Treatment of refinery wastewater usingArthrobacter chlorophenolicusA6 in an upflow packed bed reactor

Abstract

AbstractIn this study, refinery wastewater collected from Guwahati, India, was treated in an upflow packed bed reactor (PBR) with immobilized Arthrobacter chlorophenolicus A6. The wastewater was initially characterized using standard methods. The toxicity of the wastewater was determined using aerobic mixed microbial consortia following the resazurin toxicity assay. As the chemical oxygen demand (COD) level in the raw refinery wastewater was very low (190 mg l−1), the raw wastewater was spiked with a mixture of substituted phenol at different concentrations. The batch shake flask experiment revealed that the COD removal efficiency was found to be less when the raw refinery wastewater was not spiked with nutrient. On the other hand, when supplemented with nutrients in the form of mineral salt medium, more than 98% COD removal was achieved. The PBR was operated by varying the influent phenolic concentration in the range of 250–350 mg l−1 and at a hydraulic retention time of 12.5 h. Results indicated that mo...