This includes how effluent water treatment is taking place in an industry

1. Effluent Water Treatment Plant (ETP)
• Introduction
Protecting ecology is our duty. We are thus protecting our future generation. Waste
water treatment has assumed great significance in today’s context where protecting the
environment is a prime concern. The main objective of waste water treatment is to treat the
effluent before it is discharged so that the environment is not polluted. Waste water
treatment in general refers to treatment of suspended and floatable material, treatment of
biodegradable organics and the elimination of pathogenic organisms because untreated
wastewaters contain:
(a) organic and inorganic compounds,
(b) pathogenic or disease causing microorganisms,
(c) aquatic nutrients such as nitrogen and phosphorus and
(d) inert constituents such as sand and gravel.
The contaminants in waste water are removed by physical chemical and biological means.
These organisms are effectively removed by an enzyme called ENVIRO NZYME.
Wastewater treatment for the removal of Fat and Oil must be appropriate for the
physical form of Fat and Oil that is present. Fat and Oil in wastewater can exist in several
forms:
(a) very rarely as suspended particles,
(b) sometimes as attached to other particles,
(c) most likely as part of an emulsion.

2. • Purpose of Effluent water Treatment
The primary purpose of is to maintain sanitary conditions in the community and to remove
constituents that can pollute streams and rivers and cause these waters to be unswimmable
and unfishable. Polluted waters are harmful to fish and can interfere with the recreational value
of the waters. Because dissolved oxygen is a key element for the existence of fish or other
aquatic life, it is important to keep the dissolved oxygen concentration of streams and rivers at
a high enough level that the fish can live. A minimum of 4 to 5 mg/l of dissolved oxygen usually
is recommended to maintain good fish populations in streams and rivers. When organic wastes
enter a stream, the common bacteria in the stream use the wastes as food and use, the
dissolved oxygen in the water to digest the wastes. This can lower the dissolved oxygen
concentration of the stream to the point that the many types of fish cannot live. The
measurement of the oxygen used by the bacteria to consume the wastes is called the
biochemical oxygen demand (BOD) test. The greater the quantity of organic matter in the
wastes discharged to a stream, the more oxygen that will be used by the bacteria as they
consume the wastes. The removal of biodegradable organic matter is a major goal of
wastewater treatment. Therefore, the NMK agro industries has taken several measures to
reduce the worse impact of waste water on the environment.
• Factors to Consider implant an ETP
Any factory needing to install an ETP has to consider several factors. For example,
information about the wastewater from the factory is required, including quantity and quality.
To get this information the factory will have to take samples and have them analyzed at a
reputable laboratory. Some of the factors to be considered are presented in Fig
Figure 1: Considerations when Planning an Effluent Treatment Plant

3. • The process of Effluent Treatment Plant
Effluent water treatment plant is used to purify waste water and utilized water released by the
factory. As effluent water,
➢ Coconut water
➢ The water uses in the blanching tank
➢ The washing water in the production line
➢ Water uses to washing machineries
➢ The water and machineries use for washing floor of the factory
➢ Water utilizes by the people
are produced daily.
But only the water released by the blanching tank daily, washing water in the
production line and waste coconut water are sent to the ETP section. The other water produced
daily by the factory are filtered y the filter machines and others which are not harm to the
environment are released directly to the agricultural environment.

4. • The Running Procedure of ETP Plant,
• 01-Temparary storage tank (5000 l)
• 02-Pumping motor
• 03-Oxygen generating motor
• 04-Pumping motor
• 05, 06, 07, 08 –Filtering and settling tanks (1500 l)
• 11-Pumping tank
• 10-pH regulatory tank
• 09-Extra pumping water storage tank
• 12,13-Anaerobic bacterial decomposing tank
• 14,15- Aerobic bacterial decomposing tank
• 16- Water oxygenating tank (60000 l)
• 17- Secondary oxygenating / hollow fiber tank
• 18-Acquatic fauna growing tank
The water released by the factory first going to the temporary storage tank which is of
5000 l liters’ capacity. Then the water is sent to primary settling tank and then after 24 hours
the water is sent to secondary settling tank respectively the water is sent each settling tank.
Then the enzyme called Carbohydrase (Enviro enzyme) is added to the water tanks. The role of
that enzyme can be described as follows,
An enzyme is a chemical catalyst that breaks up long, complex waste molecules
(Hydrolytic reaction) into smaller pieces, which can then be digested directly by the bacteria.
Enzymes are manufactured and used by bacteria in order to digest waste. ENVIRO NZYME – G a
dry free flowing powder is a concentrated source of hydrolytic enzymes and eight strains of
natural bacteria that are genetically capable of producing concentrations of enzymes in waste
treatment systems under aerobic and anaerobic conditions. ENVIRO NZYME –G is used for
reducing the BOD, COD levels as well as reducing the sludge volumes odour and color in the
effluent and sewage treatment plants.

5. ENVIRO NZYME-G,when added helps to
• Remove odour
• Sludge volume will be reduced more, as more solids are digested.
• Sludge will be easier to pump, process and dewater, and will have less odour too.
• The capacity of the system will be effectively increased, because more waste can be
processed, more efficiently, in lesser time.
• The whole system will be able to absorb the shock of toxic influent.
• Easier to balance the treatment system.
• Bacterial Oxidation of the liquid phase will be faster and more complete
• Digesters will operate evenly and uniformly, easier planning and routine waste.
• Effluent water standards will be met more consistently, helping to maintain a clean
environment and safe drinking water for the population.
Dosage
Dosage rate will vary with retention times, BOD/COD ranges, water temperature, pH,
sludge built up and pond depth. Initial treatment of any waste system should be eight
times the volume of ENVIRO NZYME-G. Normal preventive maintenance* in oxidation,
lagoons, digesters, sludge pits, clarifiers, Imhoff tanks and collection system is 2ppm of
ENVIRO NZYME-G per day. The 2ppm is determined by the total weight of the waste water in
the system.
For one lakh liters of effluent, use 200 gms of enzyme per day.
• The normal preventive maintenance rates are based on the following criteria.
• Minimum retention time of 5 days.
• BOD ranges of 1150 to 250 ppm.
• pH of 6.5 to 7.5
Note:
If the product is to be used in a waste treatment system with almost continuous flow and
with hydraulic retention of less than 24 hrs, the dry products may be soaked in luke warm water
at 30C for 8 hrs in 1% water solution to fully activate the biological components of the products
and to allow the bacteria to get a quick start when introduced into the system. Soaking period of
over 10-12 hrs are recommended.
In multiple – level applications, it is recommended that ENVIRO NZYME-G be applied at
the lowest level first. Start at the bottom or end of the system from floor to floor or from section
as appropriate. The reason for this is that where ENVIRO NZYME-G to be applied at the top or
beginning of the system, the waste material washed away might cause problems in the lower
portion of the system unless this portion is already cleared. During normal preventive
maintenance, the point of application should be in an area which allows the product the max.
time in the system.
When describing the way of adding the enviro NZYME-G into the system, ENVIRO NZYME-G
should be activated by mixing them in a bucket of warm water (not hot water) for few minutes.
Pour the slurry into the system at a point where normal water flow will disperse it evenly. The
best way is to pour it into the waste stream inside the plant, or just before it flows out into the

6. waste stream inside the plant, or just before it flows out into the pond. If this is not possible, pour
it directly into the middle of the pond, or around the perimeter.
The results can be achieved after a period of time. Bad odours and sludge accumulations
take months and years to build up, and it will take some time to get rid of them. Begin the
treatment with double the normal weekly dosage for a period of 3 to 4 weeks. After this startup
period, one will begin to see significant improvements, and can cut back to normal weekly dose.
Severe accumulation of sludge may take one or more years to get eliminated.
A continuous treatment has to be maintained because of, the bacteria in these products
are very efficient at digesting waste-many time better than the natural bacteria. However, they
are not as “strong” as the natural bacteria. If the treatment is stopped, the natural occurring
batteries are undesirable because they work slowly, produce odours and can be pathogenic.
Solutions which disinfectant and do not chlorinate frequently can kill the bacteria. On
application increase the dosage of ENVIRO NZYME-G. ENVIRO NZYME-G contains a complex of
bacteria and enzymes which perform in an adqueous solution within the following optional
parameters:
pH
• optimum 7.0
• minimum 5.0
• maximum 9.0
• (Should not be too acidic)
Dissolved Oxygen
• optimum 2ppm
• minimum 1 ppm
Carbon/Nitrogen
• Ratio(C/N)
• Optimum 10:1
• Maximum20:1
Temperature
• optimum 30C
• minimum 10C
• maximum 40C
• Negative effects on the biological growth rates are possible in the presence4 of varying
concentrations of heavy metal in the adeeous solution (less than 20 ppm)
• Residence time or the time biology needs to acclimatize to break down the organic waste is 5
days.
Product Specification
Bacteria count
Aerobic bacteria Min 1.5 billion colonies/gm
Anaerobic bacteria Min 2.5 billion colonies/gm
Facultative bacteria Min 2.0 billion colonies/gm
Total plate count Min 6.0 billion colonies/gm
E. coli Absent in 0.1 gm
Salmonella Absent in 25 gm
Toxins Absent in 0.1 gm

7. Appearance
Medium tan, free flowing granular powder with a yeasty odour.
The process happening in the settling tanks during 24 hours’ period within one tank is
that effluent water is subjected to settle and sedimentation. This process is occurring in each of
four tanks. After 24 hours’ period a layer of emulsion can be seen on water. Subsequently this
type of emulsion layers can be seen on other tanks also. The emulsions and layers occur in the
tanks are collected to another tank. Basically Fats and oils are removed by skimming of water.
Then the substances collected to sedimentation tanks. After that oil mixed liquid on the
sedimentation is collected to plates and heated to extract oil. Then these oil extracted is used to
produce soap. The sedimentation is taken for the manufacturing of clay products and bricks.
This are used to seasoning of clay.
The water comes to the pumping tank is pumped towards the pH regulatory tank. When
describing why is controlling pH an important procedure in treating wastewater? Can be explained as
follows,
As a chemical component of the wastewater, pH has direct influence on wastewater
treatability — regardless of whether treatment is physical/chemical or biological. Because it is
such a critical component of the makeup of the wastewater, it is therefore critically important
to treatment.
The steps needed to control pH
First of all, the parameters have to be identified — the pollutants or impurities — that
are actually in the wastewater. Once the pollutants are identified, you should determine the
starting and the ending pH values, along with a specific treatment procedure; then you have to
select the appropriate chemicals best suited for treatment.
When describing how do starting and ending pH values impact the treatment procedure.
It takes residence or contact time during wastewater treatment for the pH to adjust
appropriately. A very narrow pH range (i.e., 7.0 to 8.0) requires less contact or residence time as
compared to a wider pH range (i.e., 7.0 to 10.0), so the procedure is affected by the required pH
adjustment range. The chemical selection an important consideration in controlling pH.
Different chemicals have varying reaction times, which in turn have a major effect on pH
adjustment and control. Therefore, the equipment residence or contact time is very relevant in
relation to the chemical used for treatment.
The pH virtually no changes immediately. The rate of change depends on chemical
reaction times, which are directly associated with tank volume, the amount of mixing, and all
other aspects of the treatment procedure. Often, the pH can change after wastewater leaves
the treatment tank. In those instances, the reaction time exceeds residence or contact time.
By the way, the process happening here in the pH regulatory tanks is increasing the pH
value of effluent water and there by maintained an optimum pH balance within water. The
chemical used here is burnt calcium carbonate (CaO – Calcium Oxide). The dosage using here is
30kg per 15000 l tank. The water is settle and filtered pumped twice a day towards the regulatory
tank. The water is retained in the tank until the pH value of water is become 6-7 limit. The pH
value checks daily by the factory’s laboratory and decides the period of releasing water.

8. Timely the regulatory tank is collected with Calcium hydroxide residues at the bottom of the tank
and these are removed monthly.
• Biologically Treatment Tanks (Aerobic and Anaerobic bacterial degrading
tanks)
Fats and Oils that exists in very small particles or as some emulsions will not be removed
in reasonable periods of time in primary sedimentation tanks and will remain in the primary
effluent. The Fats and Oils that are not removed in primary treatment will flow to a secondary
treatment unit, such as an activated sludge unit or a trickling filter. The microorganisms in the
secondary biological treatment unit will consume and remove the remaining Fat and Oil. All Fats
and Oil constituents are not removed by the microorganisms at the same rate.
The activity of bacteria should be maintained continuously for the unbroken bio
degradation process. Therefore, the bacteria must be always treated with feed. Twice a day
effluent water is pumped towards these tanks. If not developing pants use cow dung as a
supplement for them. (NMK Agro industries is doing so). The conditions regarding to effluent
water prior to enter the bio treating tanks are,
▪ should be in the (6.5-7.5) Ph range
▪ should be pumped after retained acceptable period in the primary and secondary treating
tanks
The water should be treated in each four tanks for 24 hours period. These oftenly
happens automatically and sometimes manually too. If the bacterial action is so good it can be
identified through several incidents,
▪ always bubbling air bubbles out (carbon dioxide, methane etc)
▪ the appearance of water seen to be more black in colour
▪ a bad odour can be felt
▪ gradually colour, odour and other characteristic features are reducing through tanks
respectively
From the biological treating tanks water passes towards aeration tanks.
In aerobic biological treatment processes. microorganisms (bacteria and higher
organisms) convert the organic matter in waste- water to natural end products such as carbon
dioxide and water and produce more microorganisms. The ability of a compound to be used by
these microorganisms is referred to as biodegradability. Evidence of the removal of organic
matter by microorganisms (biodegradability) can he obtained in a number of ways. The BOD
test is one measure. Observing the removals of a compound in laboratory and research
treatability studies is another.
BOD Biodegradability-The BOD test is a measure of the oxygen used by bacteria to
consume organic matter. The greater the BOD per unit weight of a compound, the greater will
be its biodegradability since a greater fraction of the compound can be utilized by
microorganisms and exert an oxygen demand (BOD). The biodegradability of Coconut oils
measured by the BOD test.

9. Biochemical Oxygen Demand
(BOD, also called Biological Oxygen Demand) is the amount of dissolved oxygen needed
(i.e. demanded) by aerobic biological organisms to break down organic material present in a
given water sample at certain temperature over a specific time period. The BOD value is most
commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of
incubation at 20 °C and is often used as a surrogate of the degree of organic pollution of water.
BOD can be used as a gauge of the effectiveness of wastewater treatment plants.
The test for biochemical oxygen demand (BOD) is a bioassay procedure that measures the
oxygen consumed by bacteria from the decomposition of organic matter. The change in DO
concentration is measured over a given period of time in water samples at a specified temperature.
Chemical oxygen demand (COD)
An indicative measure of the amount of oxygen that can be consumed by reactions in a
measured solution. It is commonly expressed in mass of oxygen consumed over volume of
solution which in SI units is milligrams per liter (mg/L). A COD test can be used to easily quantify
the amount of organics in water. The most common application of COD is in quantifying the
amount of oxidizable pollutants found in surface water (e.g. lakes and rivers) or wastewater.
COD is useful in terms of water quality by providing a metric to determine the effect
an effluent will have on the receiving body, much like biochemical oxygen demand (BOD).
Anaerobic bacteria can be used in the waste water treatment process. Not only the
aerobic bacteria but also anaerobic bacteria are contributing to the biological degrading. There
are two tanks in the factory which are contribute for the anaerobic bacterial degradable.
Types of Bacteria Used in Wastewater Treatment
Bacteria are categorized by the way that they obtain oxygen. In wastewater treatment,
there are three types of bacteria used to treat the waste that comes into the treatment plant:
aerobic, anaerobic and facultative.
Aerobic bacteria are used in most new treatment plants in an aerated environment. This
means that there is dissolved oxygen available for the respiration of the bacteria.
They use the free oxygen in the water to degrade the pollutants in the incoming
wastewater into energy they can use for growth and reproduction. In most cases, the oxygen
has to be added mechanically to the wastewater through the use of aerators in the aerated
section of the treatment plant. With a normal influent load of pollutants, the dissolved oxygen
content in the aerated section of most plants should be kept between 3 and 5 mg/l.
Anaerobic bacteria are normally used in an anaerobic digester to reduce the volume of
sludge to be disposed of and to produce methane gas. This process is completed in anaerobic
conditions, without any dissolved oxygen in the water. The anaerobic bacteria normally get the
oxygen needed for their respiration from their food source. This process is also called
fermentation.
As mentioned above, during the anaerobic digestion process, methane gas is produced
by the anaerobic bacteria. This gas, if properly cleaned and collected, may be used as an
alternative energy source.

10. Another use of anaerobic bacteria is in the biological removal of phosphorus. During this
process, a part of the aeration section of the treatment plant may be made into an anaerobic
zone to facilitate the growth of phosphorus accumulating organisms, which in turn lowers the
amount of phosphorus in the effluent.
Lastly, facultative bacteria are able to change their mode of respiration from aerobic to
anaerobic and back again. These bacteria are able to adapt to either condition, although they
prefer the aerobic condition.
These three types of bacteria are grouped only by their method of respiration. There are many
species of bacteria in a wastewater treatment plant. In a recent study, over 300 species were
identified in an aeration basin. However, they can all be classified as aerobic, anaerobic or
facultative.
Aeration and filtering tank
The volume of the tank is 60 000l. The effluent water which is treated with aerobic and
anaerobic bacteria pumps towards the aeration tank. Then the water in that tank is oxidized
with water twice a day, one hour at once. A powerful motor is used to generate power for that
purpose. Aeration by Oxygen gas contributes to oxidation of water and destroy microorganisms
in the water. Continuous oxidation is done to purify water continuously the step is done
artificially. The water retained here for at least 24 hours. After that the treated water is
released to the natural aeration tank. The water aerates naturally in that tank. Both tanks a net
complex can be found which help to sediment impurities and microorganisms. The nets are
connected with very light regiform (plastic) materials fixed to the bottom of the tanks. The
Inspecting tank
The water which treated to an acceptable level is pumped to this tank. The conditions of
the tank must be appropriate to alive for aquatic lives (fauna and flora). It can be identified
fishes and numerous algae living in the tank. The number of Green algae and ability to living
fauna here are some of the parameters to identify well treated water.
Finally, the water must be suitable to release to the environment. This is checked by
BOD and COD tests in an accredited laboratory. This ETP process inspects monthly by the
Central Environmental Authority. If this procedure running here is wouldn’t be able to fulfill
requirements of the CDA they can’t be continue the process and the factory would have to be
taken corrective measures.
The way of releasing treated water
The treated water releases to an Agricultural land or a water body (canal. reservoir etc).
Sometimes this water uses for agricultural purposes by the farmers during drought periods.
The uses of byproducts of the ETP
• The Oil and Fat collected from settling tanks for Soap industry
• The residues of filtering and settling tanks for Roof tile industry (for seasoning).
• The water for the Agricultural purposes.