Abstract :
Background: Wastewater from various industrial plants such as paper and pulp mills, pigment and textiles can contain various substances that tend to increase chemical oxygen demand (COD) of wastewater. Various agencies like Central Pollution Control Board (CPCB) have placed limits on allowable levels of COD in industrial wastewater effluents. It is desirable to develop a process suitable for treating wastewater to meet the regulatory limits.
Objective: The present study was attempted to solve the problem of high COD values as well as concerned heavy metals like Cu 2 and Cr 6 in industrial wastewater using native bacteria.
Methods: The organic matter that contributed to high COD in wastewater was degraded by native bacterial consortium under aerobic conditions using batch process. Flask treatment experiment was carried out to optimize inoculum size, temperature, pH and HRT using consortium for effective COD, Cu 2 and Cr 6 removals. Lab scale reactor study was carried out in which bacteria were allowed to attach to a supporting matrix to prevent slough off during treatment.
Results: Under the experimental conditions, the reduction efficiencies of COD, Cu 2 and Cr 6 were found to be as high as 57%, 97% and 93% respectively with 72h HRT in fixed film bioreactor.
Conclusion: Use of native biological population for the treatment of industrial wastewater is a permissible and cost effective technique.
Keyword :
Wastewater treatment, COD, Heavy metals, Bio removal, Fixed film bioreactor