3. UNIT I INTRODUCTION
Undesirable waste water
characteristics – Characteristics of
industrial waste waters – Waste
water characteristics – Estimating
the organic content – Measuring the
efficiency toxicity – In plant waste
control and waste reuse – Storm
water control.
4. INTRODUCTION
Industrial waste is the waste produced by industrial
activity which includes any materials that is rendered
useless during a manufacturing process.
The waste materials generated by industries or
industrial processes, is called industrial waste. It
includes chemicals, trash, oils, solvents, dirt and
gravel, many harmful gases etc. These are dumped in
seas, rivers or land without adequate treatment.
Thus, become a large source of environmental
pollution.
5. Types or Classification of Industries
• Industries can be classified into the
following four groups,
• (i) Primary Industry
• (ii) Secondary Industry
• (iii) Tertiary Industry
• (iv) Quaternary Industry
6. PRIMARY INDUSTRY
They are further classified into the following
types, such as
• Genetic Industry
• Extractive Industry
• Manufacturing Industry
• Construction Industry
• Service Industry
7. Causes of Industrial waste
• a. Lack of policies to control waste
• b. Unplanned industrial waste
• c. Presence of large number of small
scale industries
• d. Inefficient waste disposal
• e. Leaching or resources from out
natural world.
8. Types of industrial wastes
• Industrial waste can be divided into
following two types –
• Biodegradable industrial waste
• Non – biodegradable industrial waste
9. Biodegradable wastes
• Those waste materials which can be
decomposed into simpler unharmful
substances by the action of microorganisms
are called biodegradable wastes.
• Some industries such as the paper industry,
food industry, sugar industry, wool industry
etc. mostly produce biodegradable industrial
wastes.
• Management of these wastes can be done at
low cost and easily.
10. Non-biodegradable wastes
• Non-biodegradable waste cannot be further
decomposed via the action of the microorganisms.
• Such waste is the major source of toxins in the
landfills. Chemicals, metals, plastics, paints, rubber
etc. are examples of non-biodegradable wastes.
• These materials can remain as landfills for thousands of
years without any damage.
• Toxins from metals and plastics get soaked into the
earth and pollute the soil and water sources.
• Cleaning materials such detergent, phenols etc.
producing industries, coal industries, dying
industries etc.
• produce a large amount of non-biodegradable
industrial waste. These types of wastes are difficult to
manage and very toxic in nature.
11. Effects of Industrial Waste
• Liquid industrial waste which is thrown
into the sea is at an alarmingly dangerous
level for marine ecosystems.
• Industries release many harmful gases
such as carbon dioxide, sulfur dioxide,
nitrogen oxides etc. which cause air
pollution.
12. • In industrial wastewater nitrates and
phosphates are there which often cause
eutrophication.
• Generally, air around industries is highly
polluted and causes skin, eyes, throat, nose
and lungs diseases
13. • It is one of the main causes of global
warming.
• Industrial wastewater destroys useful
bacteria and other microorganisms present
in soil.
• Some industries cause sound pollution as
well.
• Industrial wastes and industries are
destroying natural habitat of many species
and responsible for wildlife extinction.
14. INDUSTRIAL WASTEWATER
• Industrial wastewater is not just a by-
product of oil and gas or mining and
chemical manufacturing companies,
but also a by-product of food and
beverage processing industries,
essential in the making of the clothes
on your back, the shoes on your feet,
the computer at your fingertips, and
the car your drive.
15. •Organic matter, metals,
and the like found in the
wastewater must be
removed before the
water can be safely
discharged back to land,
16.
17. Categories of pollutants
Industrial water contains a large variety of
pollutants which as categorized as follows:
• Organic Pollutants
• Inorganic Pollutants
20. Industries Produce Industrial
Wastewater
a) Metal Finishers
b) Industrial laundries
c) Chemical Manufacturing
d) Mining
e) Steel/Iron Production
f) Oil and Gas Fracking
g) Power Plants
h) Waste water treatment plants
i) Food Processing
22. CHARACTERISTICS OF
INDUSTRIAL WASTE WATER
✓ A colloidal type of turbidity
✓ A typical Colour(Grey – yellowish)
✓ A low alkalinity(pH around 7.5)
✓ Large amount of Nitrogen,
entirely of organic origin
✓ They have an unpleasant odour
23. EFFECTS OF WASTEWATER
• Oxygen depletion on the body of water
• Presence of undesirable colour, odour and taste
in the water
• Reduced photosysnthesis
• Formation of blanket of suspended solids settling
at the bottom of the receiving body of the water
• The death of fish
• Toxicity added to the adequate life due to the
formation of mercaptans (mercaptan acts as an
odorant to make it easier to detect). ,
pentachlorophenol, sodium pentachlorophenate.
26. Colour
• Fresh domestic sewage is grey, somewhat
resembling a weak solution of soap.
• The colour of septic sewage is more or less
black or dark in colour.
• The colour of industrial wastewater depends
upon the chemical process used in the
industries.
• Industrial waste water, when mixed with
domestic sewage, may also add colour to it.
27. Odour
• Normal fresh sewage has a musty odour which is
normally not offensive, but as it starts to get
stale, it begins to give offensive odour.
• Within 3 or 4 hours, all the oxygen present in the
sewage gets exhausted and it starts emitting
offensive odour of hydrogen sulphide, gas and
other sulphur compounds produced by anaerobic
micro-organisms.
• Industrial wastewater may contain either process
of wastewater treatment.
28. Turbidity
• The turbidity of wastewater depends on the
quantity of solid matters present in the
suspension state.
• Turbidity is a measure of light-emitting
properties of wastewater, and turbidity test is
used to indicate the quality of waste
discharges with respect to colloidal matter.
• The turbidity depends upon the strength of
sewage or waste water. The stronger or more
concentrated the sewage, the higher is its
turbidity. Turbidity can be determined either
by turbidity rod or by Jackson’s turbidimeter.
29. Total Solids
• Sewage normally contains 99.9 per cent
of water and 0.1 per cent of solids.
Analytically, the total solids content (ST)
of a wastewater is defined as all the
matter that remains as residue upon
evaporation to 103 to 105°C.
• Total solids in wastewater exist in three
different forms (a) suspended solids (b)
colloidal solids and (c) dissolved solids.
30. CHEMICAL CHARACTERISTICS OF
WASTEWATER AND THEIR
DETERMINATION
(i) pH value
(ii) Chloride content
(iii) Nitrogen content
(iv) Fats, grease and oil content
(v) Sulphides, sulphates and H2S gas
(vi) Dissolved oxygen (DO)
(vii) Chemical oxygen demand (COD)
(viii) Bio-chemical oxygen demand (BOD)
(ix) Stability and relative stability.
31. pH VALUE
The test for pH value of wastewater is
carried out to determine whether it- is
acidic or alkaline in nature.
Fresh sewage is generally alkaline in
nature, (its pH value between 7.3 to 7.5).
A high concentration of either an acid (pH
≪ 7) or alkali (pH ≫ 7) in wastewater is
indicative of industrial wastes.
32. CHLORIDES CONTENT
• Chlorides are mineral salts and, therefore, are
not affected by biological action of sewage.
• Chlorides in natural water result from the
leaching of chloride-containing rocks and soils
with which the water comes in contact.
• Water softeners also add large quantities of
chlorides. Large amounts of chlorides may also
enter in wastewaters from industries like ice
cream plants, meat salting etc.
• Chlorides found in domestic sewage are derived
from kitchen wastes, human faeces and urinary
discharges etc.
• Human excreta, for example, contain about 6 g of
chlorides per person per day.
33. NITROGEN CONTENTS
• The presence of nitrogen in waste-
water indicates the presence of
organic matter in it.
• Nitrogen is essential to the growth of
Protista and plants and as such is
known as nutrient or bio-stimulant.
34. Nitrogen appears in the following five
different forms in waste-water
Ammonia nitrogen or free ammonia
Organic nitrogen
Albuminoid nitrogen
Nitrites nitrogen and
Nitrates nitrogen.
Fats, Grease and Oils
Surfactants
Phenols, Pesticides and Agricultural Chemicals
Toxic Compounds
Sulphates, Sulphides and H2S Gas
35. FATS, GREASE AND OILS
• Fats and oils are mainly contributed from kitchen
wastes, because they are major components of
food stuffs such as butter , vegetable oils and
fats.
• Fats are also commonly found in meats, seeds,
nuts and some fruits.
• Grease and oils are also discharged from
industries like garages, workshops, factories etc.
Fats and oils are compounds (esters) of alcohol or
glycerol (glycerine) with fatty acids.
• Such matters float on the top of sedimentation
tanks, often choke pipes in the winter, and clog
filters.
36. Surfactants (surface-active agents)
Surfactants come primarily from synthetic
detergents.
These are discharged from bathrooms, kitchens,
washing machines etc.
Surfactants (or surface-active agents) are large
organic molecules which cause foaming in
wastewater treatment.
Due to this, aeration of wastewater is hindered.
Alkyl-benzene-sulphonate (ABS), a type of surfactant
commonly used in synthetic detergents, is more
troublesome since it is not biodegradable.
37. Phenols, Pesticides and Agricultural
Chemicals
• Phenols are mostly found in industrial
wastewater.
• If such wastewaters are directly discharged
into receiving streams, they cause serious
taste problems in drinking water, specially
when water is disinfected by chlorination.
• However, phenols can be biologically
oxidized if the concentrations are upto 500
mg/l.
38. Toxic Compounds
• Copper, lead, silver, chromium, arsenic and
boron are some of the cations which are toxic to
micro-organisms resulting in the malfunctioning
of the biological treatment plants.
• These results from industrial wastewaters. Some
toxic anions, including cyanides and
chromates, present in some industrial wastes
also hinder the wastewater treatment facilities.
• Hence their presence should be taken into
consideration in the design of biological treatment
plants.
39. Sulphates, Sulphides and H2S Gas
• Sulphates and sulphides are formed due to
decomposition of various sulphur containing
substances present in wastewater.
• The sulphate ions (SO4) occur naturally in
most water supplies and hence they are also
present in wastewater
• Sulphur, required in the synthesis of proteins is
released in the degradation.
40. Following are the gases that are
commonly found in untreated
wastewater
(i) Nitrogen (N2)
(ii) Oxygen (O2)
(iii) Carbon-dioxide (CO2)
(iv) Hydrogen sulphide (H2S)
(v) Ammonia (NH3)
(vi) Methane (CH4).
41. Oxygen in a sample of wastewater is
reported in the following three ways
(a) Oxygen consumed
(b) Dissolved oxygen and
(c) Oxygen demand.
42. The demand of oxygen may be
expressed in the following ways
(i) Biochemical oxygen demand (BOD)
(ii) Chemical oxygen demand (COD)
(iii) Total oxygen demand (TOD)
(iv) Theoretical oxygen demand (Th. OD).
In addition to these, the amount of organic
matter present may also be determined by
the total organic carbon (TOC) test.
43. Biochemical Oxygen Demand (BOD)
• The BOD may be defined as the oxygen
required for the micro-organisms to carry
out biological decomposition of dissolved
solids or organic matter in the
wastewater under aerobic conditions at
standard temperature.
• It is the most widely used parameter of
organic pollution applied to both
wastewater as well as surface water
44. Chemical Oxygen Demand (COD)
• The BOD test takes a minimum of 5 days’
time, and due to this, it is not useful in
the control of treatment processes.
• An alternative test is the COD test, which
can be used to measure content of
organic matter of both wastewater as
well as natural waters.
• COD can be determined only in 3 hours
in contrast to 5 days of BOD test.
45. Total Oxygen Demand (TOD)
• The TOD method is based on the
quantitative measurement of the
amount of oxygen used to bum the
organic substances and to a minor extent,
inorganic substances.
• It is thus a direct measure of the oxygen
demand of the sample.
• The test is conducted in a platinum-catalysed
combustion chamber.
46. Theoretical Oxygen Demand (ThOD)
• This is a theoretical method of computing the
oxygen demand of various constituents of the
organic matter present in wastewater.
• The organic matter present in the wastewater
may be of animal or vegetable origin,
consisting of principal groups such as
carbohydrates, protein, fats and products of
their decomposition.
• Each one of these is a typical combination of
carbon, hydrogen, oxygen and nitrogen, based
on its chemical formula.
47. BIOLOGICAL CHARACTERISTICS OF
WASTEWATER
Domestic sewage, by its nature, contains
enormous quantities of micro-organisms.
The biological characteristics of sewage are
related to the presence of these microorganisms.
The sanitary engineer must have considerable
knowledge of
(i) principal groups of microorganisms found in
water and wastewater
(ii) pathogenic organisms in wastewater, and
(iii) organisms used as indicators of pollution.
48. The various micro-organisms found in water or
wastewater may be broadly classified under
three categories
(i) Aquatic plants
(ii) Aquatic animals
(iii) Aquatic moulds, bacteria and
viruses.
49. (i) Aquatic Plants:
Under this category, the following are included
(a) Spermophyta – Water weeds.
(b) Bryophyta – Mosses and lever words.
(c) Pteridophyta – Ferns and horsetails.
(d) Thallophyta – Algae.
50. (ii) Aquatic Animals
They include the following
(a) Vertebrate – Fish and amphibians.
(b) Mollusca – Mussels, snails, slugs,
limplets, cocklets
(c) Arthopoda – Crustacea, insects, spiders,
mites.
(d) Worms – Aquatic earthworms, thread
worms, rotifera.
(e) Metazoa –Hydra, polyzoa.
(f) Protozoa – Endameba histolytica etc.
51. (iii) Aquatic Moulds, Bacteria and
Viruses
• Strictly speaking, moulds (or fungi),
bacteria and viruses come under the
category of aquatic plant, but because of
their special importance, they are
generally kept in a separate category.
52. AEROBIC PROCESSES
The work of the aerobic bacteria, i.e.
combination with oxygen is called oxidation.
Aerobic bacteria utilise free oxygen as an
electron acceptor.
The end products of aerobic activity are CO2,
H2O, SO4, NO3, NH3 and more bacteria.
The bulk of the available energy finds its way
into cell mass or heat, yielding a stable
effluent which will not undergo further
decomposition
53. ANAEROBIC PROCESSES
The work done by anaerobic bacteria, viz.
decomposition of organic matter is called
putrefaction and the result is called
liquefaction, as the solid organic matter is
dissolved by enzymes.
Anaerobic bacteria oxidise organic matter
utilising electron acceptors other than
oxygen.
In carrying out their metabolic processes, they
produce CO2, H2O, H2S, CH4, NH3, N2,
reduced organics and more bacteria
54. The end products of an anaerobic
fermentation are likely to be odourous.
The production of a stable effluent is
unlikely since wastes do not usually contain
sufficient electron acceptors to permit
complete oxidation.
In the first stage, the anaerobic bacteria
decompose complex organic matter into
simple organic compounds while in the
second stage, the aerobic bacteria oxidise
them to form stable compounds
55. ESTIMATING THE ORGANIC
CONTENT
• The organic matter present in the water
body can be analyzed in laboratory by
determining Biochemical Oxygen
Demand (BOD), Chemical Oxygen
Demand (COD), and by determination of
Total Organic Carbon (TOC).
58. Biochemical Oxygen Demand (BOD)
• The BOD can be defined as the oxygen
required for biochemical oxidation of organic
matter present in the water under aerobic
conditions
59.
60.
61. BOD Test
• Biochemical oxidation is slow process and
theoretically takes an infinite time to go to
completion i.e. complete oxidation of
organic matter. During the first few days the
rate of oxygen depletion is rapid because of
the high concentration of organic matter
present.
• As the concentration of organic matter
decreases, so does the rate of oxygen
consumption.
62.
63. Chemical Oxygen Demand (COD)
• During COD determination total organic
content of the waste is oxidized by dichromate
in acid solution.
• In this test to determine the oxygen
requirement of the wastewater, strong oxidizing
agent ‘potassium dichromate’ is used.
• Acidic environment is provided to accelerate
the reactions by addition of sulphuric acid.
64. COD test measures virtually all oxidizable organic
compounds whether biodegradable or not,
except some aromatic compounds which resists
dichromate oxidation.
The COD is proportional to BOD only for readily
soluble organic matter in dissolved form e.g.
sugars.
No correlation between BOD and COD exists
when:
Organic matter is present in suspended form;
under such situation filtered samples should be
used.
Complex wastewater containing refractory
substances.
67. Acute toxicity
Acute toxicity is the kind of harm which
describes classical poisoning effects.
People often compare measures of acute
toxicity expressed as LD50, which measures
lethal effects from a large one-time dose,
when trying to place these exposures in
context. As the famous quote goes, “the dose
makes the poison” characteristics as shown in
fig
68.
69. CHRONIC TOXICITY
• Outside of cases of acute poisoning, most of
the time we are interested in finding the
lowest level of daily exposure that causes
harm.
• As mentioned above, LD50 values give us very
little information about these long-term
effects. Instead, chronic toxicity metrics are
based on the “Lowest Observable Adverse
Effects Level” (LOAEL) and the “No
Observable Adverse Effects Level” (NOAEL)
characteristics as shown in fig
70.
71. IN PLANT WASTE CONTROL
AND WASTE REUSE
Waste Management
• Waste management is a process that
combines all the activities necessary for
managing waste – collection of garbage,
transportation, and disposal of the trash.
• Its primary purpose is to lessen the waste of
unusable materials and avoid potential
environmental and health risks.
72. • The waste can be in any form – liquid,
solid, gas – but with the help of waste
management processes, each state has its
own disposal methods.
• It offers a variety of solutions to recycle
the waste, which ultimately leads down to
finding ways to recycle it as a valuable
resource.
73. One of the ways to put that plan into action is through
the 3 Rs of waste management — Reduce, Reuse,
Recycle.
1. Reduce means to cut back on the amount of
trash we generate.
2. Reuse means to find new ways to use things
that otherwise would have been thrown out.
3. Recycle means to turn something old and
useless (like plastic milk jugs) into something
new and useful (like picnic benches, playground
equipment and recycling bins).
74. WASTE REDUCTION
Waste reduction or source reduction is the
practice of preventing waste by decreasing or
eliminating the amount of materials initially used.
Some examples of waste reduction include
purchasing products in bulk quantities rather than
single servings, like cereal or potato chips.
Another example is to use reusable serving
utensils and trays instead of disposable items; or
to manage grass clippings by using a mulching
lawn mover and leaving clippings on the lawn.
75.
76. Effective solid waste disposal
and management methods
1. Preventing or Reducing Waste
Generation
2. Recycling
3. Incineration
4. Composting
5. Sanitary Landfill
6. Disposal in Ocean/Sea
7. Plasma Gasification
77. Benefits of Waste Management
1. Better Environment
2. Reduced Pollution
3. Energy Conservation
4. Increases Employment Opportunities
5. Helps Create a Change
79. STORM WATER CONTROL
Storm water management means to
manage surface runoff.
It can be applied in rural areas (e.g. to
harvest precipitation water), but is
essential in urban areas where run-off
cannot infiltrate because the surfaces are
impermeable
80. Stormwater management is essential to
prevent erosion of agricultural land and
flooding of inhabited urban or rural
areas.
Both cases can cause severe damages and
contamination of the environment if
sanitation facilities are flooded.
This results in high costs and notably
massive suffering for the local
communities
