生物硫铁生成菌的选育及其在重金属废水处理中的应用

为开发高效经济、环境友好的重金属废水处理技术,采用亨盖特(Hungate)厌氧技术分离出一株产生物硫铁复合材料的硫酸盐还原菌(Sulfate reducing bacteria,SRB),命名为SRB2,并对该菌株进行了生理特性、培养工艺和废水处理研究.菌体杆状稍有弯曲,革兰氏阴性菌,最佳碳源为乳酸钠.pH范围5.0～9.0,最适pH 7.0,最适温度为35℃,培养3 d生物硫铁量和硫化物含量能达最大值,分别为2.85 g L-1、358.048 mg L-1.正交试验结果表明,乳酸钠9.0 g L-1+组合氮源1.5 g L-1+硫酸亚铁10.0 g L-1时生物硫铁产量最高.16S rDNA序列分析表明,菌株与脱硫弧菌属Desulfovibriodesulfuricans strain 734同源性为99%.采用生物硫铁处理重金属Cu2+、Pb2+、Cd2+废水,结果表明生物硫铁能快速处理含Cu2+、Pb2+、Cd2+废水,2 min去除率达99.8%以上.因此,生物硫铁在各类重金属废水处理与重金属废水污染事故应急处理中具有较好的应用前景.

Isolation of a Biological Iron Sulfide Composites-producing Strain and Its Application in Emergency Treatment of Heavy Metal Wastewater

A strain of sulfate reducing bacteria,which could generate biological iron sulfide composites(BISC),was isolated by using Hungate anaerobic technique and named as SRB2.The research on its physiological characteristics and cultivation techniques showed that strain SRB2 appeared as Gram-negative,slightly curved rods,and sodium lactate was considered as the optimum carbon source.The pH range was from 5.0 to 9.0(an optimum pH of 7.0) and the optimum temperature was 35 ℃.The contents of BISC and sulfide reached the maximum values of 2.85 g L-1 and 358.048 mg L-1 on the third day,respectively.The results of orthogonal experiment showed that the optimal medium for generating BISC was sodium lactate 9.0 g L-1,combination nitrogen 1.5 g L-1 and ferrous sulfate 10.0 g L-1.The sequence analysis of 16S rDNA indicated that strain SRB2 was closely related to the type strain of Desulfovibrio desulfuricans strain 734,with 99% sequence similarity.The BISC applied in wastewater treatment could remove heavy metals Cu2+,Pb2+ and Cd2+,with removal rates above 99.8% for 2 minutes.Therefore,great prospects exist for the application of BISC in the emergency treatment of heavy metal contaminated wastewater and heavy metal pollution control.