Effluent from member tanneries subject to pre-treatment such
as screening and
sedimentation prior to discharge into Common Wastewater Conveyance Collection system leading to
7 Zonal Pumping stations. Electromagnetic flow meter is provided in each member tannery unit for
monitoring. Zonal pumping stations are being upgraded by providing suitable Mechanical Rack Screen
and safety measures to avoid chocking problems. From Zonal Pumping stations effluent discharged
through HDPE pipelines to inlet chamber of CETP.
PHYSIOCHEMICAL / BIOLOGICAL SYSTEM
Physiochemical treatment removes 25-30% of BOD, 35-45% of COD,
80-90% of the Suspended Solids (SS) and almost all residual chromium. Biological treatment removes
about 95% of BOD and about 90% of COD.
TERTIARY TREATMENT AND REVERSE OSMOSIS SYSTEM
Tertiary treatment units such as Dual Media Filter (DMF), Ultra-Filtration (UF) reduce the residual BOD,
COD & SS and make the effluent fit for RO system. RO system is used for recovery of quality water for
reuse by the member tanneries. Tertiary treatment units are being periodically upgraded and Advanced Oxidation
System of Ozone Treatment is being implemented under the current upgradation of CETP to remove the colour
and residual non-degradable COD. Ozone treatment is being first of its kind in World Leather Sector.
TDS MANAGEMENT SYSTEM
The treated effluent after Advanced Oxidation System will be pumped
through new treated effluent conveyance system from PTIETC CETP to Perungudi Sewage Treatment Plant (STP)
for Mixing/Dilution with treated domestic sewage at Perungudi STP for TDS Management. This project component
is being implemented through Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) as per the
direction and guidelines of Tamilnadu Pollution Control Board (TNPCB) with technical & financial support
from CSIR-CLRI, DPIIT-GoI, MSME, GoTN and first of its kind.