Decentralised wastewater treatment system at AAETI, Nimli

Date: October 30, 2020

Location: AAETI, Nimli
Scale: Institute
Implementing organisation: CSE, New Delhi
Designed Capacity: 8 KLD
Area : 80 m2
Operational since :2017
Capital cost : Rs. 8 Lakhs
O&M: Expected to be between Rs. 40-60 thousands
The Anil Agarwal Environmental Training Institute (AAETI), covering 10 acres (4.04 hectares) in Nimli village, Tijara block, Alwar District in Rajasthan, is a fully residential institute for training and capacity building. This training institute is neither connected to municipal water supply nor to sewerage network. In order to reduce the dependence and save precious ground water source, the effort was made to construct DWWTs and use the treated effluent in non-potable purpose such as irrigation.
The system consists of two chambered settler, five chambered anaerobic baffled reactor (ABR), planted gravel filter (PGF) bed and polishing pond. Wastewater generated from the academic block feed into the settler where the sedimentation process removes the settlable solids. The effluent from the settler is conveyed to ABR with two filter chambers, where anaerobic degradation process by microorganism is designed to reduce upto 90% of the BOD. Further, the outlet of ABR is fed into PGF bed through an inlet chamber for tertiary treatment. The bed of PGF consists of crushed stones and on the top of it Canna indica plant is grown for removal of nitrogen and phosphates. The bottom of the PGF bed is designed with 1% slope, which ensures treated water to flow towards polishing pond without any pumping. The polishing pond removes pathogen and odor with the help of natural aeration and sunlight. The final treated water will be pumped for horticulture purpose.
The system is expected to provide treated water that would be used for horticulture purposes to maintain green area of 0.5 Acres. This would help in saving about 8000 litres of fresh water. Water quality report at the inlet and outlet of the DWWTs will be furnished in due course.

Water Programme
Centre for Science and Environment