This document discusses sources and effects of water pollution on human health. It outlines various sources of water pollution including sewage, industrial waste, pesticides, fertilizers and others. It describes the waste water treatment process including preliminary, primary, secondary and tertiary treatments. The secondary treatment involves biological processes like activated sludge process, trickling filters and anaerobic digestion to remove organic matter. Tertiary treatment further removes nutrients and disinfects the water. The document provides information on water quality standards and processing steps to treat domestic and industrial waste water.
SOURCES AND EFFECTS OF WATER POLLUTANTS ON HUMAN HEALTH, QUALITY STANDARDS FOR DRINKING WATER AND WASTE WATER TREATMENT
1. SOURCES AND EFFECTS OF WATER
POLLUTANTS ON HUMAN HEALTH, QUALITY
STANDARDS FOR DRINKING WATER AND
WASTE WATER TREATMENT
Presented By:-
JYOTI DEVENDRA ADALA
MSC PART 1
2. WATER POLLUTION
Water pollution is
defined as any
adverse change in
composition and
condition of the
water which tend to
lower its quality and
cause health hazard
or makes it unfit for
domestic use.
3. SOURCES AND EFFECTS OF WATER
POLLUTION
1) Sewage and domestic
waste
2) Industrial wastes and
effluents
3) Insecticides and
pesticides
4) Detergents and
fertilizers
5) Siltation
6) Thermal pollution
7) Radioactive materials
4. SEWAGE AND DOMESTIC WASTES
Nearly 75% of water pollution is due to sewage and domestic wastes.
Biological oxygen demand (BOD)- The amount of oxygen consumed by
microbiological action when 1000ml sample of water containing known amount of
oxygen is incubated for 5 days.
Water having DO content below 8.0 mg/l is considered as polluted. Heavily polluted
water have DO content below 4.0 mg/l.
Chemical oxygen demand (COD) - It is the oxygen required by organic substance in
order to oxidise them by a strong chemical oxidant.
5. INDUSTRIAL WASTES AND
EFFLUENTS
The industrial wastes and their effluents include poisonous
materials like acids, alkalis, salts, phenols, cyanides, zinc,
insecticides which makes water toxic and deoxygenated and
eventually do not support aquatic life.
MERCURY- Minamata disease.
OILS- Oil reduce rate of oxygen uptake by water, retards light
intensity by 90%.
BLACK FOOT DISEASE (Arsenic), ASBESTOSIS (Asbestos),
BERYLLIOSIS (Beryllium), ITAI- ITAIdisease (Cadmium).
6. INSECTICIDES AND PESTICIDES
They are biologically active
chemicals are used for pest
control. These include DDT
(dichlorodiphenyltrichloroeth-
ane), aldrin etc.
Increased accumulation of
these toxic substance in the
food chain at high trophic
level is called BIOLOGICAL
MAGNIFICATION.
7. DETERGENTS AND FERTILIZERS
Detergents are used as cleaning agent and derived from surfactant (10% -
30%, alkyl benzene sulphonate), builder (10% to 15%, sodium phosphate )
and other ingredients.
Fertilizers such as nitrates and phosphates are used to improve crop yield
reach through irrigation, rainfall and drainage into rivers and ponds. They
cause serious illness metheamoglobin.
EUTROPHICATION
8. OTHER SOURCES
SILTATION :- Seen in hilly streams and creates turbidities.
THERMAL POLLUTION:- Heated waste water from power plants
and industries which raises the temperature of water to a harmful
level.
RADIOACTIVE MATERIALS :- Radioactive pollutants get their way
into water streams from various sources such as nuclear reactors,
nuclear power plants and nuclear test.
10. PRELIMINARY TREATMENT
This involves the removal of floating material,
settle able inorganic solids, and greasy materials.
SCREENERS - Device with opening and further
classified as coarse (75-150mm), medium (20-
70mm) and fine (<20mm).
SHREDDER - Special device that cut and retain
floating and suspended material.
GRIT CHAMBERS -Heavy inorganic material can
be removed. Based on principle of
sedimentation.
SKIMMING TANK -Greasy material can be
removed using skimming tank which is divided
into 3 compartments.
11. PRIMARY TREATMENT
It is aimed at removal of suspended organic solids that cannot be removed in preliminary
treatment. It involves the process of sedimentation.
Sedimentation is the separation from water by gravitational settling if suspended particles
are heavier than water
Sedimentation tank have inlet zone, settling zone, outlet zone, sludge zone.
Chemicals are added to aid sedimentation . Examples are alum, iron salts, lime etc.
12. SECONDARY/ BIOLOGICAL TREATMENT
It is required to remove dissolved and fine colloidal organic matter. This
process involves the use of microorganisms that decompose the unstable
organic matter to stable inorganic forms.
13. AEROBIC SUSPENDED GROWTH
TREATMENT PROCESS
1) ACTIVATED SLUDGE PROCESS:- The sewage containing organic matter with
microorganism is aerated in an aeration tank.
Advantage- cost effective, sludge has higher fertilizer value.
organic matter + O2 CO2 + NH3 + H2O + new cells
2) AERATED LAGOONS :- They are also known as aerated ponds, are the
facultative stabilization ponds wherein surface aerators are installed to
overcome bad odors.
14. AEROBIC ATTACHED GROWTH
TREATMENT PROCESS
1) TRICKLING FILTERS :-
It has a bed of
coarse, hard, porous
material over which
sewage is percolated
or trickled and
microorganisms
attached to medium
degrade the organic
matter.
2) PACKED BED
REACTORS:- A reactor
is packed with a
medium to which
microorganism get
attached and form
biofilms.
15. ANAEROBIC SUSPENDED GROWTH TREATMENT
PROCESS
ANAEROBIC DIGESTION :- Process is carried our
in a air tight reactor.
It involves 3 stages namely hydrolysis,
acidogenesis (clostridium sp. , cornybacterium ),
methanogeneis (methanococci,
methanobacillus).
ANAEROBIC ATTACHED GROWTH TREATMENT
PROCESS
ANAEROBIC FILTER PROCESS:- Consist of
column fitted with solid media for treatment
of organic matter in sewage.
Due to solid media bacterium is retained in the
column.
16. POND PROCESS
Pond process treatment is carried out in a specially designed and constructed ponds called
stabilization ponds which are large and shallow.
a) Aerobic :- They contain bacteria and algae in suspension and they show symbiotic
relationship.
b) Anaerobic :- Useful for treatment of high strength organic matter and solid containing
sewage water.
c) Facultative ponds :- Combination of both aerobic and anaerobic process.
18. TERTIARY TREATMENT
Only 1-2 % domestic sewage receives tertiary treatment which is the most
advance phase of sewage treatment. The tertiary treatment is needed under the
following circumstances
When the quality if effluent to be discharged does not meet the standard
requirement.
When there is necessity to remove dissolved solids by ION EXCHANGERS.
To remove nitrogen and phosphorus.
To remove pathogenic organisms through DISINFECTION.
19. ION EXCHANGE METHOD:- Involves displacement of one ion by another. The
exchange occurs between the ions of insoluble exchange material and ions of
the different species in water sample. Two types are cation and anion
exchangers.
CARBON ADSROPTION :- The main purpose of this process is to remove
dissolved organism compound from the effluent.
20. REMOVAL OF NITROGEN: Through nitrification and denitrification.
REMOVAL OF POHSOPHORUS:- Waste water is mixed with lime. This lime reacts
with phosphorus containing compounds in the effluent to form insoluble calcium
phosphate which settles at the bottom.
21. Broadly refers to the selective destruction or inactivation of disease causing
organisms. The very purpose of disinfection is to control the various water
borne diseases.
Characteristic of ideal disinfectant
Toxic to pathogen at low concentration.
Soluble and stable in water.
Non toxic to man and higher organisms.
Cheap and easily available.
Agents :- chemical and radiation.
DISINFECTION
