Conventional treatment of liquid waste generated in the tanning process is able to produce treated water complying, in general, with all prescribed pollution control norms, except those relating to Total Dissolved Solids (TDS), chlorides and sulphates. In other parts of India as well as in many foreign countries, dilution of TDS in the treated waste water is achieved by combining it with domestic sewage for further treatment. Alternatively, marine discharge of such treated effluent is permitted. However, the tannery districts of Tamil Nadu are located far from the coastal areas and there are no sewage treatment plants in the neighbourhood of such places. As a result, the TNPCB has mandated that tanneries as also other industries like textiles (also generating waste water high in TDS) should establish such treatment systems which will completely prevent discharge of even a drop of waste water. This has necessitated ETPs / CETPs in Tamil Nadu to go in for the expensive and sophisticated RO (Reverse Osmosis) technology followed by evaporation for evaporating the reject of RO and collecting salt as solid waste to be fully either reused or safely disposed.
As stated supra, due to the proactive role and administrative compulsion of the Tamilnadu Pollution Control Board vis-a-vis the Courts directions, the leather industries in Tamilnadu has the Hobson's choice of either implementing the ZLD and surviving in the field or to exit the field. The ZLD is an unique project in the sense that nowhere in the world or in other States in India, the ZLD project is implemented in leather industries. Still the industries in Tamilnadu, in the circumstances explained above, have to per force implement the project. The implementation of ZLD is a very costly preposition. In order to mitigate the hardship on the tanners, the DIPP, MoC&I, GoI came forward to extend grant to the extent of 50% of the capital cost and the GoTN, on its part, offered 15% of the capital cost as grant. The remaining 35% of the capital cost plus any cost excess is to be contributed by the beneficiary.
The project-wise details, with the latest stage of implementation and the target date for completion are presented. |
