NAGPUR: Waste Water Treatment Technology Division (WWTTD) at the National Environmental Engineering Research Institute (Neeri) has developed a technology to treat wastewater generated from chemical industries. This technology has proved to be extremely effective in removing organic pollutants.

Nandesari Industries Association (NIA) near Baroda in Gujarat has already set up a treatment plant of 5 million litres per day (MLD) capacity with 26 reactors for a cluster of over 280 industries at cost of Rs18 crore based on this technology.

Neeri director SR Wate told TOI that the 'electro oxidation technology' is being used in a common effluent treatment plant (CETP) for the first time in the country. "It is real achievement for Neeri which had been on the job for 5-6 years. The success of the pilot plant motivated the industries association to scale up the technology and set such a huge plant," he said.

WWTTD senior principal scientist NN Rao, who headed the team which developed the technology, tells that since industrial wastewater is highly non-biodegradable it was a difficult task. "But I took it as a challenge and finally managed to develop such a big scale plant with support from NIA engineers," he said.

NIA did have CETP until the setting up of this plant, but the treatment was not enough as per standards. The area has mainly pesticides, textile dyes, nitro-compounds, chloro-organic compounds and pharmaceutical industries. The chemical oxygen demand (COD) levels of the CETP treated water should not exceed 250mg/lit but this figure was 33-38,000.

The treatment process involves three steps. The first two conventional steps, removal of suspended solids using lime-based settling process and filter press technology which removes very fine colloidal particles are followed by the Neeri technology which is based on the principle of electrochemistry. "Major advantages of this technology are its environmental compatibility, operations at room temperature, atmospheric pressure, amenability to automation. There are no solid residues. Also it is a complementary and complete treatment. It also enhances the bio-degradation process," said Rao.

NIA presented Neeri with a 'Technical Excellence Award' recently. NIA chairman and president Babubhai C Patel told TOI that the NIA transports its wastewater 50km into the Gulf of Khambat in Arabian Sea. "I had read an article on similar work by Neeri in a journal and I contacted the institute in 2006. Since then Neeri has been working on the subject under two sponsored projects and developed this technology," he said.

