The removal rate of Cr⁶⁺ has been explored by the optimized removal conditions. Five Cr-resistant strains were isolated from chromium-contained soil. The most efficient strain S1 was identified as Bacillus subtilis strain SZMC 6179J through 16S rDNA. Response surface methodology (RSM) was used to investigate the effects of four independent variables, including initial pH, initial Cr⁶⁺ concentration (mg/L), time (h) and inoculation percentage (%). RSM revealed that when pH was 5.02, time was 24.0 h, inoculation percentage was 4.64% (v/v) and initial concentration of Cr⁶⁺ was 55.0 mg/L, the optimal condition was obtained. Under the optimum conditions, the actual response values for Bacillus subtilis strain SZMC 6179J was 93.50%. The pH was the most significant factor towards removal rate of Cr⁶⁺. The result showed that the removal mechanism of Cr⁶⁺ by Bacillus subtilis strain SZMC 6179J was reduction under normal conditions. The removal mechanism of Cr⁶⁺ by Bacillus subtilis strain SZMC 6179J was adsorption under adverse conditions.

通过优化去除条件探索了Cr ⁶⁺的去除率。从含铬土壤中分离出 5 株耐铬菌株。通过 16S rDNA鉴定出最有效的菌株 S1 为枯草芽孢杆菌菌株 SZMC 6179J。响应面方法 (RSM) 用于研究四个自变量的影响，包括初始 pH、初始 Cr ⁶⁺浓度 (mg/L)、时间 (h) 和接种百分比 (%)。RSM表明，当pH为5.02、时间为24.0 h、接种率为4.64%（v/v）、Cr ⁶⁺初始浓度为55.0 mg/L时，得到了最佳条件。在最佳条件下，枯草芽孢杆菌的实际响应值SZMC 6179J 菌株为 93.50%。pH值是影响Cr ⁶⁺去除率的最重要因素。结果表明，Cr的去除机理⁶⁺由枯草芽孢杆菌菌株SZMC 6179J是在正常条件下还原。Cr的去除机理⁶⁺由枯草芽孢杆菌菌株SZMC 6179J是在不利条件下的吸附。