1). Pretreatment in individual tanneries
The existing pretreatment system in individual tanneries consists of the following units :
- Screen chamber with screens
- Collection tank
- Pumps
- Electromagnetic flow meter
The PTIETC CETP monitor the effluent discharges through the electro-magnetic flow meter and other portable monitoring instruments.
2). Effluent collection and conveyance
- The tanneries discharge the effluent after pretreatment through common HDPE pipe line to the collection wells cum pumping stations located in 7 zones. The total length of the pipeline network is about 8 km.
- The CETP is located in a mixed agglomeration of industries, residential and other activities. Due to the recent relaying of roads and public drainage works, the old pipes laid for effluent conveyance in the Pammal / Pallavaram area covering 144 units and CETP are proposed to be re-laid and updated in required locations.
- The pollution load in terms of BOD, COD, SS have been reduced by about 60-70% and the TDS and chlorides have been reduced by more than 70%. The TDS level during the period 2000-2005was reduced to 8000mg/l.
- The quality of ground water improved in Pallavaram/ Pammal area due to stoppage of raw to semi finish operation. Due to the use of quality water in the semi finish to finishing operations, the TDS level is further reduced from 8000mg/l to the current level of 4500mg/l – 5500mg/l. The current TDS level in the effluent discharged from the Pallavaram tanneries and PTIETC CETP is the lowest among all the CETPs in Tamilnadu and as well as in whole of India.
