Biodegradation and Kinetic Study of 4-Chlorophenol in Bioreactor Packed with Stabilized Bacteria Entrapped in Calcium Alginate Beads System

Abstract

Chlorophenols (CP) are listed as priority pollutants both by US EPA as well European community. In the present study, biodegradation of 4-CP was investigated using a cells immobilized in calcium alginate beads system. The batch shake flask study of the cells entrapped in calcium alginate beads system followed substrate inhibition kinetics. The bio-kinetic constants that are necessary to design and simulation of the bioreactor system were estimated from the best fitted Edward model. Further, performance of the cells immobilized in calcium alginate beads system for the degradation of 4-CP was evaluated in an upflow packed bed reactor (PBR) by varying its influent concentration from 100 to 250 mg/L and hydraulic retention time (HRT) between 8 h and 2 h. Almost complete removal of 4-CP and 98.6% effluent toxicity removal were obtained in the reactor at a 4-CP loading rate of 1275 mg/L/d or lesser. However, at higher 4-CP loading rates, the performance of the packed bed reactor (PBR) was found to be deteriorated due to the temporary accumulation of 4-chlorocatehol. The study reveals the potential of cells entrapped in calcium alginate beads system for biodegradation of 4-CP from contaminated wastewater.