Abstract：This study was aimed to investigate the bio-dissipation mechanisms of 2,4,4′-trichlorobiphenyl (2,4,4′-TCB, PCB28) by Ensifer adhaerens, and explore the variation of the biosorption and biodegradation with the changes of time, pH, temperature, optical density, metal ions (Ca2+、Mg2+). The removal mechanism of 2,4,4′-TCB by dead E. adhaerens was biosorption, the adsorption efficiency reached a plateau after 2h incubation,which was 85.97%. Both biosorption and biodegradation contributed to the removal of 2,4,4′-TCB by live E. adhaerens in water, and in this experimental period biosorption was dominated. The adsorption efficiency and degradation efficiency were 60.59% and 12.90% respectively. The highest adsorption efficiency of live strain was occurring at pH of 6.0, temperature of 35℃, OD of 0.8, cell pretreated with 1mol/L metal ion. The optimal degradation efficient of live strain was under the condition of 7.5pH, 30℃, biomass pretreated with 0.05mol/L metal ion.
