硫酸盐还原菌去除铅的实验研究

Experimental Studies on the Removal of Lead by Sulfate- reducing Bacteria

考查了初始p H值、反应温度、接种量等对硫酸盐还原菌菌株的生长和对重金属铅去除效果的影响,应用X射线衍射(XRD)、表面能量色谱分析(EDS)对沉淀物进行了表征。结果表明,该菌株生长及去除铅的最佳条件为:p H=8.0,温度30℃,接种量10%,该条件下的去除率高达99.79%。所得到的沉淀物为硫化铅,立方方铅矿结构,结晶度良好。进一步研究了最佳条件下不同初始浓度硝酸铅对硫酸盐还原菌细胞中亚硫酸盐还原酶(SiR)和腺苷酰硫酸还原酶(APS)比活力的影响。结果表明,硝酸铅质量浓度低于950mg/L时,亚硫酸盐还原酶和APS还原酶比活力受到轻微抑制,当硝酸铅质量浓度为1 100 mg/L时,其比活力受到明显的抑制。重金属铅对亚硫酸盐还原酶比活力抑制作用相对明显。

The influences of the initial pH value, reaction temperature, inocuhim amount on the growth and the removal ef- fect on lead of Sulfate - reducing bacteria strain were investigated. Moreover, the precipitates were characterized by means of XRD and EDS. The experimental results indicated that the optimum conditions for the growth of stain and the removal rate for lead ion were： pH = 8.0, temperature at 30 ℃, inoculation amount of 10%, reaching 99.79%. The precipitates was lead sulfide, with a good degree of erystallinity. Under the optimal removal condition, the reason why different initial con- centrations of Pb2 ＋ have different effects on the specific activities of sulfite reductase and APS reductase in Sulfate - reducing bacteria strain were studied, the results showed that： when concentration of lead nitrate was less than 950 mg/L, the specif- ic activity of sulfite reduetase and APS reduetase were slightly restrained, While the specific activity was significantly re- strained by 1 100 mg/L of lead nitrate, the inhibitory effect of lead on the specific activity of sulfite reductase was relatively obvious.