Study of Impact on Noyyal River and Orathupalayam Dam due to Effluent Discharge by the Textile Dyeing Industries in Tiruppur, Tamil Nadu and its Remediation Measures

摘要

The Noyyal river is a tributary of the river Cuavery. Tiruppur town is located on the bank of Noyyal river. There 729 bleaching and dying units are in operation in Tiruppur area. These units generate 96.1 million L/day (MLD) of wastewater. Initially, they discharged untreated effluent into the river. After the Tamil Nadu Pollution Control Board (TNPCB) directions they installed 8 common effluent treatment plants (CETP) consisting of physical, chemical and biological treatment process. Even then, the treated effluent from the CETPs did not meet the total dissolved solid (TDS) and chloride standards. The discharge of high TDS and chloride effluent into Noyyal river had significantly affected the river water quality, ground-water quality as well as the Orathupalayam dam which is constructed across Noyyal river at 32 km down stream of Tiruppur. In year 2006, the Hon'ble High Court of Madras and TNPCB directed the bleaching and dyeing units to install zero liquid discharge (ZLD) plant consisting of RO plant and reject management system. At present there are 17 CETPs with ZLD plant are in operation. The treated effluent is reused by the member units. The RO reject is concentrated in multiple effect evaporator (MEE) / mechanical vacuum re-compressor (MVR) and then solar evaporated. Thus the discharge into the river is now stopped. Orthuapalayam dam is partly desilted. However, the damage caused to the groundwater and soil in the river basin is yet to be restored.