PROCESS - FROM 1991 TO 2013

Wastewater treatment was based on a 2-stage process comprising of a Primary & Secondary treatment system. In the Primary Treatment, coarse debris and suspended solids were removed from the wastewater and the remaining dissolved organics were degraded in a biological treatment phase that used a consortia of a bacteria that brought about the wastewater to a condition that was suitable for river discharge

PROCESS - FROM 2013 ONWARDS

With the implementation of the Zero Liquid Discharge System, the Common Effluent Treatment Plant has stopped the discharge of its effluent into the River Palar. The wastewater is treated through a 4-Stage process whereby the water is completely recovered and reused by its member-tanneries and crystalline salt is recovered and stored for safe disposal. The 4-Stage process comprises of the following components -

• Primary Stage
• For removal of coarse debris and suspended solids
• Secondary Stage
• For the degradation of dissolved organics in the wastewater and thereby making it relatively benign
• Based on Membrane Bio Reactor technology
• Tertiary Stage
• Removal of remnant dissolved inorganics and organics and delivering 70% of very clean water that measure up to drinking water standards
• Final Stage
• Evaporation of 30% of the balance of “rejects” in a multiple-effect evaporator for crystallization of the inorganic salts that would go for storage or for possible reuse