Effluent is generated in many manufacturing industries like textile, pharmaceuticals and chemicals, tanneries etc. Contaminated water cannot be released without treatment as it contains toxic and non-toxic chemicals. Releasing it may cause contamination of the existing pure water and will affect the environment. As a result ETP’s are installed in most manufacturing industries.
The Effluent treatment plants (ETP) are used for the removal of high amounts of organic compounds, debris, dirt, grit, pollution, toxic, non-toxic materials and polymers etc. from industrial effluent. The ETP plants use evaporation and drying methods and other auxiliary techniques such as centrifuging, filtration, incineration for chemical processing and effluent treatment.
ETP Plant Operation
1. Screen Chamber:-
- This chamber removes relatively large
solid to avoid abrasion of mechanical equipment and clogging of hydraulic
system.
2. Collection Tank:-
- The collection tank collects the
effluent water from the screening chamber, stores and then pumps it to the
equalization tank.
3. Equalization Tank:-
- The effluents do not have similar
concentration at all the time; the pH will vary time to time. - Effluents are stored for up to 8 to
12 hours in an equalization tank resulting in the homogenous mixing of
effluents and helping in neutralization. - Continuous mixing also eliminates
settling of solids within the equalization tank. - Reduces SS, TSS.
4. Flash mixer:- Coagulants are added to the effluents:
- Lime:(800-1000 ppm) To correct the pH
upto8-9 - Alum: (200-300 ppm) To remove colour
- Poly electrolyte: ( 0.2 ppm) to
settle the suspended matters and reduce SS, TSS.
The addition of the above chemicals by efficient rapid mixing facilitates homogeneous combination of Flocculates to produce micro flocks.
5. Clariflocculator-
- In the Clariflocculator the water is
circulated continuously by a stirrer. - Flocculation provides slow mixing
that leads to the formation of macro flocs, which then settles in the clarifier
zone. - Overflowing water goes out to the
aeration tank. - The solid particles settle down, and
are collected separately; this reduces SS, TSS. - The settled solids i.e. primary sludge
is pumped into sludge drying beds.
6. Aeration Tank:-
- The effluent after clarification
flows to an aeration tank for aerobic treatment. - This tank is equipped with air
blowers or diffusers using which air is passed through the tank. - This air is required to maintain the
desired dissolved oxygen (DO) level required for bacteria to grow and remove
BOD and COD by breaking down the matter. - BOD and COD values of effluent are
reduced up to 90%.
7. Secondary Clarifier:-
- The overflow from aeration tank is
led into the secondary clarifier where solid liquid separation takes place. - The settled solids in secondary
clarifier are called biological sludge, a part of which is recycled back into
the aeration tank to maintain the desired MLSS level and remaining sludge is
conveyed to sludge collection tank for further treatment. - The outlet water quality is checked
if it’s within the accepted. - The treated water is disposed through
pipelines.
8. Sludge Thickener:-
- The inlet sludge consists of 60%
water + 40% solids. - The effluent is passed through a
centrifuge. - Due to centrifugal action, the solids
and liquids are separated. - The sludge thickener reduces the
water content in the effluent to 40% water + 60% solids. - The effluent is then reprocessed and
the sludge is collected at the bottom.
9. Drying Beds:-
- #Primary and secondary sludge is dried on the drying beds to further reduce the water content. Alkin water is one of the best effluent treatment manufacturers in India and across the globe. In case of any queries feel free to reach us by filling the inquiry form on Contact Us page. We will get back to you within 24 hours.