Performance of UASB reactor in the biotreatment of 1,1,2-Trichloroethane

Abstract

This article aims to examine the performance of bench-scale Upflow Anaerobic Sludge Blanket (UASB) reactor operated under varying operating conditions, during the treatment of simulated wastewater containing 1,1,2-Trichloroethane (TCA). Initially, reactor R1 (control) and reactor R2 (test) containing TCA were operated at 5 different Hydraulic Retention Times (HRTs) of 36, 30, 24, 18 and 12 hours. TCA removal decreased from 99.8% to 96.5%, when the HRT was reduced from 36 to 12 hours in discrete steps. Later, when the OLR was varied periodically from 1.5 to 3.1 kg COD/m³.d to obtain a different substrate: co-substrate ratios; lower TCA removal efficiencies were observed at an OLR of 2.5 kg COD/ m³.d and above. The average effluent concentrations of TCA and COD were 0.12 and 79 mg/L, respectively, at the optimum HRT of 24 hours; whereas the effluent TCA and COD concentrations at the substrate: co-substrate ratio of 50:1 was 0.06 mg/L and 48 mg/L, respectively.

Keywords:

• Upflow anaerobic sludge blanket
• industrial wastewater
• 1,1,2-Trichloroethane (TCA)
• upflow velocity
• organic loading

Acknowledgments

The authors would like to take the opportunity to thank Dr. Sudhir K. Gupta, Professor (retired), Centre for Environmental Science and Engineering, Indian Institute of Technology (IIT) Bombay, for his contributions in the formulation of this research problem and keen interest in developing this work. Also, the guidance and help extended by the staff of Sophisticated Analytical Instrumental Facility (SAIF), IIT Bombay, is thankfully acknowledged.