CHAPTER ONE

INTRODUCTION

1.0 BACKGROUND OF STUDY

Water treatment is collectively the local and

industrial-scale processes that remove contaminants

from untreated make it more acceptable for an end-

use, which may be human consumption, industry or

medicine. Water treatment should remove existing

water contaminant or to reduce their concentration

that the water become fit for its desired end-use,

which may be safely returning used water to the

environment.

The lack of access to safe water and adequate

sanitation is at the core of the main symptoms and

causes of world poverty, reinforcing the cycle of

poverty and incapacity that keeps people trapped and

slows the development of societies. Inadequate access

to safe water can cause people’s health to suffer,

especially children, ranging from reduced growth and

life expectancy to critical bouts of diseases, often

leading to death.

Contamination of drinking water sources by disease

causing microbial agents and chemical toxicants such 1

as pesticides, pharmaceuticals, industrial wastes and

fuel components is a growing worldwide problem.

Microbiological water contaminants cause diarrhoea,

flu and other diseases. Many synthetic chemical

contaminants bio-accumulate in the human body and

cause cancer, birth defects and diseases of the

reproductive system, and disrupt endocrine and

neurological systems. Due to the increased water

requirement and unavailability of portable water the

treatment plant is required both locally and

industrially at low cost.

For households and communities in remote areas, low-

cost decentralized water treatment for removal of

biological and chemical contaminants can be

accomplished using filter media generated/acquired

locally.

1.1 OBJECTIVE OF STUDYFor most people, the term “water treatment” refers to

portable water production from raw water, whereas

“wastewater treatment” refers to the treatment of

polluted water, where the pollution could be from

human waste, industry, agriculture waste or other

2

sources of pollution. This paper presents the design

of portable water treatment plant for safe drinking.

1.2 SCOPE OF STUDY Sitting for both industrial and home treatment

plant design

Drilling of bore hole

Setting of sand and carbon bed filter

Installation and working principle of reverse

osmosis system

Piping(PVC) of equipments

Fixing of cartridges

1.3 JUSTIFICATION OF STUDYWater is a vital requirement of human for everyday

living, impurities and toxic substances retard the

normal function (metabolism i.e catabolism and

anabolism) of the body. This work shows water

treatment plant design which will enable the

production of safe drinking water.

3

CHAPTER TWO

LITERATURE REVIEW

2.1 WATERWater is a transparent fluid which forms lakes,

streams, ocean and rain. Water contains one molecule

of oxygen and two molecules of hydrogen that are

connected by covalent bonds. Water covers about 71%

of the earth’s surface and of the mass of the body.

It is vital for all forms of life (Wikipedia ed.).

2.1.1 CHEMICAL AND PHYSICAL PROPERTIES OF WATERChemically, water is a compound of hydrogen and

oxygen, having the formula H2O. It is chemically

active, reacting with certain metals and metal oxides

to form bases, and with certain oxides of non-metals

to form acids. It reacts with certain organic

compounds to form a variety of products. Because

water is a polar compound, it is a good solvent.

Although pure water is a poor conductor of

electricity, it is a much better conductor than most

4

other pure liquids because of self ionization i.e.,

the ability of two water molecules to react to form a

hydroxide ion, OH-, and a hydronium ion, H3O+. Its

polarity and ionization are both due to the high

dielectric constant of water. Physically, pure water

is colourless, odourless and tasteless. Solid water

floats on liquid water. As water cools, it contracts

until it reaches 4oC, then it expands until it freezes

at 0OC (Prof Shakhashiri January 2011).

2.2 SOURCES OF WATER

Water is also found below the earth surface and in

the atmosphere in the form of water vapour.

Rainwater, ocean, rivers, lakes, streams, ponds and

springs are natural sources of water. Dams, wells,

tube wells, hand-pumps, canals, e.t.c are man-made

sources of water.

Rain Water : Rain water collects on the earth in the

form of surface water and underground water.

Surface Water: Water present on the surface of the

earth in a form of oceans, rivers, lakes, ponds and

streams is called surface water. The water in rivers

and lakes comes from rain and melting of snow on

mountains. Rivers flow into sea.

5

Underground Water: Some of the rain water seeps

through the soil to the non-porous rocks below.

Sometimes due to high pressure, this water sprouts

out in the form of springs. It can be obtained by

digging wells, sinking tube wells (borehole).

2.3 List of Contaminants and Their Maximum

Contaminant Levels (MCLS)

An alphabetical listing with links to fact sheets on

the primary drinking water regulations.

Microorganisms

Disinfectants

Disinfection By-products

Inorganic Chemicals

Organic Chemicals

Radionuclides

Contamina

nt

MCLG(MG/

L)

MCLor TT(MG

/L)

Potential

Health

Effects

from

Long-Term

Exposure

Above

the MCL (

Sources

of

Contamin

ant in

Drinking

Water

6

unless

specified

as short-

term)Cryptosporid

ium

Zero TT Gastroint

estinal

illness

(such as

diarrhea,

vomiting,

and

cramps)

Human

and

animal

fecal

waste

Giardia

lamblia

Zero TT Gastroint

estinal

illness

(such as

diarrhea,

vomiting,

and

cramps)

Human

and

animal

fecal

waste

Heterotro

phic

plate

n/a TT HPC has

no health

effects;

HPC meas

ures a

range of

7

count

(HPC)

it is an

analytic

method

used to

measure

the

variety

of

bacteria

that are

common in

water.

The lower

the

concentra

tion of

bacteria

in

drinking

water,

the

better

maintaine

d the

bacteria

that are

naturall

y

present

in the

environm

ent

8

water

system

is.

Legionella Zero TT Legionnai

re's

Disease,

a type of

pneumonia

Found

naturall

y in

water;

multipli

es in

heating

systems

Total

Coliforms

(includin

g fecal

coliform

and E. Coli)

Zero 5.0% Not a

health

threat in

itself;

it is

used to

indicate

whether

other

potential

ly

harmful

Coliform

s are

naturall

y

present

in the

environm

ent; as

well as

feces;

fecal

coliform

9

bacteria

may be

present5

s and E.

coli only

come

from

human

and

animal

fecal

waste.

Turbidity n/a TT Turbidity

is a

measure

of the

cloudines

s of

water. It

is used

to

indicate

water

quality

and

filtratio

n

Soil

runoff

10

effective

ness

(such as

whether

disease-

causing

organisms

are

present).

Higher

turbidity

levels

are often

associate

d with

higher

levels of

disease-

causing

microorga

nisms

such as

viruses,

parasites

11

and some

bacteria.

These

organisms

can cause

symptoms

such as

nausea,

cramps,

diarrhea,

and

associate

d

headaches

.

Viruses

(enteric)

Zero TT Gastroint

estinal

illness

(such as

diarrhea,

vomiting,

and

cramps)

Human

and

animal

fecal

waste

12

Disinfection By-products

Contaminant MCLG

(MG/

L)

MCL or

TT(MG/L

)

Potential

Health

Effects from

Long-Term

Exposure

Above

the MCL (unle

ss specified

as short-

term)

Sources

of

Contamina

nt in

Drinking

Water

Bromate Zero 0.010 Increased

risk of

cancer

By-

product

of

drinking

water

disinfect

ion

Chlorite 0.8 1.0 Anaemia;

infants and

young

children:

Byproduct

of

drinking

water

13

nervous

system

effects

disinfect

ion

Halo acetic

acids

(HAA5)

n/a 0.060 Increased

risk of

cancer

Byproduct

of

drinking

water

disinfect

ion

Total

Trihalometh

anes

(TTHMS)

n/a -->

0.080

Liver, kidney

or central

nervous

system

problems;

increased

risk of

cancer

Byproduct

of

drinking

water

disinfect

ion

Disinfectants

Contamina

nt

MCLG

(MG/L)

MCL or T

T

Potential

Health

Effects

Sources

of

Contamina14

(MG/L) from Long-

Term

Exposure

Above

the MCL (un

less

specified

as short-

term)

nt in

Drinking

Water

Chloramin

es (CL2)

MRDLG=4 MRDL=4.0 Eye/nose

irritation;

stomach

discomfort,

anemia

Water

additive

used to

control

microbes

Chlorine

( CL2)

MRDLG=4 MRDL=4.0 Eye/nose

irritation;

stomach

discomfort

Water

additive

used to

control

microbes

Chlorine

dioxide

(CLO2)

MRDLG=0.

8

MRDL=0.8 Anemia;

infants and

young

children:

Water

additive

used to

control

15

nervous

system

effects

microbes

Inorganic Chemicals

Contamina

nt

MCLG

(MG/

L)

MCL or T

T

(MG/L)

Potential

Health

Effects

from Long-

Term

Exposure

Above

the MCL (un

less

specified

as short-

term)

Sources of

Contaminant

in Drinking

Water

Antimony 0.00

6

0.006 Increase in

blood

cholesterol

; decrease

in blood

sugar

Discharge

from

petroleum

refineries;

fire

retardants;

16

ceramics;

electronics;

solder

Arsenic 0 0.010 as

of

01/23/06

Skin damage

or problems

with

circulatory

systems,

and may

have

increased

risk of

getting

cancer

Erosion of

natural

deposits;

runoff from

orchards,

runoff from

glass and

electronicspr

oduction

wastes

Asbestos

(fiber >

10

micromete

rs)

7

mill

ion

fibe

rs

per

lite

r

(MFL

7 MFL Increased

risk of

developing

benign

intestinal

polyps

Decay of

asbestos

cement in

water mains;

erosion of

natural

deposits

17

)Barium 2 2 Increase in

blood

pressure

Discharge of

drilling

wastes;

discharge

from metal

refineries;

erosion of

natural

deposits

Beryllium 0.00

4

0.004 Intestinal

lesions

Discharge

from metal

refineries

and coal-

burning

factories;

discharge

from

electrical,

aerospace,

and defense

industries

Cadmium 0.00 0.005 Kidney Corrosion of

18

5 damage galvanized

pipes;

erosion of

natural

deposits;

discharge

from metal

refineries;

runoff from

waste

batteries and

paints

Chromium

(total)

0.1 0.1 Allergic

dermatitis

Discharge

from steel

and pulp

mills;

erosion of

natural

deposits

Copper 1.3 TT;

Action

Level=1.

3

Short term

exposure:

Gastrointes

tinal

Corrosion of

household

plumbing

systems;

19

distress

Long term

exposure:

Liver or

kidney

damage

People with

Wilson's

Disease

should

consult

their

personal

doctor if

the amount

of copper

in their

water

exceeds the

action

level

erosion of

natural

deposits

Cyanide 0.2 0.2 Nerve Discharge

20

(as free

cyanide)

damage or

thyroid

problems

from

steel/metal

factories;

discharge

from plastic

and

fertilizer

factories

Fluoride 4.0 4.0 Bone

disease

(pain and

tenderness

of the

bones);

Children

may get

mottled

teeth

Water

additive

which

promotes

strong teeth;

erosion of

natural

deposits;

discharge

from

fertilizer

and aluminum

factories

Lead zero TT;

Action

Infants and

children:

Corrosion of

household

21

Level=0.

015

Delays in

physical or

mental

development

; children

could show

slight

deficits in

attention

span and

learning

abilities

Adults:

Kidney

problems;

high blood

pressure

plumbing

systems;

erosion of

natural

deposits

Mercury

(inorgani

c)

0.00

2

0.002 Kidney

damage

Erosion of

natural

deposits;

discharge

from

refineries

22

and

factories;

runoff from

landfills and

croplands

Nitrate

(measured

as

Nitrogen)

10 10 Infants

below the

age of six

months who

drink water

containing

nitrate in

excess of

the MCL

could

become

seriously

ill and, if

untreated,

may die.

Symptoms

include

shortness

of breath

Runoff from

fertilizer

use; leaking

from septic

tanks,

sewage;

erosion of

natural

deposits

23

and blue-

baby

syndrome.

Nitrite

(measured

as

Nitrogen)

1 1 Infants

below the

age of six

months who

drink water

containing

nitrite in

excess of

the MCL

could

become

seriously

ill and, if

untreated,

may die.

Symptoms

include

shortness

of breath

and blue-

baby

Runoff from

fertilizer

use; leaking

from septic

tanks,

sewage;

erosion of

natural

deposits

24

syndrome.

Selenium 0.05 0.05 Hair or

fingernail

loss;

numbness in

fingers or

toes;

circulatory

problems

Discharge

from

petroleum

refineries;

erosion of

natural

deposits;

discharge

from mines

Thallium 0.00

05

0.002 Hair loss;

changes in

blood;

kidney,

intestine,

or liver

problems

Leaching from

ore-

processing

sites;

discharge

from

electronics,

glass, and

drug

factories

25

Organic Chemicals

Contaminant MCLG

(MG/

L)

MCL or 

TT

(MG/L)

Potential

Health

Effects

from

Long-Term

Exposure

Above

the MCL(u

nless

specified

as short-

term)

Sources of

Contaminan

t in

Drinking

Water

Acrylamide Zero TT Nervous

system or

blood

problems;

increased

risk of

cancer

Added to

water

during

sewage/was

tewater

treatment

Alachlor Zero 0.002 Eye,

liver,

Runoff

from

26

kidney or

spleen

problems;

anemia;

increased

risk of

cancer

herbicide

used on

row crops

Atrazine 0.00

3

0.003 Cardiovas

cular

system or

reproduct

ive

problems

Runoff

from

herbicide

used on

row crops

Benzene Zero 0.005 Anemia;

decrease

in blood

platelets

;

increased

risk of

cancer

Discharge

from

factories;

leaching

from gas

storage

tanks and

landfills

Benzo(a)pyrene zero 0.0002 Reproduct Leaching

27

(PAHs) ive

difficult

ies;

increased

risk of

cancer

from

linings of

water

storage

tanks and

distributi

on lines

Carbofuran 0.04 0.04 Problems

with

blood,

nervous

system,

or

reproduct

ive

system

Leaching

of soil

fumigant

used on

rice and

alfalfa

Carbon

tetrachloride

Zero 0.005 Liver

problems;

increased

risk of

cancer

Discharge

from

chemical

plants and

other

industrial

28

activities

Chlordane Zero 0.002 Liver or

nervous

system

problems;

increased

risk of

cancer

Residue of

banned

termiticid

e

Chlorobenzene 0.1 0.1 Liver or

kidney

problems

Discharge

from

chemical

and

agricultur

al

chemical

factories

2,4-D 0.07 0.07 Kidney,

liver, or

adrenal

gland

problems

Runoff

from

herbicide

used on

row crops

Dalapon 0.2 0.2 Minor Runoff

29

kidney

changes

from

herbicide

used on

rights of

way

1,2-Dibromo-3-

chloropropane

(DBCP)

zero 0.0002 Reproduct

ive

difficult

ies;

increased

risk of

cancer

Runoff/

leaching

from soil

fumigant

used on

soybeans,

cotton,

pineapples

, and

orchards

o-

Dichlorobenzene

0.6 0.6 Liver,

kidney,

or

circulato

ry system

problems

Discharge

from

industrial

chemical

factories

p- 0.07 0.075 Anemia; Discharge

30

Dichlorobenzene 5 liver,

kidney or

spleen

damage;

changes

in blood

from

industrial

chemical

factories

1,2-

Dichloroethane

Zero 0.005 Increased

risk of

cancer

Discharge

from

industrial

chemical

factories

1,1-

Dichloroethylen

e

0.00

7

0.007 Liver

problems

Discharge

from

industrial

chemical

factories

cis-1,2-

Dichloroethylen

e

0.07 0.07 Liver

problems

Discharge

from

industrial

chemical

factories

trans-1,2- 0.1 0.1 Liver Discharge

31

Dichloroethylen

e

problems from

industrial

chemical

factories

Dichloromethane Zero 0.005 Liver

problems;

increased

risk of

cancer

Discharge

from drug

and

chemical

factories

1,2-

Dichloropropane

zero 0.005 Increased

risk of

cancer

Discharge

from

industrial

chemical

factories

Di(2-

ethylhexyl)

adipate

0.4 0.4 Weight

loss,

liver

problems,

or

possible

reproduct

ive

Discharge

from

chemical

factories

32

difficult

ies.

Di(2-

ethylhexyl)

phthalate

Zero 0.006 Reproduct

ive

difficult

ies;

liver

problems;

increased

risk of

cancer

Discharge

from

rubber and

chemical

factories

Dinoseb 0.00

7

0.007 Reproduct

ive

difficult

ies

Runoff

from

herbicide

used on

soybeans

and

vegetables

Dioxin

(2,3,7,8-TCDD)

Zero 0.00000

003

Reproduct

ive

difficult

ies;

Emissions

from waste

incinerati

on and

33

increased

risk of

cancer

other

combustion

;

discharge

from

chemical

factories

Diquat 0.02 0.02 Cataracts Runoff

from

herbicide

use

Endothall 0.1 0.1 Stomach

and

intestina

l

problems

Runoff

from

herbicide

use

Endrin 0.00

2

0.002 Liver

problems

Residue of

banned

insecticid

e

Epichlorohydrin Zero TT Increased

cancer

Discharge

from

34

risk, and

over a

long

period of

time,

stomach

problems

industrial

chemical

factories;

an

impurity

of some

water

treatment

chemicals

Ethylbenzene 0.7 0.7 Liver or

kidneys

problems

Discharge

from

petroleum

refineries

Ethylene

dibromide

Zero 0.00005 Problems

with

liver,

stomach,

reproduct

ive

system,

or

kidneys;

increased

Discharge

from

petroleum

refineries

35

risk of

cancer

Glyphosate 0.7 0.7 Kidney

problems;

reproduct

ive

difficult

ies

Runoff

from

herbicide

use

Heptachlor Zero 0.0004 Liver

damage;

increased

risk of

cancer

Residue of

banned

termiticid

e

Heptachlor

epoxide

Zero 0.0002 Liver

damage;

increased

risk of

cancer

Breakdown

of

heptachlor

Hexachlorobenze

ne

zero 0.001 Liver or

kidney

problems;

reproduct

Discharge

from metal

refineries

and

36

ive

difficult

ies;

increased

risk of

cancer

agricultur

al

chemical

factories

Hexachlorocyclo

pentadiene

0.05 0.05 Kidney or

stomach

problems

Discharge

from

chemical

factories

Lindane 0.00

02

0.0002 Liver or

kidney

problems

Runoff/

leaching

from

insecticid

e used on

cattle,

lumber,

gardens

Methoxychlor 0.04 0.04 Reproduct

ive

difficult

ies

Runoff/

leaching

from

insecticid

37

e used on

fruits,

vegetables

, alfalfa,

livestock

Oxamyl (Vydate) 0.2 0.2 Slight

nervous

system

effects

Runoff/

leaching

from

insecticid

e used on

apples,

potatoes,

and

tomatoes

Polychlorinated

biphenyls

(PCBS)

Zero 0.0005 Skin

changes;

thymus

gland

problems;

immune

deficienc

ies;

reproduct

Runoff

from

landfills;

discharge

of waste

chemicals

38

ive or

nervous

system

difficult

ies;

increased

risk of

cancer

Pentachlorophen

ol

Zero 0.001 Liver or

kidney

problems;

increased

cancer

risk

Discharge

from wood

preserving

factories

Picloram 0.5 0.5 Liver

problems

Herbicide

runoff

Simazine 0.00

4

0.004 Problems

with

blood

Herbicide

runoff

Styrene 0.1 0.1 Liver,

kidney,

or

Discharge

from

rubber and

39

circulato

ry system

problems

plastic

factories;

leaching

from

landfills

Tetrachloroethy

lene

Zero 0.005 Liver

problems;

increased

risk of

cancer

Discharge

from

factories

and dry

cleaners

Toluene 1 1 Nervous

system,

kidney,

or liver

problems

Discharge

from

petroleum

factories

Toxaphene Zero 0.003 Kidney,

liver, or

thyroid

problems;

increased

risk of

cancer

Runoff/

leaching

from

insecticid

e used on

cotton and

cattle

40

2,4,5-TP

(Silvex)

0.05 0.05 Liver

problems

Residue of

banned

herbicide

1,2,4-

Trichlorobenzen

e

0.07 0.07 Changes

in

adrenal

glands

Discharge

from

textile

finishing

factories

1,1,1-

Trichloroethane

0.20 0.2 Liver,

nervous

system,

or

circulato

ry

problems

Discharge

from metal

degreasing

sites and

other

factories

1,1,2-

Trichloroethane

0.00

3

0.005 Liver,

kidney,

or immune

system

problems

Discharge

from

industrial

chemical

factories

Trichloroethyle

ne

Zero 0.005 Liver

problems;

Discharge

from metal

41

increased

risk of

cancer

degreasing

sites and

other

factories

Vinyl chloride Zero 0.002 Increased

risk of

cancer

Leaching

from PVC

pipes;

discharge

from

plastic

factories

Xylenes (total) 10 10 Nervous

system

damage

Discharge

from

petroleum

factories;

discharge

from

chemical

factories

42

Radionuclides

Contamina

nt

MCLG

(MG/L

)

MCL orTT

(MG/L)

Potential

Health

Effects from

Long-Term

Exposure

Above

theMCL (unle

ss specified

as short-

term)

Sources of

Contaminant

in Drinking

Water

Alpha

particles

none-

-----

----

zero

15

picocuri

es per

Liter

(PCI/L)

Increased

risk of

cancer

Erosion of

natural

deposits of

certain

minerals

that are

radioactive

and may

emit a form

of

radiation

known as

alpha

43

radiation

Beta

particles

and

photon

emitters

none-

-----

----

zero

4

millirem

s per

year

Increased

risk of

cancer

Decay of

natural and

man-made

deposits of

certain

minerals

that are

radioactive

and may

emit forms

of

radiation

known as

photons and

beta

radiation

Radium

226 and

Radium

228

(combined

none-

-----

----

zero

5 PCI/L Increased

risk of

cancer

Erosion of

natural

deposits

44

)Uranium Zero 30 UG/

Las of

12/08/03

Increased

risk of

cancer,

kidney

toxicity

Erosion of

natural

deposits

Notes

 Definitions:

Maximum Contaminant Level Goal (MCLG) - The

level of a contaminant in drinking water below

which there is no known or expected risk to

health. MCLGs allow for a margin of safety and

are non-enforceable public health goals.

Maximum Contaminant Level (MCL) - The highest

level of a contaminant that is allowed in

drinking water. MCLs are set as close to MCLGs

as feasible using the best available treatment

technology and taking cost into consideration.

MCLs are enforceable standards.

Maximum Residual Disinfectant Level Goal (MRDLG)

- The level of a drinking water disinfectant

below which there is no known or expected risk 45

to health. MRDLGS do not reflect the benefits of

the use of disinfectants to control microbial

contaminants.)

Treatment Technique (TT) - A required process

intended to reduce the level of a contaminant in

drinking water.

Maximum Residual Disinfectant Level (MRDL) - The

highest level of a disinfectant allowed in

drinking water. There is convincing evidence

that addition of a disinfectant is necessary for

control of microbial contaminants.

 Units are in milligrams per liter (MG/L) unless

otherwise noted. Milligrams per liter are

equivalent to parts per million (PPM).

 EPA's surface water treatment rules require

systems using surface water or ground water

under the direct influence of surface water to

(1) disinfect their water, and

(2) Filter their water or meet criteria

for avoiding filtration so that the

following contaminants are controlled at

the following levels:

Cryptosporidium: Unfiltered systems are

required to include Cryptosporidium in 46

their existing watershed control

provisions

Giardia lamblia: 99.9%

removal/inactivation.

Viruses: 99.99% removal/inactivation.

Legionella: No limit, but EPA believes

that if Giardia and viruses are

removed/inactivated, according to the

treatment techniques in the Surface

Water Treatment Rule, Legionella will

also be controlled.   

Turbidity: For systems that use

conventional or direct filtration, at

no time can turbidity (cloudiness of

water) go higher than 1 Nephelometric

Turbidity Unit (NTU), and samples for

turbidity must be less than or equal to

0.3 NTUS in at least 95 percent of the

samples in any month. Systems that use

filtration other than the conventional

or direct filtration must follow state

limits, which must include turbidity at

no time exceeding 5 NTUS.

47

Heterotrophic Plate Count (HPC): No

more than 500 bacterial colonies per

milliliter.

Long Term 1 Enhanced Surface Water

Treatment: Surface water systems or

groundwater under the direct influence

(GWUDI) systems serving fewer than

10,000 people must comply with the

applicable Long Term 1 Enhanced Surface

Water Treatment Rule provisions (such

as turbidity standards, individual

filter monitoring, Cryptosporidium removal

requirements, updated watershed control

requirements for unfiltered systems).

Long Term 2 Enhanced Surface Water

Treatment Rule: This rule applies to

all surface water systems or ground

water systems under the direct

influence of surface water. The rule

targets

additionalCryptosporidium treatment

requirements for higher risk systems

and includes provisions to reduce risks

from uncovered finished water storage

48

facilities and to ensure that the

systems maintain microbial protection

as they take steps to reduce the

formation of disinfection by-products.

Filter Backwash Recycling: The Filter

Backwash Recycling Rule requires

systems that recycle to return specific

recycle flows through all processes of

the system's existing conventional or

direct filtration system or at an

alternate location approved by the

state.

No more than 5.0% samples total coliform-

positive (TC-POSITIVE) in a month. (For water

systems that collect fewer than 40 routine

samples per month, no more than one sample can

be total coliform-positive per month.) Every

sample that has total coliform must be analyzed

for either fecal coliforms or E. coli if two

consecutive TC-POSITIVE samples, and one is also

positive for E.coli fecal coliforms, system has an

acute MCL violation.

 Fecal coliform and E. coli are bacteria whose

presence indicates that the water may be

49

contaminated with human or animal wastes.

Disease-causing microbes (pathogens) in these

wastes can cause diarrhea, cramps, nausea,

headaches, or other symptoms. These pathogens

may pose a special health risk for infants,

young children, and people with severely

compromised immune systems.

Although there is no collective MCLG for this

contaminant group, there are

individual  MCLGS for some of the individual

contaminants:

Trihalomethanes: bromodichloromethane

(zero); bromoform (zero);

dibromochloromethane (0.06 MG/L):

chloroform (0.07 MG/L.

Haloacetic acids: dichloroacetic acid

(zero); trichloroacetic acid (0.02 MG/L);

monochloroacetic acid (0.07MG/L).

Bromoacetic acid and dibromoacetic acid

are regulated with this group but have no

MCLGs.

 Lead and copper are regulated by a treatment

technique that requires systems to control the

corrosiveness of their water. If more than 10% 50

of tap water samples exceed the action level,

water systems must take additional steps. For

copper, the action level is 1.3 MG/L, and for

lead is 0.015 MG/L.

 Each water system must certify, in writing, to

the state (using third-party or manufacturer's

certification) that when acrylamide and

epichlorohydrin are used to treat water, the

combination (or product) of dose and monomer

level does not exceed the levels specified, as

follows:

Acrylamide = 0.05% dosed at 1 MG/L (or

equivalent)

CHAPTER THREEEQUIPMENT AND DESIGN METHODOLOGY

3.1 SITTING AND MATERIAL 3.1.1 SITTING

Gravity is the easiest and most dependable way to

move water. The water system should be sited on

stable, level ground, and at lower elevation than the

source water and higher elevation than the

location(s) where treated water will be used. This

51

circumstance enables completely passive operation of

the treatment system and very simple control using

only a float valve (the same device that refills the

tanks of flush toilets): when water is withdrawn from

the storage tank the water level in the system drops,

opening the float valve. When the system is full, the

float valve closes. Plumbing connections should be

protected from accidental damage, and the entire

system should be shaded to prevent degradation of

plastic components by sunlight.

3.1.2 CONTAINMENT AND PLUMBING

The following parts and tools are required for

water system installation.

a) PLUMBING PIPES AND OTHERS

This involve the PVC pipes fitting and their

measurement used for connecting the water system to

existing water supply and point-of-use

infrastructure, as well as a number of recommended

spares. Tools required include a sharp pocketknife

and serrated blade for cutting PVC, a tape measure,

paintbrush for applying silicon and PVC glue, and a

permanent marker.

Plumbing part summary Total quantity

52

Hoseclamp 12Hosebarb 12¾’’ valve and 3/4” T 2 each¾” female coupler 25000L HPDE Drum 4½” (male and female

coupler)

8 and 19

½”(end cap and elbow) 3 and 6½”-3/4” coupler 3 1-1/2” or 2” male end screw

cap

1

1-2 male coupler 1

1-1/2” or 2” female

coupler

2

OTHER HARDWARE DESCRIPTION QUANTITY½” PVC Pipe 6m length section 31-1/2” or 2” pipe Small section 3”-

4” long

1

PVC glue Big tin 2Teflon tape Thicker type 4Nylon twine Thin but strong 1 skeinScreen Window or poultry

netting

5m

Shade cloth Plastic 4m

53

Wire Med. Gauge, Al or

steel

1kg (>10m)

Flexible tubing5/8” diameter 4-5kg or (50-60)m

Sand paper Med.grit 1 sheetBolt, nut and

two washers

To fit float

valve

Armature

Silicon sealer 1 tube

The above plumbing parts summary includes PVC

fittings for connecting the water system to existing

water supply and point-of-use infrastructure, as well

as a number of recommended spares. PVC connections

are installed in the HDPE drums using a knife to

carefully cut holes the diameter of ½” male PVC

threaded couplers. Connections should be snug enough

that the male couplers are screwed into drums,

helping to minimize leaks. Silicone is applied to

male-female couples spanning tank walls also to help

prevent leaks. Liberal use of Teflon tape on all

threaded connections is highly recommended.

54

b) SOURCE (BOREHOLE): water is generated from the ground

by means of borehole. Factors affecting the location

of a borehole include proximity to waste dump sites,

cemeteries, septic tank, oil pipelines and a large

sewage centre; distance of borehole from storage tank

must not be more than 50m. The depth of borehole as

directed by the National Agency for Food Drug

Administration and Control (NAFDAC) must be at a

minimum of 100-150ft depending on the topography.

c) Sand Bed

This is also known as sand bed filter. It contains

three different types of sand arranged in other of

size in three layers. This sand bed is arranged in

layers to ensure effective purification. Starting

from the bottom of the cylinder, the first layer

contain pebble stones, this can also be alternated

with gravel because of their similar sizes. The

second layer is coarse sand, this is smaller in size

than the pebble stone and finally, the last layer

which is the uppermost layer of the sand bed filter

is the fine sand which is more smooth and smaller in

size than the pebble and coarse layer. Water enters

the sand bed filter from the bottom of the cylinder

and leave from the top. The sand bed filter helps to

55

remove particulate solids in the raw water using the

principles of filtration and fluidisation.

Fig 3.1 flow direction of water into sand bed filter

Fig 3.2 various samples of stones and sand contained

in the sand filter

56

Figure 3.2 shows the various stones and sand

contained in the sand bed filter, a) is pea gravel

which is at the base of the sand bed filter column

where it is filled to 30cm in height, next is the

pebble stone filled to the 15cm mark from the pea

gravel region. C is the coarse sand with 15cm height

from the pebble stone and lastly is the sharp or fine

sand filled to the 25cm from coarse stone. Note , not

in all cases this four sand are combined. ((e) and

(f)) can be used to sieve mixed river gravel to

obtain pea gravel fraction.

Window screen (f) or poultry netting can be used to

sieve sand to obtain coarse and fine fractions.

This removes turbidity (particles) and some dissolved

matter that sticks to the surfaces of particles as

they settle. One or more times during the year

(depending upon source water quality), the large

valve at the bottom of the gravel filter is opened,

rapidly reversing the direction of flow through the

filter (“backwashing”) in order to flush out the

accumulated sediment and organic matter.

57

Fig 3.3 designed sand

bed filter

d) CARBON FILTER (G.A.C): This filter contains two

layers which the pebble (or gravel) stone layer and

the granular activated carbon layer. The granular

activated carbon is a form of carbon with a small low

volume pore which increases its surface area for

adsorption and chemical reaction. One grain of GAC

has a surface area of 500m3. GAC helps to remove

chlorine in cases where chlorination is done,

improves the taste and odour of the water, colour

pigment, lead, arsenate and trihalomethane.

58

Fig 3.4

sample of activated carbon in its lump and granulated

form

The carbon filter functions primarily by the process

of adsorption.

Adsorption, which signifies a surface interaction

between dissolved species and the char, is distinct

from absorption, which essentially means “to soak up”

or “to take into.” To be exact, however, in water

treatment contaminants diffuse into char pores

(absorption) where they bind to char surfaces

(adsorption).

This has led wide use of the nonspecific term

“sorption.” The porosity and large surface area of

chars provides a multitude of reactive sites for the

attachment of dissolved compounds. These reactive

sites can bind non-problematic dissolved organic

compounds as well as targeted hazardous contaminants.

Background dissolved organic matter, present in all

natural waters, can occupy sites on char surfaces and

thereby exclude contaminants of concern. This is

59

called “fouling.” Fouling in char filters is

mitigated by upstream unit processes – in our case,

the gravel and sand filters – that act to remove a

substantial portion of background dissolved organic

matter from the source water before it encounters the

char. The principle is to achieve a high level of

treatment prior to the char filter, in order to “save

the carbon” for removal of targeted problematic

dissolved compounds that make it through the previous

treatment steps.

The char filter is placed after the gravel and sand

filters in order to target specific components of

background organic matter (for example, compounds

that cause undesirable tastes, odors, or appearance)

or synthetic organic compounds (SOCs) such as

pesticides, pharmaceuticals, fuel compounds, etc.,

that are not well removed by the preceding unit

processes.

e) REVERSE OSMOSIS SYSTEM: This system contains three

membrane sections which are spiral wound to separate

dissolved solid. Reverse osmosis is a membrane

separation process in which feed water flows along

the spiral membrane surface under pressure. Purified

water permeates the membrane and is collected while

60

the concentrated water containing dissolved and

undissolved material that does not flow through the

membrane is discharged of the drain. The key

requirement of RO process are a membrane and water

under pressure, other requirement includes pre-

filtration to remove suspended impurities and carbon

to remove chlorine (damages the membrane) except

cellulose tri acetate(CTA) membrane which is chlorine

tolerant membrane. This removes 90-99% of dissolved

impurities depending on the impurity and composition

of water. RO system removes salt, microorganism and

many high molecular weight organics. The system

capacity depends on the water temperature, total

dissolved solid (TDS) in feed water, operating

pressure and the overall recovery of the system.

* CHARACTERISTICS OF THE RO SYSTEM

Capacity: 6000L/H

Voltage: 220V/50Hz

Rated power: 11KW/H

Water recovery rate: 50-75%

Salt rejection rate: 96-98%

Land area: 10000 x 2500 x 3500mm

61

ADVANTAGES OF RO SYSTEM

1) Can produce pure water continuously and highly

automatic

2)No need chemical to regenerate, easy operation.

3) Automatic switch on when low water level and

switch off when high water level

4)Production water conductivity meter can test the

monitoring quality on line continuously

5)Low operation cost and long life span

6)Low power consumption

7)Auto flush/backwash

8)Auto membrane flush

Fig 3.5 R.O system

62

Fig

3.6 flow through membrane

Fig 3.6

membrane

f) CONDUCTIVITY METER: This is a device attached to

the RO system. It has a monitoring unit and button

which control pumps of the RO system and also measure

the level of purity of the water. It controls raw

water pump, mixing pump (mixes water and ozone), HPP,

flush pump. It receive signal from a device attached

to the security filter and HPP. The monitoring unit

displays the purity of level in unit of micro

Siemens/centimeter (µ/cm).

63

For Pure

water………………………… 20-50(µS/cm)

Ultra pure water…………………………….0-

18(µS/cm)

g) OZONE GENERATOR: This is a small stainless steel

box which generates ozone (O3) from oxygen and it is

mixed with water from RO system by the mixing pump

before it is discharged to the pure water tank. Ozone

is an allotropic form of oxygen, O3. Because it is an

unstable gas, it must be generated at the point of

use. Ozone is a very effective, clean oxidizing agent

possessing powerful antibacterial and antiviral

properties. Short half-life may allow treated water

to be discharged without harm to the environment.

However, the shorter half-life reduces contact in a

treated water system, so the far reaches of a water

system may not receive adequate treatment.

64

Fig 3.8 onsite ozone generator

Fig 3.9

reaction formation of ozone in generator

This is an onsite generation process for ozone where

dry air or oxygen is passed through system of high

voltage electrode. Ozone is one of the strongest

oxidant and disinfectant available. It is often

applied for oxidation rather disinfection.

ADVANTAGES OF OZONE

1)Strongest oxidant/disinfectant available.

2)Produce no chlorinated THMs, halo acetic acid

(HAA).

3)Effective against cryptosporidium at high

concentration.

65

4)Used with advance oxidation processes to oxidize

organic compound.

LIMITATION

1) Process operation and maintenance require high

level of technical competence

2) Forms brominates by-product.

3) Break down more complex organic matter; smaller

compounds can form microbial re-growth in

distribution system

4) High operation and capital cost than chlorination

5) Difficult to control

h) PURE WATER TANK: This stores the treated water

and from here it is transported to various sections

(sachet and bottle section) for sealing and

capping.

i) MICRO FILTER: The micro-filters also known as

depth filters include one 0.5µ carbon micro filter

and two sediment filters of 1.5µ and 5µ

respectively arranged in series. The depth filters

have an efficiency of about 99%. The carbon micro

filters is packed with a carbon cartridge which

further improves the taste and the odour of the

water as well as reduces the chlorine content while

66

the sediment micro filters traps sediment that may

be present in the water and must have escaped RO

system and sand filter. The sediment micro filters

are designed in such a way that the bigger

sediments are trapped at the top while smaller ones

are trapped at the bottom.

Fig 3.10 three micro

filter of different microns

Fig 3.11 cartridge in micro filter

j) ULTRA VOILET STERILIZER: This is the last

equipment used in the treatment process before the

actual production of the bottle or sachet water. It

consist of a stainless steel chamber which contains

a mercury vapour lamp, the lamp is in a quartz

sleeve which protect it from direct contact with

water. Water enters the chamber at the upper part

and then exposed to intense light from mercury lamp67

then exit at the lower end. The UV sterilizer is

effective for microbial treatment by destroying the

chromosomes. UV sterilisers are inexpensive to buy

and maintain. Add no chemical to the water and

leave no by-products. Water flow rate and turbidity

and strength of lamp affect the UV steriliser.

Fig 3.12 Ultra violet steriliser

Fig 3.13 flow direction in UV steriliser

Fig 3.14 EMW section of UV steriliser

68

Fig 3.15 effect of UV steriliser

on microbes DNA

k) PUMPS: The pumps used for the process are electric

water pump with pumping capacity of 1 horse power

(1HP), maximum flow rate of 58l/min and maximum

height of 48m. Pump B is used for pumping raw water

from raw water tank to the filters C and D. Pump F

is a high pressure pump with specification of 141m,

flow rate 12m^3/hr, power 11KW and 2900r/min. It

pumps the water filtered by sand and carbon filter

bed through the Reverse Osmosis (RO) membrane. Pump

L is used to pump treated water from tank K to

consumption section.

69

Fig 3.16 treatment plant design

1)Raw water tank

2)Sand bed filter

3)Carbon filter

70

4)Security filter

5)High pressure pump(HPP)

6,7,8) Reverse Osmosis Membrane

9) Ozone generator

10) Pure water tank

11,12,13) Micro filters(5µ,1µ,0.5µ)

14) Ultra violet sterilizer

3.2 CHLORINATION: This is the process of

adding chlorine to water as a method of water

purification to make it fit for human consumption

as drinking water. Chlorine has various functions

in water treatment, these includes disinfection,

control of microorganism, removal of ammonia,

control of taste and odour, colour reduction,

destruction of organic matter. Chlorine is not

added to water in its free state but rather in

combination with calcium or sodium as

hypochlorite (i.e. Ca(OCl)2 and NaOCl). Ca(OCl)2

is more stable and contains large amount of

chlorine so it is used in place of NaOCl.

Chlorination is carried out in raw water tank.

The solution is prepared by first putting a

71

quantity of Ca(OCl)2 (5ppm) in a flat bottom

flask and water is added. This solution is

emptied into the raw water tank and then water is

pumped into the tank and allowed to mix for

45mins after which it is flushed out until

chlorine odour is not perceived. The calcium

hardens and clogs up particles in water.

Performing chlorination requires a face mask and

a lab coat.

3.3 FILTRATION

Filtration occurs in the sand filter, carbon

filter, water filter cartridges and reverse

osmosis. Details of function and properties of

the equipment are discussed in previous chapter.

The water filter cartridge is a sediment removal.

It is a polypropylene string wound cartridge

which helps to remove dust, rust, scale and other

sediments. It can process water at temperature

not exceeding 70 degree Celsius.

72

Fig 3.17 filtration in sand and carbon bed

73

3.4 FLOW DIRECTION

Raw water is pumped from the source ( raw water tank)

with a surface pump. The water is pumped through the

san and carbon bed filter where particulate

solids ,chlorine, odour e.t.c as explained earlier is

removed. From the carbon bed it is pumped through the

reverse osmosis via a high pressure pump. Ozone from

an onsite ozone generator is introduced into the

water to disinfect the water of bacterial before it

is stored in a pure water tank. It is further sent

through the three micro filters to remove impurities

which might result from death of microbes and finally

it is sent through a UV sterilizer which kills

bacterial by cell destruction and makes the water

safe for drinking.

3.5 CONCLUSION

Treatment of surface water for domestic and

industrial usage requires the application of the

appropriate treatment method and availability of

improved equipment to be used.

This requires that there should be

proper understanding of the composition

of the raw surface water with a view to 74

knowing the contaminant and their

sources. This helped in knowing the

pattern and type of design treatment

plant required in achieving portable

water for consumption.

Control of pollutant and contaminant in

surface water meant for public or home

water supply system is of great concern

to all and should be giving proper

adherence.

The designed treated plant has the

ability of producing 6000L/H and it

contains some electrical apparatus and

glass material so care should be taking

to prevent shock and breakage.

It is good to know that other methods which

are cheaper and more economical exist but

cannot be used for industrial scale

production due to low production. It is

therefore recommended to be used if for

home purposes.

75

REFERNCES

76

Coulson and Richardson, second Edition (1968) p145,

Particulate Technology and separation process.

How it works series, pure wateroccassional.net,

retrieved 08/12/2013

(PDF) Applied membrane incorporation

(PDF) Safe drinking water foundation

U.S Environmental Protection Agency June (1989),

procedures for water treatment.

WHO (ED) (1984), Guideline for drinking water

quality, vol 1, Recommendation, WHO Geneva.

77