A Parliamentary Standing Committee has suggested that an innovative and eco-friendly waste water treatment technology developed by Indian Agriculture Research Institute (IARI), Pusa, should be widely used for sewage treatment.
The Water Technology Centre (WTC) of IARI, which is engaged primarily in efficient use of water resources in agriculture, has developed an eco-friendly sewage water treatment plant in the IARI Delhi premises using ‘Typha latifolia’ (a wet land Plant).
The facility is spread over 1.42 hectares and is capable of treating 2.2 million liters of sewage per day from the Krishi Kunj Colony, at a cost of approx. Rs 1.2 crore and with a potential to irrigate 330 acres of IARI farmland. The eco-friendly sewage treatment plant (e-STP) has 3-treatment cells (of 80 meter by 40 meter dimension each) and ensures complete gravity flow of the wastewater from the sewage wells to the treated water containing cell of the system.
The noteworthy feature of this facility is that the environmental stress is 33 times lesser than that of a conventional sewage treatment plant (STP) and output ie treated water is associated with significantly lower turbidity, BOD, Nitrate, Phosphate, lead, Iron, Nickel and Sulphate.
Compared to the conventional wastewater treatment systems, the IARI’s wastewater treatment technology requires just 1 per cent energy; zero-chemical application; zero-sludge generation; 50-65 per cent reduced treatment cost and no skilled manpower requirement. To top it all, it has an integrated business model by utilising system biomass harvested from wetland, which can be transformed to particle board thereby making the complete model self-sustainable. It is, therefore, aptly called “Cash from Trash” business model.
There are 269 sewage treatment plants (STPs) in India, of which only 231 are operational. Further, nearly 39 percent of the STPs are not conforming to the general standards prescribed under the Environmental (Protection) Rules for discharge into streams.
According to a report, the estimated sewage generation from Class I cities and Class II towns (as per estimation made for the year 2008) is 38,254 million litres per day (MlD). Against this, there exists only 11,787 MlD treatment capacity. Therefore, existing treatment capacity is just 30 percent of present sewage generation.
The Parliamentary Standing Committee, in its latest report, said the existing system of Sewage Treatment Plants (STPs) is highly expensive and creates tonnes and tonnes of sludge which is piling up in the cities.