Water Credit 2

coriandercultureMécanique

22 févr. 2014 (il y a 3 années et 8 mois)

82 vue(s)

The school of Environment and Architecture

University of Shanghai for Science and Technology

22 February 2014

Modern Green

Residential

Quarter

Rating System

(Leadership in Energy


Environmental Design)

LEED



Water Credit 1
:

Water
Efficient Landscaping


Water Credit
2
:

Innovative Wastewater
Technologies


Water Credit 3
:

Water
Use Reduction


Water Efficiency


The contaminants in wastewater are removed
by physical, chemical, and biological means. The
individual methods usually are classified as
physical unit operations, chemical unit processes,
and biological unit processes.


Treatment methods in which the application of
physical forces predominate are known as
physical unit operations.
Screening
,
mixing
,
flocculation
,
sedimentation
,
flotatio
n, and
filtration

are typical unit operations.



Classification of wastewater
-
treatment methods


Treatment methods in which the removal or
conversion of contaminants is brought about by
the addition of chemicals or by other chemical
reactions are known as chemical unit
processes.
Precipitation
,
gas transfer
,
adsorption
,
and
disinfection

are the most common examples
used in wastewater treatment.In chemical
precipitate, treatment is accomplished by
producing a chemical precipitate that will settle.


At the present time, unit operations and
processes are grouped together to provide what is
known as primary, secondary, and tertiary (or
advanced) treatment.


In
primary treatment
, physical operations,
such as screening and sedimentation, are used to
remove the floating and settleable solids found in
wastewater.


In
secondary treatment
, biological and
chemical processes are used to remove most of
the organic matter.




In
tertiary treatment
, additional combinations
of unit operations and processes are used to
remove other constituents, such as
nitrogen
and
phosphorus
, which are not removed by
secondary treatment.
Land
-
treatment

processes combine physical, chemical, and
biological treatment mechanisms and produce
water with quality similar to that from advanced
wastewater treatment.

Influent
wastewater

Grit

Removal

Primary

Settling

Primary

Settling

Aeration

Aeration

Final

Settling

Final

Settling

Disinfection

Sludge to

Processing

Excess

Activated sludge

Final
effluent

Recycle

Process flowsheet for treatment plant designed to meet

secondary
-
treatment standards of

the U.S. Environmental Protection Agency

Contaminant

Unit operation, unit process, or treatment system

Suspended
solids

Sedimentation,Screening, Filtration variations,
Flotation, Chemical
-
polymer addition,
Coagulation/sedimentation, Land treatment
systems

Biodegradable
organics

Activated
-
sludge variations, Lagoon variations,
Intermittent sand filtration, Land treatment
systems.

Pathogens

Chlorination, Hypochlorination, Ozonation, Land
treatment systems.

Unit operations and processes and treatment systems used to
remove the major contaminants found in wastewater

Nutrients:

Nitrogen

nitrification and denitrification variations,
Ammonia stripping. Ion exchange. Breakpoint
chlorination. Land treatment systems.


Phosphorus

Metal
-
salt addition. Lime
coagulation/sedimentation. Biological
-
chemical
phosphorus removal. Land treatment systems
.

Heavy metals

Chemical precipitation. Ion exchange. Land
treatment systems

Dissolved inorganic
solids

Ion exchange. Reverse osmosis. Electrodialysis

Water

Credit

1
:

Water

Efficient

Landscaping

INTENT
:


Limit

or

eliminate

the

use

of

potable

water

for

landscape

irrigation
.

REQUIREMENT
:


Use

high

efficiency

irrigation

technology,

OR,

use

captured

rain

or

recycled

site

water

to

reduce

potable

water

consumption

for

irrigation

by

50
%

over

conventional

means
.



Use

only

captured

rain

or

recycled

site

water

for

an

additional

50
%

reduction

(
100
%

total

reduction)

of

potable

water

for

site

irrigation

needs,

OR,

do

not

install

permanent

landscape

irrigation

systems
.


THCHNOLOGIES/STRATHGIES
:


Develop

a

landscaping

water

use

baseline

according

to

the

methodology

outlined

in

the

LEED

Reference

Guide
.



Specify

water
-
efficient,

native

or

adapted,

climate

tolerant

planting
s
.



High

efficiency

irrigation

technologies

include

micro

irrigation
,

moisture

sensors
,

or

weather

data

based

controllers
.



Feed

irrigation

systems

with

captured

rainwater
,

gray

water
,

or

on
-
site

treated

wastewater

Micro
-
irrigation refers to low
-
pressure irrigation systems that
spray, mist, sprinkle or drip. The water discharge patterns differ
because emission devices are designed for specific applications due
to agronomic or horticultural requirements. Micro irrigation is
most useful and efficient for irrigation. It saves almost 70% water


Micro
-
irrigation

The controller operates based on soil moisture measured by moisture
sensors. Installing a irrigation system will typically result in water
savings of up to 40%.

moisture sensors

Weather

based

or

Smart

controllers

use

current

weather

conditions

instead

of

preset

times

to

accurately

water

the

landscape
.

Controllers

use

weather

data

which

comes

from

local

weather

stations

that

send

the

information

to

computers
.

Software

uses

this

data

to

calculate

an

ET(evapotranspiration)

value

and

sends

this

information

along

with

current

conditions

to

your

controller
.

The

controller

then

decides

if

the

system

should

water
.


weather data based controllers

http://images.google.cn/imgres?imgurl=http://www.weatherain.com/images/evaporate.gif&imgrefurl=http://www.weatherain.com/&h=2
02&
w=180&sz=7&hl=zh
-
CN&start=11&usg=__wthsj1FruMUJktR_euQ6YCMQF3A=&tbnid=Tkqq1a2R2P6Q8M:&tbnh=105&tbnw=94&prev=/images%3Fq%3Dweather%2Bdata%2
Bbased%2Birrigation%2Bcontrollers%26complete%3D1%26hl%3Dzh
-
CN%26newwindow%3D1%26sa%3DG

www.weatherain.com/


What is greywater?


Greywater is wastewater from bathtubs, showers,
bathroom sinks, washing machines, dishwashers and
kitchen sinks: any source in your home other than toilets.


It is important to understand that greywater can
contain harmful bacteria, viruses, and chemicals
that pose a risk to public health and the
environment if mishandled.

What’s in Greywater?

Greywater
Source

Characteristics*

Clothes Washer

Bacteria, bleach, foam, high pH, hot
water, nitrates, oil and grease, salinity,
soaps, sodium and suspended solids

Bathtub and Shower

Bacteria, hair, hot water, odor, oil and grease,
soaps,and suspended solids

Sinks

Bacteria, food particles, hot water, odor, oil and
grease,organic matter, soaps, and suspended
solids

* These characteristics make it necessary to properly treat greywater

Onsite (or decentralized) wastewater treatment systems are used to
treat wastewater from a home or business and return treated
wastewater back into the receiving environment. They are typically
referred to as
septic systems
, because most involve a
septic tank

for
partial treatment.


Onsite Wastewater Treatment Systems (OWTS)

The most common and traditional septic systems consist of a
septic
tank

that gravity flows to a soil adsorption field for final treatment
and dispersal. The septic tank allows particulate matter to settle to
the bottom of the tank so that large solids do not plug the drain field.
An effluent screen placed in the outlet of the septic tank is used to
filter suspended solids out of the effluent. Final treatment and
dispersal of the wastewater takes place in the soil adsorption filed.

Septic Tank

The septic tank is the most cost efficient method available to treat
residential wastewater. But for it to work properly, you need to
choose the right kind of septic tank for your household size and
soil type, and you need to maintain it regularly.

A septic tank is an enclosed watertight container that collects and
provides primary treatment of wastewater by separating solids
from the effluent. It removes the solids by slowing down the
wastewater flow in the tank and allowing the settleable solids to
settle to the bottom of the tank while the floatable solids (fats, oil,
and greases) rise to the top.

To provide time for the solids to settle,
detention time

should be at
least 24 hours.

Some of the solids are removed from the water, some are digested,
and some are stored in the tank. Up to 50 percent of the solids
retained in the tank decompose; the rest accumulate as sludge at
the tank bottom and need to be removed periodically by pumping
the tank. Tanks should be pumped by a licensed pumper every 5
-
7
years for most residential systems and inspected annually.

Soil Adsorption Field

A soil absorption field is a generic term for a final treatment and
dispersal component. It is also known as a drainfield, a soil treatment
area, and a leach field. They contain beds or trenches and can be
gravity
-
fed or pressure
-
dosed. They include a variety of different
technologies that distribute the wastewater into a variety of different
medias.





Effluent Screen

An effluent screen should be placed in the outlet of the septic
tank for additional filtration of the wastewater. Effluent
screens remove solids that could instead be carried out of the
tank and potentially clog downstream treatment devices. They
should be rinsed off biannually to remove the biological
growth that may inhibit flow out of the septic tank.


Final Treatment and Dispersal

Final treatment and dispersal components provide the final removal of
contaminants and distribute the effluent for dispersal back into the
environment. Several options are available for distributing wastewater in
soil. Gravity flow systems are the most widely used dispersal systems.
These systems will continue to be used in areas where the soil separation
distances can be met, primarily because they are the least expensive
alternative and require the least amount of operation and maintenance.

Pressurized distribution methods overcome a variety of site limitations.
Low pressure, subsurface drip, and spray distribution systems are
designed to function in difficult areas. These systems are pressurized,
which assists in providing even distribution of wastewater. These
technologies also facilitate reuse of wastewater in the landscape. These
advantages, however, increase the operation and maintenance
requirements.


Water

Credit

2
:

Innovative

Wastewater

Technologies

INTENT
:

Reduce

generation

of

wastewater

and

potable

water

demand,

while

increasing

local

recharge
.

REQUIREMENT
:

Reduce

the

use

of

municipally

provided

potable

water

for

building

sewage

conveyance

by

a

minimum

of

50
%
,

OR,

treat

100
%

of

wastewater

on

site

to

tertiary

standards
.


TECHNOLOGIES/STRATEGIES
:



Develop

a

wastewater

baseline

according

to

the

methodology

outlined

in

the

LEED

Reference

Guide
.



Implement

decentralized

on
-
site

wastewater

treatment

and

reuse

systems
.




Decrease

the

use

of

potable

water

for

sewage

conveyance

by

utilizing

gray

and/or

black

water

systems
.

Non
-
potable

reuse

opportunities

include,

toilet

flushing,

landscape

irrigation,

etc
.




Provide

advanced

wastewater

treatment

after

use

by

employing

innovative,

ecological,

on
-
site

technologies

including

constructed

wetlands
,

a

mechanical

recirculation

sand

filter
,

or

aerobic

treatment

units
.



A Constructed Wetland (CW) is a
man
-
made wetland created where
none has existed before, and which
purifies wastewater using natural
processes.


A CW purifies wastewater
the way nature does
-

without
electricity, chemicals or a large
technical workforce.





Constructed Wetland


Each CW is purpose
-
designed for its site, and the type
and capacity of treatment required.


The completed
wetland is an attractive working eco
-
system complete with
plants and trees, birds, fish and amphibian life.


The treated
water is returned safely to the environment for use by
others, or can be recycled for other uses.


A Constructed Wetland is emphatically NOT a soil
-
based adaption of any conventional wastewater treatment
system.

Constructed Wetland


Recirculating

sand

filters

were

developed

in

the

1970
's

and

found

to

produce

more

consistent

effluent

quality

with

reduced

filter

plugging
.

The

recirculating

filter

consists

of

a

recirculation

basin

where

the

incoming

wastewater

is

mixed

with

a

portion

of

the

filtered

effluent,

a

filter

bed

with

distribution

network,

underdrain

assembly,

and

a

storage

basin

for

the

treated

effluent

not

returned

to

the

recirculation

basin
.

Recirculating

filters

typically

produce

a

very

high

quality

effluent

and

can

provide

nitrogen

removal

if

configured

for

denitrification
.


recirculation sand filter

Aerobic

Treatment

Units

(ATUs)

are

similar

to

standard

septic

systems

in

that

they

use

natural

processes

to

treat

wastewater
.

But

unlike

conventional

systems,

ATUs

also

use

oxygen

to

break

down

organic

matter,

much

the

same

as

municipal

wastewater

treatment

systems,

but

in

a

scaled
-
down

version
.





Because

ATUs

decompose

organic

solids

quickly,

the

wastewater

leaving

the

system

is

cleaner
.

ATUs

are

useful

in

environmentally

sensitive

areas

or

locations

that

are

less

suitable

for

conventional

or

gravity

flow

septic

systems,

such

as

inappropriate

soil

conditions

where

the

water

table

is

too

high

to

allow

the

drainfield

to

operate

effectively
.



Aerobic Treatment Units (ATUs)



There are many types of ATUS, but the most common household ATUs
use a process called
suspended growth
. These units have a main
compartment (aeration chamber) in which air is forced and mixed with
the wastewater. This creates an environment where bacteria are free
-
floating in the liquid and grow as they digest the solids (suspended
growth).




How Does It Work?

Suspended
-
growth ATU



Many units include a second chamber where solids, that the
bacteria are unable to digest, settle. The two chambers are
connected, so these undigested solids can be returned to the
aeration chamber, either by gravity or a pump. It is this
process of return and mixing that is important for effective
operation.


Water

Credit

3
:

Water

Use

Reduction

INTENT
:


Maximize

water

efficiency

within

buildings

to

reduce

the

burden

on

municipal

water

supply

and

wastewater

systems
.

REQUMEMENT
:


Employ

strategies

that

in

aggregate

use

20
%

less

water

than

the

water

use

baseline

calculated

for

the

building

(not

including

irrigation)

after

meeting

Energy

Policy

Act

of

1992

fixture

performance

requirements
.



Exceed

the

potable

water

use

reduction

by

an

additional

10
%

(
30
%

total

efficiency

increase)
.


TECHNOLOGIES/STRATEGIES
:



Develop

a

water

use

baseline

including

all

water

consuming

fixtures,

equipment,

and

seasonal

conditions

according

to

methodology

guidance

outlined

in

the

LEED

Reference

Guide
.




Specify

water

conserving

plumbing

fixtures

that

exceed

Energy

Policy

Act

of

1992

fixture

requirements

in

combination

with

ultra

high

efficiency

or

dry

fixture

and

control

technologies
.








Specify

high

water

efficiency

equipment

(dishwashers,

laundry,

cooling

towers,

etc

.
)

.




Use

alternatives

to

potable

water

for

sewage

transport

water
.




Use

recycled

or

storm

water

for

HVAC/process

make

up

water
.

How to classify wastewater
-
treatment
methods?

Translate the following paragraph into
Chinese.

Develop

a

wastewater

baseline

according

to

the

methodology

outlined

in

the

LEED

Reference

Guide
.

Implement

decentralized

on
-
site

wastewater

treatment

and

reuse

systems
.

Decrease

the

use

of

potable

water

for

sewage

conveyance

by

utilizing

gray

and/or

black

water

systems
.

Non
-
potable

reuse

opportunities

include,

toilet

flushing,

landscape

irrigation,

etc
.

Provide

advanced

wastewater

treatment

after

use

by

employing

innovative,

ecological,

on
-
site

technologies

including

constructed

wetlands,

a

mechanical

recirculation

sand

filter,

or

aerobic

treatment

systems
.