Simultaneous removal of Cr(VI) and phenol from synthetic binary solution using consortium culture of Bacillus sp. and E. coli immobilized on tea waste biomass in packed bed reactor

Abstract

A continuous bio column reactor was designed for the simultaneous bioaccumulation of Cr(VI) and biodegradation of phenol from their binary synthetic solution with the ratio of (2: 1). Consortium culture of Bacillus sp. and Escherichia coli was immobilized onto tea waste biomass in the packed bed column. The metabolites formed during the biodegradation of phenol by Bacillus sp. were utilized by Escherichia coli for the bioaccumulation of Cr(VI). The considerable effect of empty bed contact time (EBCT), bed height (cm) and flow rate (mL/min) was investigated onto the simultaneous removal of Cr(VI) and phenol in the column reactor. However, after 3-4 days of continuous treatment of Cr(VI) and phenol the effect of these process parameters was not significant. Dissolved oxygen (DO) of effluent has been found to decrease with run time of packed bed column. The pH of the effluent decreased initially for 2 days but after that it became the same as the influent. A mass transfer study was carried out to calculate the pseudofirst-order rate constant for Cr(VI) and phenol, which was in good agreement with experimental results.