
(2006)
, artisanal and

other small
-
scale aluminium recovery processes
may release many chemicals into the environment, including persistent organic pollutants
(HCB).



Costs

They are few figures available.

European IPPC Bureau
(European IPPC Bureau, 2001)

estimated the investment c
osts of a
30
-
ton furnace with gas injection to 2.73

M€
1997

and the operational cost savings (energy,
fluxes, treatments, and improved yield) at 1.26

M€
1997
/y.

The process equipment costs of a rotary furnace ranged between 15 and 60 €/year ton. For a
reverb
atory furnace, the investment costs of an advanced system (pumping system and charge
well) were estimated at 0.46

M€
1997
.



State of the art

All these techniques are regarded as BAT for secondary aluminium processing with many
applications.

(ii)

Chemical manufact
uring (chlorine chemistry)



Description of the process

Chlorine chemistry involves chemical industries which use chlorine as a product or an input
(raw material, intermediate). Chlorination processes


most of them involve a hydrocarbon
(saturated or unsatu
rated) treated with chlorine generally along with a catalyst


are used in
the synthesis of hundreds of industrial and speciality chemicals
(Wiley Interscience, 2000;
World Chlorine Council, 2002)
.

In chemical manufacturing, HCB may occur when aromatic materials and chlorine are
present. Generation should be favoured in processes that use elemental chlorine, elevated
temperature,
alkaline conditions, and a source of free radicals and when oxygen or
oxygenated materials are excluded.

According to UNEP
(2006)
, main potential sources of HCB are: uncontrolled combustion
(incomplete combustion); electrolysis reactions with graphite electrodes; processes with
dehydrohalogenation of chlorinated aliphatic rings (e.g. hexachlorocyclohexane); chlorination
Options for reducing emissions: HCB


20

reactions of materials with benzene as an impurity; and processes using HCB as a raw
material (HCB residues in the final product). Carbochlorination reactions (e.g. MgO to
MgCl
2
) might also be a source.

Oxychlorination processes can also be a potential sou
rce of HCB due to the presence of heat,
elemental chlorine, copper chloride catalyst and organic material (aromatics may be already
present or generated in high
-
temperature processes)
(UNEP, 2006)
. However, HCB can be
completely removed by distillation and isolated in high
-
boiling materials (“heavy ends”
fraction). That particularly applies to the manufacture of chlorinated solvents
(tr
ichloroethylene, perchloroethylene and carbon tetrachloride) which involves chlorination,
oxychlorination, and pyrolysis and where modern techniques allow separating HCB from the
final product (HCB < 20

ppb for trichloroethylene and < 10

ppb for perchloroe
thylene).
Finally, appropriate treatments of heavy ends (hazardous waste incineration or thermal or
catalytic destruction) do not lead to HCB emissions.

Furthermore, when chlorine is used as an intermediate (no chlorine in the final product),
process is no
t thought to be a major source of HCB emissions.



Mitigation measures

Mitigation measures to limit HCB emissions are
(summary of UNEP, 2006)
:

-

Implementing green chemistry,

-

Careful operations and rigorous maintenance,

-

Process modification to reduce HCB generation,

-

Treatment of impurities in raw materials,

-

Purification of products by distillation,

-

Recycling uni
ntentional HCB generation,

-

Appropriate waste management (end
-
of
-
pipe techniques)


Implementing green chemistry and engineering is a general principle for the design of
products and processes that reduce or eliminate the use and generation of hazardous
subs
tances (including HCB). It supports both better economic and environmental performance
and is based on principles such as a more efficient use of raw materials and a minimisation of
by
-
products and waste. More generally, some HCB sources may not be identif
ied and related
to a particular chemical process: in this view, release prevention can be achieved by installing
high
-
performance technologies, closing the cycles and installing internal and external control
of by
-
product, waste streams, and emissions.

Car
eful operations and rigorous maintenance improve process yields and contribute to reduce
by
-
product generation. For instance, controlled combustion is a means to avoid incomplete
combustion and the emissions of HCB. For chlorination reactions, careful cont
rol of reaction
conditions (e.g. temperature, chlorine feed rate and purity of catalyst) may lead also to
significant reductions of HCB contamination. Appropriate packing and maintenance (regular
change) of fixed bed oxychlorination catalysts can reduce ho
t spots, fouling of the catalyst
bed, loss of productivity and the potential for generation of undesired products (including
HCB). With fluidised bed reactors, better temperature control and more uniform performance
can be achieved, but adherence of HCB to

catalyst particles can allow for carry
-
over within
the facility when catalyst particles are entrained in the vapour stream.

Options for reducing emissions: HCB


21

Process modification to reduce HCB generation includes changes in modus operandi and in
raw materials. For instance, carbon electro
des for chlor
-
alkali production (manufacture of
chlorine and caustic soda) have to be replaced by coated titanium anodes. For the production
of pentachlorophenol and sodium pentachlorophenate, the routes using HCB as a raw material
(pentachlorophenol: hydr
olysis of HCB with sodium hydroxide or thermolysis of HCB;
sodium pentachlorophenate: hydrolysis of HCB) have to be avoided (normally in Europe,
such routes are not used anymore). Other routes should be preferred (pentachlorophenol:
chlorination of phenol
by Cl
2

over a catalyst; sodium pentachlorophenate: treatment of
pentachlorophenol by sodium hydroxide).

Treatment of impurities in raw materials is of particular interest for oxychlorination process.
Acetylene as an impurity in HCl (resulting from the ethy
lene dichloride cracking process) can
eventually be converted during oxychlorination to chlorinated aromatics (including HCB).
Selective hydrogenation of this acetylene to ethylene and ethane prior to the oxychlorination
reaction is a common measure to avo
id this by
-
product synthesis. As well, some patents state
ways to remove aromatics in feed materials before oxychlorination in order to reduce the
production of inadvertent by
-
product (including HCB). Note that patented technology is
proprietary, which as
a result limits its implementation.

Distillation is used primarily to produce product of purity appropriate to downstream
processing. But it is also a means of separating desired product from inadvertent by
-
products.
The latter can be minimised by appropri
ate design and operation of the distillation apparatus,
even though boiling points between the commercial product and by
-
products are not so
widely separated. In the specific case of HCB, its boiling point is sufficiently different from
commercial products

to achieve complete separation.

Recycling is also a solution to consider in some cases. Destruction of chlorinated by
-
products
such as HCB, indeed, can allow for HCl recovery.

The end
-
of
-
pipe solutions are discussed in the end
-
of
-
pipe section.



Technical
feasibility

There are no technical limitations to implement the mitigation measures discussed for
chlorine chemistry.



Performance

All the presented measures should participate to decrease HCB emissions; but there are no
figures available for the performanc
e of a particular measure in terms of decreasing HCB
emissions. Indeed, data are focused on dioxins and furans (other chlorinated compounds).

Based on Bailey’s estimations
(2001)
, HC
B contamination, with best techniques, could be
estimated in chlorinated solvents as low as 1

ppb and in chlorinated pesticides in the order of
50

ppm (see
Table
7
), even likely significantly lower for pesticides

used in Europe.



Costs

They are no figures available. But the costs of measures should be manageable at the facility
scale.


Options for reducing emissions: HCB


22



State of the art

All these techniques are regarded as BAT for chlorine chemistry with many applications.

(iii)

Fossil fuel
-
fired utility
and industrial boilers (combustion)



Description of the process

Utility and industrial boilers are facilities designed to burn fuel to heat water or to produce
steam for use in electricity generation or in industrial processes
(UNEP, 2006)
. There are
significant differences between utility and industrial boilers in terms of boiler size, boiler
design, and applications for output steam. T
his has direct consequences for recommending
best techniques.

Most boilers use fossil fuels as an energy source, but they can also be designed to burn
biomass and wastes, in general with co
-
firing with fossil fuels. Fossil fuels can be light or
heavy fuel
oil, natural gas, coal, or lignite. High
-
energy wastes are materials such as used oil,
tyres, and spent solvents, which can be used to replace fossil fuels as a source of thermal
energy. Low
-
energy wastes such as dewatered sewage sludge are co
-
incinerated
for disposal.
Biomass consists of wood, wood waste, materials from agricultural crops and other biomass
materials like black liquor in pulp mills.

HCB emissions per unit of fired fuel are thought to be very low and often undetectable (below
the detection l
imits of available analytical methods). But the total mass emissions from the
boiler sector may be significant because of the scale of fossil fuel combustion, in terms of
both tonnage and distribution.



Mitigation measures

Mitigation measures to limit HCB e
missions are
(summary of UNEP, 2006)
:

-

Ensuring efficient combustion,

-

Excluding contaminated fuels,

-

Gas
-
cl
eaning and appropriate strategies for disposal (end
-
of
-
pipe techniques)


Efficient combustion can be achieved in controlling the key parameters (e.g. temperature:
over 900°C; turbulence: high; oxygen: in excess) to maintain the combustion conditions
within

the boiler at the optimum and ensuring that sufficient time (over 1 second) is allowed
for complete combustion. A good indicator for assessing the combustion efficiency is the real
-
time monitoring of CO gas (good combustion = low CO emissions).

Measures s
uch as controls (e.g. measurement of the fuel chlorine content) should be
undertaken to ensure that fuel is not contaminated with chlorinated aromatics (PCB, HCB) or
chlorine, and other components which could act as catalysts in the formation of HCB. But f
or
instance, chlorine removal from fossil fuel feeds is not seen as a cost
-
effective measure for
PCDD/PCDF reduction
(UNECE, 1998)
, and likely for HCB. Potential fuel contami
nation
occurs in particular with low
-
energy wastes where undesirable materials or pollutants are
present.

The end
-
of
-
pipe solutions are discussed in the end
-
of
-
pipe section.


Options for reducing emissions: HCB


23



Technical feasibility

There are no technical limitations to implement the mitigat
ion measures discussed for boiler
combustion.



Performance

All the presented measures should participate to decrease HCB emissions; but there are no
figures available for the performance of a particular measure in terms of decreasing HCB
emissions. Indeed,
data are focused on dioxins and furans (other chlorinated compounds).



Costs

They are no figures available. But the costs of measures should be manageable at the facility
scale.



State of the art

All these techniques are regarded as BAT for combustion sector

with many applications.

b)

User
-
oriented options: Pesticide application

Here are described the measures for limiting the emissions of HCB by pesticide users
(farmers

using authorised pesticides

containing
HCB impurities
: picloram or chlorothalonil
).

(i)

Descrip
tion of the phenomenon

Past or present application of HCB
-
contaminated chlorinated pesticides results in HCB
-
contaminated soils, which then contaminate water during runoff (HCB dissolved in runoff
water) and erosion (HCB adsorbed to eroded soil particles)
events in the fields. Water runoff
is the downslope flow of rainfall (or other water) that is not absorbed into the soil, and soil
erosion by water is the detachment and transport (mainly by runoff water, at the margin by
rainsplash) of particles from the
soil surface. In those events, however, HCB losses can be
considered to be mainly due to the latter, since HCB is an insoluble strongly adsorbed
substance (relatively high Koc)

and

the presence of organic matter influences the
concentrations of POPs in soi
ls (Meijer et al., 2003).

Like surface runoff, erosion can occur on most arable fields, but its importance (frequency,
range) depends on many factors such as climate (high precipitation: increasing), soil type (silt
or fine sand: increasing), soil structu
re (high: decreasing), field slope (high: increasing),
agronomic practices (good: decreasing), or vegetation cover (high: decreasing).

The options discussed further address the limitation of soil erosion by water and rely
particularly on Reichenberger
et a
l.
’s synthesis
(2006)

achieved for European project
FOOTPRINT. They are similar to those presented to reduce isoproturon pollution by runoff
(SOCOPSE report on iso
proturon).


(ii)

Mitigation measures

They are several measures to reduce HCB water pollution by soil erosion due to past and
present pesticide application.

Options for reducing emissions: HCB


24



Present pesticide application:

-

reducing application rate/frequency,

-

shifting application date (earlier or

later),

-

banning application along the edge of rivers/fields,

-

controlling sprayers regularly.




Past and present pesticide application:

-

applying conservation tillage,

-

covering the ground (cover crops, mulching),

-

planting vegetated buffer strips (grassed wat
erway, hedge, riparian zone…),

-

implementing constructed wetlands.


The use of environmental buffers (planting vegetated buffer strips, implementing constructed
wetlands) is basically an end
-
of
-
pipe technique and so will be discussed in the end
-
of
-
pipe
sect
ion.

Reducing application rate is merely a decrease in amount per hectare of chlorinated
pesticides, which might be contaminated by HCB (during the manufacture). As a result, the
amount of HCB reaching the soil surface is reduced, and consequently also los
ses from field
erosion. Reduction is all the easier than the use of pesticides is optimised. This can be
achieved for example with band spraying on row crops and mechanical inter
-
row weed
control, or by applying the only necessary amount with a variable
-
ra
te sprayer connected to
geographic information system and vehicle guidance system.

Shifting application date is a modification (anticipation or delay) of date application in such a
way to avoid pesticide application in periods with a high probability of er
osion events (due to
high
-
intensity rainstorms or saturated soils).

Conservation tillage, including zero
-
tillage, is an agronomic practice where tillage is reduced,
and even suppressed, which leaves at least 30

% of the soil covered by crop residues. Plant
ing
cover crops is another agronomic practice and consists in growing (in fall/winter) any crop
between regular grain crop production periods to provide soil cover. Both these techniques are
designed to prevent soil erosion by wind and water.

Regular indep
endent inspection of sprayers is also a means of reducing the loss of pesticides
and avoiding over application. This action, indeed, forces to keep equipment well maintained
and consequently reduces unintended release. In 2004, the inspection of sprayers w
as
mandatory in Belgium, Denmark, Germany, Luxembourg, the Netherlands, Poland, and also
Switzerland
(H
uyghebaert

et al.
, 2004)
.

(iii)

Technical feasibility

The technical feasibility of identified mitigation measures for preventing erosion and HCB
pollution is synthesised in
Table
9
.



Options for reducing emissions: HCB


25


Table
9
:
Technical feasibility of erosion mitigation measures

Mitigation measure

Feasibility

Application rate reduction

Easy to implement

Possible risk of insufficient weed control

Shifting application date

Easy to implement

Possible risk of insufficient weed con
trol (risk increases
with requirement of only one application per crop)

Conservation tillage

Easy to implement

Not everywhere possible

Possible risk of fungal disease (in humid climate)

Ground cover

Easy to implement

Regular inspection of sprayers

Easy
to implement

Sources: Reichenberger
et al

(2006)


(iv)

Performance

The performance of identified mitigation measures for preventing erosion and HCB water
pollution is
shown in
Table
10
. The reduction efficiency concerns only emissions to water.


Table
10
: Performance of erosion mitigation measures

Mitigation measure

Performance

Application rate reductio
n

Current application: Reduction of HCB emissions about
equivalent to the pesticide application reduction

Past application: no reduction of HCB emissions

Shifting application date

Current application: Reduction of HCB emissions
variable (low to high)

Past

application: no reduction of HCB emissions

Conservation tillage

Past and current application: Reduction of HCB emissions
unknown

Ground cover

Past and current application: Reduction of HCB
emissions unknown

Need for more energy (fuel)

Regular inspectio
n of sprayers

Current application: Reduction of HCB emissions due to
loss, drift and over application of pesticides

Past application: no reduction of HCB emissions



(v)

Costs

For application rate reduction and shifting application date, there are no investme
nt costs;
operational costs include a possible loss of crop yield (due to the possible insufficient weed
control)

and, in the case of
shifting application date, there are possible additional
management
costs due to
a concentration of tasks for a limited pe
riod
. Note that in case of reducing
application rate, avoided costs (pesticides saved) have to be taken into account.

In case of conservation tillage, there are investment costs if the classical farm equipment
cannot be used. Operational costs could be due

to a loss of crop yield or a need for fungicide
Options for reducing emissions: HCB


26

treatment but avoided costs (fuel, work, and time saved) have to be removed. Depending on
assumptions (equipment, need for additional treatment, loss of crop yield, market prices…),
the yearly extra costs sh
ou
ld be in the range of 0
-
50

€/ha
(Chamber of Agriculture, 2007)
.

With a ground cover, there are no in
vestment costs. The operational costs ca
n be roughly
estimated at 109

€/ha (seedbed: 53

€/ha; seeds: 23

€/ha; and mechanical destruction: 33

€/ha)
but some benefits have also to be considered (e.g. nitrate trapping and improvement of soil
structure)
(Chamber of Agriculture, 2007)
.

The costs of inspection of sprayers include the cost of inspection itself as well as the costs of
repairing the fa
ulty sprayers. To give a magnitude of order for inspection costs, a voluntary
diagnosis of sprayer costs in France about 100


(Dour hon douar, 2002)
.

(vi)

State of the art

All erosion mitigation measures have been implemented with success. They all concern best
practices in European agriculture.

c)

Alternatives options

HCB as a substanc
e has not been used for many years in Europe and some alternatives have
been implemented since the 1970s. As an example, the past use as a fungicide is discussed
below.

The use of HCB as a fungicide included seed treatment and the control of diseases. Chem
ical
substitution for HCB was developed in the early 1970s. And when HCB was banned in the
EU as a plant protection product in 1981, some substitutes were available. UNEP
(2007c)

in
POPs Database on Alternatives lists some possible substitutes. In particular, bitertanol,
carboxin, and fuberizadole substitute fo
r fungicide seed treatment; bitertanol, fuberizadole,
and guazatine for control of bunt (wheat diseases); and carboxin for control of maydis (maize
diseases). As well, other systemic fungicides than carboxin have since been marketed for seed
treatment such

as difenoconazole and tebuconazole
(Mathre, 2000)
. Besides chemical
substitution, some disease
-
resistant wheat varieties were developed
(2007c)

with no need for
fungicides. As a result, HCB as a plant protection product has been entirely substituted in
Europe.


5.2

En
d
-
of
-
pipe options for the substance

With waste

containing HCB, some
filtering
technologies for removing HCB such as
catalytic
bag filters
or adsorption on granular activated carbon filters (GAC) can be applied.

We also
provide
soil
-
oriented options as
environmental buffers
and
soil
dechlorination.

All these end
-
of
-
pipe techniques are assessed below.

Options for reducing emissions: HCB


27

a)

Industrial end
-
of
-
pipe te
chniques

(i)

Filtering

This technique should be considered for treating HCB
-
contaminated waste in case of
industrial sites (secondary aluminium processing, combustion, incineration) or large waste
treatment plant.



Description

Filtering off
-
gases of secondary a
luminium processing and combustion is an option to
consider. Filtering can be achieved with activated carbon filter to adsorb chlorinated
aromatics like HCB to the surface of solid, highly porous particles of activated carbon
(
European IPPC Bureau, 2003)
. When adsorption capacity of activated carbon is exhausted, it
has to be replaced by fresh material. Note that facilities for activated carbon are necessary.

Activated carbon can be used as powder (PAC) dosed to a treatment tan
k or as granulate
(GAC) in columns, where both tank and columns are built of corrosion
-
resistant material.
Normally GAC is regenerated by thermal reactivation whereas PAC, not regenerated,
becomes part of the waste.

Instead of carbon filter, catalytic bag
filters with polytetrafluoroethylene membrane can be
used (current applications in waste incineration, crematoria, metal industries and cement
plants). These filter bags contain or are impregnated with a catalyst and can operate at
temperatures between 180
° and 250° C without the addition of activated carbon. In this
process, HCB will be destroyed on the catalyst rather than adsorbed on the activated carbon
and discharged as solid residues.

Other filtering includes the use of fabric or ceramic filters, whic
h are particularly efficient for
dust removal.



Technical feasibility

No specific restrictions applying to catalytic bag filters are reported.

With activated carbon, an upstream filtration (e.g. bag filter) can be needed to be free from
solid content since
the active surface is liable to clogging and blockage
(European IPPC
Bureau, 2003)
. PAC is usually preferred in case of intermittent or variable pollution or
emergency, and GAC is used in the other cases. For HCB, GAC should b
e the better.

Activated carbon can be operated at various conditions (pH, temperatures, organic carbon
concentrations…) with automated systems but the removal efficiency would varied. Note that
low extra space is needed for this technique.

The following li
mits and restrictions apply to activated carbon: the total suspended solids and
the pollutant concentration are to be, respectively, <20 mg/l and <100 g/l with GAC, and <10
mg/l and <500 g/l with PAC; mixtures of organic compounds may cause a significantly

reduced adsorption capacity; high content of macromolecular compounds decreases efficiency
and may cause irreversible blockage of active sites; and PAC has to face major erosion
problem due to scouring effect in the activated sludge.


Options for reducing emissions: HCB


28



Performance

There ar
e no figures available for the removal efficiency of HCB by activated carbon or
catalytic filters.

However, according to applications at German and Japanese crematoria, HCB emissions with
catalytic filters should be below 0.1

ng

I
-
TEQ/Nm
3

{{UNEP, 2006 #7}}
.

High abatement should also be achieved with activated carbon since HCB, like dioxins and
furans, has a very high probability of being adsorbed. HCB concentration should be below
0.1

ng

I
-
TEQ/Nm
3

{{UNEP, 2006 #7}}. Furthermore, most of other priority subs
tances
(heavy metals, pesticides, PAHs, nonylphenols…) can be removed at the same time.

Along with activated carbon, cross
-
effect is the disposal of spent material. PAC as well as
GAC contaminated with HCB (no recovery possible), indeed, has to be incinera
ted.



Costs

For activated carbon filters, capital costs are generally high, and operational costs medium.
The same applies to catalytic filters.



State of the art

Activated carbon or catalytic filters are regarded as a BAT for waste treatment with many
appli
cations related to secondary aluminium processing and combustion sector.

b)

Sedimentation



Description

It consist of
separating of suspended particles and floating material by gravitational settling.
The settled solids are removed as sludge from the bottom, wh
ereas floated material is
skimmed from the water surface. When the particles cannot be separated by simple
gravitational means, e.g. when they are too small, their density is too close to that of water or
they form colloids, special chemicals are added to
cause the solids to settle (BREF Common
Waste Water and Waste Gas Treatment).

These chemicals cause the destabilisation of colloidal and small suspended particles (e.g. clay,
silica, iron, heavy metals, dyes, organic solids, oil in waste water) and emulsio
ns entrapping
solids (coagulation) and/or the agglomeration of these particles to flocs large enough to settle
(flocculation). In the case of flocculation, anionic and non
-
ionic polymers are also used. The
influence of coagulation is shown as an example in

Table 3.2 [cww/tm/27]. The removal
levels in this table, however, should not be confused with achievable performance rates of a
treatment technique.




Technical feasibility

Sedimentation is a separation technique widely used for many purposes and usually n
ot used

alone.

Sedimentation techniques require s
imple installation and thus do not tend to failure. With
flocculation, a mixing chamber is added. Picket fence or low
-
speed mixers are used,

causing hydraulic mixing within the fluid as it flows through the
tank. Partial recycling of the

floc back into the flocculator can result in a better floc structure and optimum exploitation of

Options for reducing emissions: HCB


29

flocculant. To ensure optimum settling operation, an upstream oil separation or emulsion
decomposition stage, etc., is normally
installed to remove interfering substances. The
equipment of the sedimentation facilities needs to be such that there is no waste water
transference into the ground, at least when the tank might contain substances hazardous to
groundwater. Storage faciliti
es for the coagulant / flocculant chemicals and the sedimented
sludge need to be equipped to suit the characteristics of the sludge.

Sedimentation techniques are unsuitable for fine material and stable emulsions, even with
coagulants and flocculants. Besi
des, floc can embed other contaminants that might cause
problems in disposing of the sludge.


Application limits and restrictions are :

-
Particle size

: particles must be large enough to be settleable, otherwise coagulation and/or
flocculation chemicals ne
ed to be applied

-
Presence of volatile substances

: volatile substances need to be avoided because of the long
residence time in the tank (as well as the mixing action when coagulation and/or flocculation
are used) and thus the potential release of VOC

-
So
lid concentration

: no limits, provided the aqueous phase is still separable pH (in the case
of coagulation / flocculation) controlled pH range is essential during operation, otherwise
poor clarification performance

-
Emulsions

: stable emulsions cannot be
separated and broken by coagulation / flocculation;
preceding emulsion breaking is required




Performance

When sedimentation is used upstream of subsequent treatment steps, its purpose is to protect

downstream facilities, so its removal efficiency needs to
be high enough to achieve that.
When it is used as a final treatment, its performance depends on the properties of the particles
to be removed.


Table
11

: Removal of Waste Water Contaminants under Influence of Coagulation


Substance

removal (%)

Inorganic mercury

70

Cadmium and compounds

98

DDT [1,1,1
-
trichloro
-
2,2
-
bis
-
(p
-
chlorophenyl)ethane]

75
-
80

HCB (hexachlorobenzene)

59

Aldrin

100

Dieldrin

50

Endrin

43

PCBs (polychlorinated biphenyls)

30

40

Tributyltin compounds

>90

Tri
chloroethene

36

Perchloroethene

30

Source: BREF Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector
(2003)




Costs



Capital costs

[million]


Operating costs

Sedimentation tank

EUR 1.2
a


BEF (Belgium Francs) 4.8
b 1

BEF 4
c

BEF 20

100 per m
3

Options for reducing emissions: HCB


30

a
per 1000 m
3

tank volume

b
capacity of 100 m
3
/h

c

capacity of 25 m
3
/h

1

[cmm/tm/128]

BEF: Belgium Francs

Source: BREF Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector
(2003)




State of th
e art

In the case of HCB emissions, sedimentation is regarded as a BREF.


c)

Environmental buffers

(i)

Description

Environmental buffer between the cropland and the water body is a means of reducing the
impact of erosion by trapping eroded particles. It acts as
a runoff water biofilter. Buffers can
be a grassed waterway which is a grassed buffer strip installed in up
-
and
-
down direction,
typically inside the field, and where surface runoff waters with eroded particles are directed to
it. They can also be vegetated

buffer strips along field edges and riversides (grassed strips,
hedges, riparian zones). As well, the buffer can be a constructed wetland, an artificial marsh
or swamp and habitat for wildlife, which filters waters as natural wetlands do.

(ii)

Technical feasib
ility

The technical feasibility of end
-
of
-
pipe measures for mitigating erosion and HCB pollution is
synthesised in
Table
12
.

Table
12
: Technical feasibility of end
-
of
-
pipe measures for miti
gating erosion

Mitigation measure

Feasibility

Grass strips, hedges

Easy to implement

Need for maintenance

Loss of arable land area for the strip

Riparian zones

Easy to implement and unneeded maintenance

Slow growing (trees)

Possible increase of pest/dise
ase pressure

Constructed wetlands

Easy to implement

Need for maintenance

Not everywhere possible

Loss of arable land area

Possible classification by authorities as a protected habitat

Sources: Reichenberger
et al

(2006)


(iii)

Performance

Environmental buffers abate the emissions from both past and present pesticide applications.
But the performance of environmental buffers for mitigating HCB water pollution is unknown
(no study available). However, it can be assumed that, like for most pesticides, grass strips,
hedges and constructed wetlands should be more efficient to reduce HCB emissions than
riparian zones.

Options for reducing emissions: HCB


31

(iv)

Costs

The costs of some vegetated buffer strips are shown i
n
Table
13
. In case of hedges, the
investment costs can be decreased down to 2
-
3

€/m hedge with a simple restoration without
planting. For all vegetated buffer strips the operational costs may also include the lo
ss of crop
yield (due to the loss of arable land area). To calculate this cost, Ecolas
(2005)

retained the
purchase price of the agricultural land (average price: 13,000

€/ha), which can be seen as an
approximation of the net present
value of the agricultural yield achievable on that land in the
future.


Table
13
: Cost evaluation of vegetated buffer strips (€ per hectare or meter)

Mitigation
measure

Capital costs

Operational costs

Type

Amount

Type

Amount

Grass

strips
(€/ha strip)

Soil cultivation (4h)

176

Mowing (2h)

88

Seedbed (5h)

53



Seeds (40 kg)

244



Total

473

Total

88

Hedges (€/m
hedge)

Planting (1.2 plant)

12

Maintaining

1.6

Total

12

Total

1.6

Sources: adapted from Chamber of Agriculture
(2007)

and Ecolas
(2005)
;

Note: 1

hour soil cultivation = 44

€; 1

hour seedbed = 10.67

€; 1 kilogram grass seeds = 6.1

€; 1

hour mowing =
44

€; planting 1 hedge plant = 10

€.



Constructed wetlands entail high capital costs. Operational costs include the maintenance
costs and, if t
he wetland is constructed on arable land, the loss of crop yield (due to the loss of
land).

(v)

State of the art

All these end
-
of
-
pipe measures for mitigating erosion have been implemented with success.
Moreover vegetated buffer strips are regarded as best pra
ctice in the European agriculture.


d)

Soil remediation

(i)

D
escription

Dechlorination is the key reaction for the degradation

of chlorinated benzenes
. It

is related to
the presence of electron donors in the system, namely
f
ormate, lactate and pyruvate (Nowak
et

al., 1996; Adrian et al., 1998; Chang et al., 1998).
T
he dechlorination of HCB
may be
enhanced by the addition of organic electron donors to the soil
whereby wheat straw dust
seems to
g
i
ve the best results (Rosenbrock et al., 1997
)
.


(ii)

Technical feasibility

No literature on
dechlorination technique

applications
apart from
the research field.


Options for reducing emissions: HCB


32

(iii)

Performance

The dechlorination of HCB in batch cultures, sewage sludge, sediment and soil slurry is well
documented, but there exists only few information about the dec
hlorination of HCB in
agricultural soils. According to Brahushi et al. (2004), the nature of the organic matter in the
soil seems to strongly influence the dechlorination capacity and further research are needed to
investigate the interrelationship of diff
erent soil types, different additional carbon sources and
the dechlorination process
(Xingbao et al., 2008)
.


(iv)

Costs

No information


(v)

State of the art

This end
-
op pipe option
is still under investigation at the research level
.


e)

Sector specific techniques



Se
condary aluminium processing

The collection and treatment of off
-
gases is a general principle to be followed. For the
treatment itself, available techniques are the use of afterburners with rapid quench, activated
carbon adsorption and dedusting fabric fil
ters.

Afterburners are used to destroy organic material produced in the furnace or pre
-
treatment
stages. They are specially recommended after the thermal decoating and de
-
oiling processes
for oil removal
(European IPPC Bureau, 2001)
. As well, carbon may be a
dded in the collected
off
-
gases and efficient dust filtration (by fabric or ceramic filters) can be used to remove
organic material and dioxins that are associated with particulate matter. In particular, the
injection of activated carbon together with lime

can reduce acid gases and organic carbon
including dioxins.



Chemical manufacturing (chlorine chemi
stry)

D
estruction and end
-
of
-
pipe systems are defined by regulation

and additional information is
given in

BREFs on large

volume

organic chemical processes and on tr
eatment of water and
gas outputs from the chemical

sector. In general, best available techniques for airstreams can
involve recovery and recycling of HCl,

combustion of trace volatiles, scrubbing of incinerator
output streams with water, alkaline solutions

or

dry alkali, and addition of activated carbon
and baghouses for removal of particulate. These may be

used alone or in combination.
Treatment of water streams can involve stripping and recovery

(condensation or absorption)
of volatile materials from wate
r.

Subsequent biological purification of water streams with
removal of solids is done in a dedicated

water treatment system (UNEP, 2006).



Fossil fuel
-
fired utility and industrial boilers (combustion)

For combustion facilities, the possible techniques are t
he implementation of appropriate gas
-
cleaning methods to lower emissions that may contain entrained pollutants; and appropriate
strategies for disposal, storage or ongoing use of collected ash.

Options for reducing emissions: HCB


33

For residues containing higher levels of contamination, severa
l techniques are recommended
for reduction of persistent organic pollutants before disposal. These include catalytic
treatment at low temperatures and with reduced oxygen concentrations, extraction of the
heavy metals and combustion to destroy organic matt
er, vitrification and plasma technology
(UNECE, 1998)
.



Open burning of waste, including burning of landfill

sites

Techniques which may
lower HCB
emissions
, with respect to the materials burned: avoid

including non
-
combustible materials, such as glass and bulk metals, wet waste and materials
of low

combustibility; avoid waste loads containing high chlorine content, whether inorganic
chloride such

as

salt, or chlorinated organics such as PVC; and avoid materials containing
catalytic metals such as

copper, iron, chromium and aluminum, even in small amounts.
Materials to be burned should be dry,

homogeneous or well blended, and of low density, such
as n
on
-
compacted waste.

With respect to the burning process, aims should include: supply
sufficient air; maintain steady

burning or rate of mass loss; minimize smouldering, possibly
with direct extinguishment; and limit

burning to small, actively turned, well
-
ventilated fires,
rather than large poorly ventilated dumps or

containers

(UNEP, 2006)
.

Options for reducing emissions: HCB


34

6.

Options for reducing emissions: synthesis

The next table enables to observe principal emission sources and media through which DEHP
may reach the aquatic environment.

Then, the following table aims at making
correspondences between the main emission sources and available mitigation options.

Table
14

: Main pathways to the aquatic environment for HCB


Pathways to the aquatic environment


Air

Land

WWater

Direct

Manufacturing / industrial use of products
(secondary aluminium processing ; chemical
manufacturing,…)

32%


?

10%

Residential, road transport, other mobile sources,
and machinery

?



?

Combustion of fossil fuels




Low

Waste treatment pl
ant

3%



5%

Pesticide application

23%

?


15%

Waste incineration

3%




Land filling of wastes


?



TOTAL (tonnes per year)

?

25


7 ?

%: pourcentage of emissions eventually reaching the aquatic environment (the sum equals 100%)


Taking atmospheric depos
ition into account, manufacturing processes and pesticide
applications are the primary sources of HCB concentration in water. Far behind are waste
treatment, combustion of fossil fuels and, nowadays, motor vehicles. In order to reduce these
emissions, some

source control and end
-
of
-
pipe options are available or under investigation
(see next table) but some important sources appear not give rise to as many mitigation options
as we could expect. We particularly think of process
-
oriented options to lower impur
ities in
pesticides or user
-
oriented options to improve the use of solvents. Finally, motor vehicle
emissions should call for innovative options too.

Table
15

and
Table
16

synthesise main sources and possible emission abatement measures,
and assessment of source abatement measures, respectively.


Table
15

: Emission sources and possible emission abatement measures


Sources

Secondary
aluminium
pr
ocessing

Chemical
manufacturin
g

Combustion

Pesticide
application

Waste
treatment

Measures

Source control






Choice of oil
-

and
chlorine
-
free feeds

X


X



Pre
-
treatment of feed
material

X

X




Combustion control

X


X



Limitation of demagging
im
pacts

X





Closure of small
-
scale
facilities

X

X




Options for reducing emissions: HCB


35

Implementing green
chemistry


X




Careful operations and
rigorous maintenance

X

X

X



Process modification


X




Purification of products
by distillation


X




Recycling unintentional
HCB ge
neration


X




Reducing application
rate/frequency




X


Shifting application date




X


Controlling sprayers




X


Conservation tillage




X


Ground cover




X


End
-
of
-
pipe






Vegetated buffer strips




X


Constructed wetlands




X


F
iltering

X

X

X


X

Open burning of waste





X

Soil dechlorination

O

O

O

O

O

Sedimentation





X

Note: X = available measure; O = emerging measure



Table
16

: Measure / source solutions under assessment


Assessment

Remarks

Measure /
source

Technical
feasibility

Performances

Costs

State of the
art


Source
control






Choice of oil
-

and chlorine
-
free feeds


Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

medium

Cnd.:


Lim.:

medium

Imp.:

Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

Numerous

Pre
-
treatment of
feed material

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

wide

Cnd.:


Lim.:


Imp.:

Eff.:


Ot
h.:


En.:


CE:

Yes

W:


IC:


OC:



St:

Yes

App:

Numerous

Combustion
control


Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

wide

Cnd.:


Lim.:


Eff.:


Oth.:

yes

En.:


CE:


W:


IC:


OC:



St:

Yes

App
:

Numerous

Limitation of
Total score:


Total score:


Total score:


Total score:


-

Remark 1

Options for reducing emissions: HCB


36

demagging
impacts

Pol.:

diffuse/point

Rge:

wide

Cnd.:


Lim.:


Eff.:


Oth.:

Yes

En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

-

Remark 2

Closure of
small
-
sc
ale
facilities


Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Implementing
green chemistry

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Careful
operations and
rigorous
maintenance


Total score:


Total score:


Total score:


Total score
:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:

none

OC:

low


St:

Yes

App:

numerous

Process
modification

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/po
int

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Purification of
products by
distillation


Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Recycling
unintentional
HCB generation

Total score:


Total score:


Total score:


Total score:


-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:


Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

Yes

App:

numerous

Reducing
application
rate/frequency



Total score:

+

Total score:


Total score:

++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

medium

Imp.:
medium

Eff.:

variable

Oth.:

Yes

En.:

No

CE:

No

W:

No

IC:

none

OC:

low


St:

Yes

App:

numerous

Shifting
application date

Total score:

+

Total score:


Total score:

++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:
medium

Imp.:
medium


Eff.:

variable

Oth.:

Yes

En.:

No

CE:

No

W:

No

IC:

none

OC:

low


St:

Yes

App:

numerous

Controlling
sprayers


Total score:

++

Total score:


Total score:

++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

low

Imp.:
low

Eff.:

variable

Oth.:

Yes

En.:

No

CE:

No

W:

No

IC:

none

OC:

low


St:

Yes

App:

numerous

Options for reducing emissions: HCB


37

Conservation
tillage

Total score:

0

Total score:


Total score:
++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

high

Imp.:
medium

Eff.:

?

Oth.:

Yes

En.:

No

CE:

No

W:

No

IC:

low

OC:

low


St:

Yes

App:

numerous

Ground cover

Total score:

++

Total score:


Total score:

++

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

low

Imp.:
medium

Eff.:

?

Oth.:

Yes

En.:

medium

CE:

No

W:

No

IC:

none

OC:

medium


St:

Ye
s

App:

numerous

End
-
of
-
pipe






Grass stripes

Total score: ++

Total score:

Total score: +

Total score: ++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

low

Imp.:

Eff.:

?

Oth.:

many

En.:

low

CE:

No

W:

No

IC:

low

OC:

medium


St:

Yes

Ap
p:

numerous

Hedges

Total score: ++

Total score:

Total score:
0

Total score: +

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

low

Imp.:

Eff.:


Oth.:

many

En.:

low

CE:

No

W:

No

IC:

medium

OC:

medium


St:

Yes

App:

numerous

Riparian zones

Total score: ++

Total score:

Total score: +

Total score: +

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

low

Lim.:

medium

Imp.:

Eff.:


Oth.:

many

En.:

No

CE:

No

W:

No

IC:

medium

OC:

low


St:

Yes

App:

numerous

Constructed
wetlands

Total score:

+

Total score:


Total score:

-

Total score:

0

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:
wide

Cmp.:

low

Lim.:

high

Imp.:

Eff.:


Oth.:

many

En.:

No

CE:

No

W:

No

IC:

high

OC:

medium


St:


App:

some

Activated
carbon
adsorption


Total score:

+

Total score:


Total score:
--

Total score:

++

-

Remark 1

-

Remark 2

Pol.:

point

Rge:

wide

Cnd.:

medium

Lim.:

medium

Eff.:


Oth.:

many

En.:

medium

CE:

Yes

W:

Yes

IC:

high

OC:

high


St:

Yes

App:

numerous

Gas filtration

Total score:

Total score:

Total score:

Total score
:

-

Remark 1

-

Remark 2

Pol.:

point

Rge:

wide

Cnd.:


Lim.:


Eff.:


Oth.:

many

En.:


CE:

Yes

W:

Yes

IC:

high

OC:

medium


St:

Yes

App:

numerous

Sedimentation
of solids

Total score: +

Total score:
0

Total score:

Total score: ++

-

Remark 1

-

Remark 2

Po
l.:

point

Rge:
wide

Cmp.:

low

Lim.:

medium

Imp.:

medium

Eff.:

medium

Oth.:

many

En.:


CE:

medium

W:

high

IC:


OC:



St:

Yes

App:

numerous

Afterburners

Total score:

Total score:

Total score:

Total score:

-

Remark 1

Options for reducing emissions: HCB


38

Pol.:

point

Rge:

wide

Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:


App:


-

Remark 2

Open burning of
waste

Total score:

+

Total score:


Total score:


Total score:

++

-

Remark 1

-

Remark 2

Pol.:

diffuse

Rge:

wide

Cnd.:

medium

Lim.:

low

Eff.:


Oth.:

many

En.:


CE:


W:


IC:


OC:



St:

Yes

App:

Numerous

Soil
dechlorination

Total score:


Total score:


Total score:


Total score:

--

-

Remark 1

-

Remark 2

Pol.:

diffuse/point

Rge:

narrow

Cnd.:


Lim.:


Eff.:


Oth.:


En.:


CE:


W:


IC:


OC:



St:

emerging

App:

None

Note:
Pol.

= Typ
e of pollution;
Rge

= Range of concentration;
Cnd.

= Needed conditions;
Lim.

= Limits and
restrictions;
Cmp.

= Complexity of implementation;
Imp.

= Impact on the process, on the factory;
Eff.

=
Efficiency of emission reduction;
Oth.

= Removal of other poll
utants;
En.

= Consumption of energy;
CE

= Cross
effects;
W

= Production of waste;
IC

= Investment costs;
OC

= Operational costs;
St

= Status of the technique
(BAT, existing, emerging);
App.

= Number of applications.




Options for reducing emissions: HCB


39

7.

Conclusion

Most current HCB emission
s to water come from atmospheric deposition. Both point
(industries) and diffuse (agriculture) sources cause pollution by HCB. But the HCB
concentration in the environment is mainly due to historical pollution and accumulation.

During the last two decades,

the production and use of HCB have disappeared in EU member
states. However, some unintended emissions still remain.

There are a number of possible HCB abatement measures, which many of them can be
combined. These options for reducing emissions are about:

-

source control options in industries (secondary aluminium processing, chlorine chemistry,
combustion sector) and in agriculture (pesticide application); and

-

end
-
of
-
pipe options (environmental buffers, waste treatment techniques).

Since HCB is very stable
and widespread in the environment, even if measures for reducing
unintended emissions including end
-
of
-
pipe techniques are taken, it will still remain in the
environment for some years. But as the implementation of the chosen options for controlling
releas
e progresses, the pollution by HCB will decrease, though with a delay.


Options for reducing emissions: HCB


40

8.

Acknowledgements



Funding (European funding, co
-
funding)



Participants to surveys and workshops



Data (EMEP, SOCOPSE Work Package 2)


Options for reducing emissions: HCB


41

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