ROURKELA, JANUARY 10, 2022
As a part of its commitment to the cause of environment, Rourkela Steel Plant (RSP) has been making every effort to reduce, treat and reuse its effluent water. Besides, the Steel Plant is currently implementing various projects to achieve the objective of becoming a ‘Zero Discharge’ Plant.
RSP has adopted a multi-stage treatment strategy for treating its waste water before discharging into River Brahmani. The waste water generated from various units of RSP is first treated at their source of generation in the dedicated Waste Water Treatment Plants (WWTP) installed at different departments. The treated effluent is then discharged to ‘Guradhi Nallah’ through 9 outfalls. The total effluent is then taken to a ‘Lagoon’ which is an Oxidation Pond for secondary treatment. RSP has constructed a shallow oxidation pond called Lagoon spread over 52 hectares of land which was designed and constructed under the guidance of NEERI, Nagpur. The water is retained in the lagoon for 4-5 days during which the pollutants are treated naturally by photochemical reaction in presence of aerobic and facultative bacteria. After treatment the water is discharged into River Brahmani through Lagoon outlet. The quality of finally treated water discharged into the river is well within the statutory norms in all the times.
Work is now going on in full swing to desilt the lagoon by evacuation of 3 lakh cubic metre of silt using dredging/mechanical excavation. After desilting of the Lagoon, there will be a clear water body spreading over an area of around 20 hectares which will add to the biodiversity and aesthetics. The project being implemented at a cost of Rs. 23 crore is expected to be completed this year.
Additionally, RSP has also adopted Biological treatment in BOD Plant for Coke Oven effluent. The treated water from BOD Plant is recycled back to Coke Ovens for its utilization in coke quenching. At present, Modernisation of BOD Plant on ZLD concept is also in progress. The project is being executed at a cost of Rs. 34 crore, and is likely to be completed this year.
Besides, a Sewage Treatment Plant (STP) is being installed at the Outfall #7 that handles the discharged water from canteens, washrooms and toilets. This project being executed at an expenditure of Rs. 15 crore, too is planned to be completed in the current year.
Another project under implementation is the ‘Total treatment of effluent coming from Outfall#1.’ Under this scheme, the total effluent coming out from the Steel Melting Ship-2 and channeled through Outfall #1, will be treated in a dedicated Waste Water Treatment Plant with latest technology viz., HRSCC and RO systems so that the quality of the treated water can match with makeup water. This water will be reused in the steel making process.
The 3-Million Ton Hot Strip Mill that is in the process of stabilization, functions entirely on Zero Liquid Discharge concept. The Mill lifts water from the lagoon and uses it after recycling the same. All the equipments are designed to reuse this water so that there would not be any liquid discharge from this state-of-the-art unit.
Notably, RSP conducts regular monitoring of the final effluent discharged from the Lagoon outlet to River Brahmani. Besides a Continuous Effluent Quality Monitoring Station has been installed at the Lagoon outlet which continuously analyses the effluent quality and the measured parameters are uplinked with the server of State Pollution Control Board, Odisha.