2.water treatment Works

lyricalwillingMécanique

22 févr. 2014 (il y a 3 années et 5 mois)

64 vue(s)

1.


Physical process characteristics

We play logics here, physical process is a process involve solely based on physical properties of
the process to remove contaminants or pollutants without involvement of chemical substance or
microorganisms. Main signal
is the absence of structure and dimension of pollutants.

1. There is no change in shape of contaminanst

2. There is no involvement of biological and chemical process

Assignment

For this subject there are an assignment will be given to each group for both c
lass, A and B.

1. Make a post about physical process from various sources (internet, handbook, journals)

2. From the picture above, find which unit are employing physical process, describe your answer.

3. Find other technologies that employ physical proces
s. Describe them (if any)

4. Find the best location for those advanced technologies you mentioned above within the picture
(water and wastewater plant treatment) above and describe the reason.

Technical:

1. Max point is 10 for this assignment.

2. Post in t
he website min 500 words

2.


water treatment Works

Everythings come up from the source. We have to know the source of water that need to be
treated. There are various kinds of water source, it may come from river, like our PDAM
(Drinking Water Supply Company)

Surabaya uses, or lake, or groundwater, or sewage water.
Sewage water as well may be derived from Industry, municipal industry (home industry), or
residencial (houses). The implementation of sewerage in Indonesia for residencial is limited
to only several

cities incluse Nusa Dua Bali, Citraland Surabaya, Medan and Tangerang (I
will update this list). Since not all cities have been “equipped” with adequate wastewater
collection, thus the wastewater treatment may be said to be on focus in industrial wastewat
er
which we are most probably aware much more complex in terms of contaminants within
wastewater.

From the source, the water is taken by an intake. It depends on the installation, some intakes
are pre
-
equipped with screening before water flows inside the c
anal. So you have to be
careful whether you will place the screen before intake or at the canal intake. Several factors
may be considered such as the method used to take up water. If we use pump to suck the
water, the screen is probably better to be instal
led on the pump pipe, since this probably is
close channel.

Screening is physical separation for debris, coarse, grave contained within source water so
this is part of Unit Operations as well as intake. Prasedimentation is made to allow gravity
settling of

contaminants and pollutants due to their weight factor. Prasedimentation will be
covered later. In coagulation process, water is mixed with chemical agent such as alum or
ferric chloride to allow small organic particles to aggregate within them in a flocc
ulation
basin. Coagulation and flocculation are regarded as chemical process, although these two
processes may be taken into account for this course, the emphasize is not too weight.
Sedimentation is physical process, allowing aggregated particles from coa
gulation
-
flocculation to settle employing gravitation. Filter is also physical process, involves
adsorption acts as primary process to remove contaminants.

3. Screening, prasedimentation, sedimentation and
filtration
.

Coagulation is the type of chemical
process but the flocculation isn’t. Flocculation deploys the
aggregation within particles and let them to settle because of their weight. There is one unit is
actually can be covered, it is intake. Intake indeed does not cover any physical process instead
to
allow water to pass on next stage of water treatment.

Students have to comprehend the scheme at this stage, and the location where they will be taught
of the materials. There are several technologies, advanced one, may replace these conventional
unit su
ch as filtration is replaced by ultrafiltration so forth, this will be covered at later weeks.
Candidates for these advanced physical process are membrane technology, advanced adsorption
with others more advised from student.

20 MARKS ANSWER

1.BASIC PRINCI
PLES OF FOOD PROCESS ENGINEERING

The study of process engineering is an attempt to combine all forms of physical processing into a small
number of basic operations, which are called unit operations. Food processes may seem bewildering in
their diversity, b
ut careful analysis will show that these complicated and differing processes can be
broken down into a small number of unit operations. For example, consider heating of which innumerable
instances occur in every food industry. There are many reasons for he
ating and cooling
-

for example, the
baking of bread, the freezing of meat, the tempering of oils.


But in process engineering, the prime considerations are firstly, the extent of the heating or cooling that is
required and secondly, the conditions under w
hich this must be accomplished. Thus, this physical
process qualifies to be called a unit operation. It is called 'heat transfer'.


The essential concept is therefore to divide physical food processes into basic unit operations, each of
which stands alone
and depends on coherent physical principles. For example, heat transfer is a unit
operation and the fundamental physical principle underlying it is that heat energy will be transferred
spontaneously from hotter to colder bodies.

Because of the dependence o
f the unit operation on a physical principle, or a small group of associated
principles, quantitative relationships in the form of mathematical equations can be built to describe them.
The equations can be used to follow what is happening in the process, a
nd to control and modify the
process if required.


Important unit operations in the food industry are fluid flow, heat transfer, drying, evaporation, contact
equilibrium processes (which include distillation, extraction, gas absorption, crystallization, an
d
membrane processes), mechanical separations (which include filtration, centrifugation, sedimentation and
sieving), size reduction and mixing.


These unit operations, and in particular the basic principles on which they depend, are the subject of this
bo
ok, rather than the equipment used or the materials being processed.


Two very important laws which all unit operations obey are the laws of conservation of mass and energy.


2.Conservation of Mass and Energy

The law of conservation of mass states that
mass can neither be created nor destroyed. Thus in a
processing plant, the total mass of material entering the plant must equal the total mass of material
leaving the plant, less any accumulation left in the plant. If there is no accumulation, then the sim
ple rule
holds that "what goes in must come out". Similarly all material entering a unit operation must in due
course leave.


For example, if milk is being fed into a centrifuge to separate it into skim milk and cream, under the law of
conservation of mass

the total number of kilograms of material (milk) entering the centrifuge per minute
must equal the total number of kilograms of material (skim milk and cream) that leave the centrifuge per
minute.


Similarly, the law of conservation of mass applies to eac
h component in the entering materials. For
example, considering the butter fat in the milk entering the centrifuge, the weight of butter fat entering the
centrifuge per minute must be equal to the weight of butter fat leaving the centrifuge per minute. A s
imilar
relationship will hold for the other components, proteins, milk sugars and so on.


The law of conservation of energy states that energy can neither be created nor destroyed. The total
energy in the materials entering the processing plant, plus the e
nergy added in the plant, must equal the
total energy leaving the plant.


This is a more complex concept than the conservation of mass, as energy can take various forms such as
kinetic energy, potential energy, heat energy, chemical energy, electrical ene
rgy and so on.

During processing, some of these forms of energy can be converted from one to another. Mechanical
energy in a fluid can be converted through friction into heat energy. Chemical energy in food is converted
by the human body into mechanical e
nergy.


Note

that it is the sum total of all these forms of energy that is conserved.


For example, consider the pasteurizing process for milk, in which milk is pumped through a heat
exchanger and is first heated and then cooled. The energy can be conside
red either over the whole plant
or only as it affects the milk. For total plant energy, the balance must include: the conversion in the pump
of electrical energy to kinetic and heat energy, the kinetic and potential energies of the milk entering and
leavin
g the plant and the various kinds of energy in the heating and cooling sections,as well as the exiting
heat, kinetic and potential energies.

To the food technologist, the energies affecting the product are the most important. In the case of the
pasteurizer
, the energy affecting the product is the heat energy in the milk. Heat energy is added to the
milk by the pump and by the hot water passing through the heat exchanger. Cooling water then removes
part of the heat energy and some of the heat energy is also
lost to the surroundings.


The heat energy leaving in the milk must equal the heat energy in the milk entering the pasteurizer plus or
minus any heat added or taken away in the plant.

Heat energy leaving in milk = initial heat energy











































+ heat energy added by pump











































+ heat energy added in heating section











































-

heat energy taken out in cooling section











































-

heat energy lost to surroundings.

The law of conservation of energy can also apply to part of a process. For example, considering the
heating section of the heat exchanger in the pasteurizer, the heat lost by the hot water must b
e equal to
the sum of the heat gained by the milk and the heat lost from the heat exchanger to its surroundings.


From these laws of conservation of mass and energy, a balance sheet for materials and for energy can
be drawn up at all times for a unit opera
tion. These are called material balances and energy balances.

Overall View of an Engineering Process

Using a material balance and an energy balance, a food engineering process can be viewed overall or as
a series of units. Each unit is a unit operation. Th
e unit operation can be represented by a box as shown
in
Fig. 1.1
.


Fig. 1.1

Unit operation

Into the box go the raw materials and energy, out of the box come the desired products, by
-
products,
wastes and energy. The equipment within the box will enable t
he required changes to be made with as
little waste of materials and energy as possible. In other words, the desired products are required to be
maximized and the undesired by
-
products and wastes minimized. Control over the process is exercised
by regulati
ng the flow of energy, or of materials, or of both.




3.
The
Networking Model
OSI

The Open System Interconnection (OSI) model, developed by the International Organization for
Standardization, defines how the various hardware and software components involved in data
communication should interact with each other.

A good analogy would be
a traveler who prepares herself to return home through many
dangerous kingdoms by obtaining permits to enter each country at the very beginning of the trip.
At each frontier our friend has to hand over a permit to enter the country. Once inside, she asks
t
he border guards for directions to reach the next frontier and displays the permit for that new
kingdom as proof that she has a legitimate reason for wanting to go there.

In the OSI model each component along the data communications path is assigned a lay
er of
responsibility, in other words, a kingdom over which it rules. Each layer extracts the permit, or
header information, it needs from the data and uses this information to correctly forward what's
left to the next layer. This layer also strips away its

permit and forwards the data to the next
layer, and so the cycle continues for seven layers.

The very first layer of the OSI model describes the transmission attributes of the cabling or
wireless frequencies used at each "link" or step along the way. Lay
er 2 describes the error
correction methodologies to be used on the link; layer 3 ensures that the data can hop from link
to link on the way to the final destination described in its header. When the data finally arrives,
the layer 4 header is used to dete
rmine which locally installed software application should
receive it. The application uses the guidelines of layer 5 to keep track of the various
communications sessions it has with remote computers and uses layer 6 to verify that the
communication or file

format is correct. Finally, layer 7 defines what the end user will see in the
form of an interface, be it graphical on a screen or otherwise. A description of the functions of
each layer in the model can be seen in Table 2
-
1.

Installing the Linux operati
ng system is only the first step toward creating a fully functional
departmental server or Web site. Almost all computers are now networked in some way to other
devices therefore a basic understanding of networking and issues related to the topic will be
e
ssential to feeling comfortable with Linux servers.

This introductory chapter forms the foundation on which the following network configuration
and troubleshooting chapters will be built. These chapters will then introduce the remaining
chapters that cove
r Linux troubleshooting, general software installation and the configuration of
many of the most popular Linux applications used in corporate departments and Small
Office/Home Office (SOHO) environments.

Familiarity with the concepts explained in the foll
owing sections will help answer many of the
daily questions often posed by coworkers, friends, and even yourself. It will help make the road
to Linux mastery less perilous, a road that begins with an understanding of the OSI networking
model and TCP/IP.

4.
Sources of a Lack of Connectivity

All sources of slowness can become so severe that connectivity is lost. Additional sources of
disconnections are:



Power failures



The remote server or an application on the remote server being shut down.

We discuss how
to isolate these problems and more in the following sections.

Doing Basic Cable and Link Tests

Your server won't be able to communicate with any other device on your network unless the
NIC's "link" light is on. This indicates that the connection between your server and the
switch/router is functioning correctly.

In most cases a lack of link is due
to the wrong cable type being used. As described in Chapter 2,
"
Introduction to Networkin
g
", there are two types of Ethernet cables crossover and straight
-
through. Always make sure you are using the correct type.

Other sources of link failure include:



The cables are bad.



The switch or router to which the server is connected is powered down.




The cables aren't plugged in properly.

If you have an extensive network, investment in a battery
-
operated cable tester for basic
connectivity testing is invaluable. More sophisticated models in the market will be able to tell
you the approximate locatio
n of a cable break and whether an Ethernet cable is too long to be
used.

Sources of Network Slowness



NIC duplex and speed incompatibilities



Network congestion



Poor routing



Bad cabling



Electrical interference



An overloaded server at the remote end of

the connection



Misconfigured DNS (Covered in Chapter 18, "
Configuring DNS
" and Chapter 19, "
Dynamic DNS
")