黑曲霉产酸淋滤去除污染土壤中的重金属

Removal of heavy metals from contaminated soils using organic acids produced by Aspergillus niger

研究了利用黑曲霉产酸淋滤去除污染土壤中重金属的生物修复过程.在不同土壤和培养基比(w/v)5%,10%,20%情况下,添加黑曲霉的蔗糖和矿物盐培养基以产生有机酸,淋滤去除污染土壤中重金属.结果表明,一步生物淋滤修复过程中,当固液比为5%、修复时间为7d时,冶炼厂土壤中Cu、Cd、Pb和Zn去除率分别为25.2%,98.3%,30.2%,15.7%;张士灌区污染土壤中Cu、Cd、Pb和Zn去除率分别为27.1%,36.8%,0%,7.6%.二步生物淋滤修复过程中,当固液比为10%、修复时间为9d时,冶炼厂土壤中Cu、Cd、Pb和Zn的去除率分别为67.4%,86%,23.3%和7.6%;张士灌区污染土壤中Cu、Cd、Pb和Zn的去除率分别为55.2%,85.7%,7.8%和18.1%.

Bioleaching process developed using fungus Aspergillus niger to produce organic acids for leaching of heavy metals from contaminated soils. Sucrose and mineral salts medium were used to produce organic acids at various pulp density （5%, 10%, 20%, w/v）. During one-step bioleaching process, at 5% （w/v） of pulp density and 7d of leaching time, 25.2% of Cu, 98.3% of Cd, 30.2% of Pb, 15.7% of Zn were removed from Shenyang Smelting Plant soil, and heavy metal removals of Cu 27.1%, Cd 36.8%, Pb 0% and Zn 7.6% were obtained from Zhangshi Irrigation Area soils, respectively. During two-step bioleaching process, at 10% （w/v） of pulp density and 9d of remediating time, 67.4% of Cu, 86% of Cd, 23.3% of Pb and 7.6% of Zn were removed from Shenyang Smelting Plant soils, and 55.2% of Cu, 85.7% of Cd, 7.8% of Pb and 18.1% of Zn were removed from Zhangshi Irrigation Area soils, respectively.