The accumulation of heavy metals by microbial biomass with high surface area-to-volume ratio holds great potential for heavy metal removal in both soluble and paritcular forms, especially when the heavy metal concentrations are low (＜ 50 mg/L). E. coli and B. subtilis are effective agents for metal removal. We further investigated the effect of pH, temperature, equilibration time, and pre-treatment reagents on the removal of Pb( Ⅱ ), Cd( Ⅱ ) and Cr( Ⅵ ) from aqueous solutions by E. coli and B. subtilis. E. coli and B. subtilis were cultivated for 60 hours, the experimentally determined optimal cultivation time before they were used in metal removal experiments. Under the optimal conditions of pH 6.0, equilibration temperature 30 ℃ and equilibration time 1 hour, 63.39 % and 69.90 % Cd( Ⅱ ) can be removed by E. coli and B. subtilis. Under the optimal conditions of pH 5.5, equilibration temperature 30 ℃ and equilibration time 1 hour, 68.51% and 67.36% Pb( Ⅱ ) can be removed by E. coli and B. subtilis. And under the optimal conditions of pH 5.5, equilibration temperature 30 ℃, and equilibration time 1 hour, 60.26% and 54.56% Cr( Ⅵ ) can be removed by E. coli and B. subtilis. Chemical treatment of cultivated bacteria (0.1 mol/L NaOH, 0.1 mol/L, HCl, 30% ethanol, and distilled water) affects the efficiency of metal removal by E. coli and B. subtilis. Pretreatment of biomass by NaOH enhanced Cd( Ⅱ ), Pb( Ⅱ ) and Cr( Ⅵ ) removal, while pretreatment by HCl, ethanol and distilled water reduced Cd( Ⅱ ), Pb( Ⅱ ) and Ct( Ⅵ ) removal. For metal removal from industrial waste discharges, pretreated biomass of E. coli can remove 68.5 % of Cd and 58.1% of Cr from solutions, while pretreated biomass of B. subtilis can remove 62.6% of Cd and 57% of Cr from solutions.