Effluent treatment by reverse osmosis21 May 2002
Despite connecting their facilities to individual or common effluent treatment plants, the tanners of Vellore were unable to meet the TDS (total dissolved solids) of 2,100 parts per million prescribed by the Tamil Nadu Pollution Control Board. Leather units located on the Palar River basin in Vellore district are awaiting the implementation of pilot projects using reverse osmosis (RO) for dealing with the problem of TDS in treated tannery effluent. According to M M Hashim, chairman of the environmental arm of the All India Skin & Hide Tanners & Merchants Association (AISHTMA), the focus of the efforts to get rid of the TDS problem has now shifted to RO technology. It was decided that this technology would be tested in two pilot projects funded by the government and the industry. The focus has shifted from the two alternatives considered earlier for dealing with the TDS problem to the RO option, according to Hashim. The first option being discussed was for a pipeline along the Palar River bed to direct the treated effluent for discharge into the sea. The second option was for the tannery clusters around Ambur. This project, which has been sanctioned for funding from the National River Conservation Programme of the Union Ministry of Environment and Forests (MoEF), involves laying sewerage lines in the town so that the treated tannery effluent can be mixed with treated sewage. Despite connecting their facilities to individual or common effluent treatment plants, the tanners in Vellore district were not able to meet the TDS of 2,100 parts per million, as prescribed by the Tamil Nadu Pollution Control Board. Currently, the TDS values they achieve post-treatment are at least three to four times higher. Hashim said the tanneries would soon start paying the compensation as laid out under the Award of the Loss of Ecology Authority. The tanneries of Vellore district were asked to pay Rs26.82 crore as compensation.