玉米秸秆生物炭固化细菌对镉砷吸附

Adsorption of Cadmium and Arsenic by Corn Stalk Biochar Solidified Microorganism

为了确保细菌对镉砷复合污染土壤的修复效果,对细菌进行固定化处理.本研究将细菌悬液(Delftia sp.B9,B9)、玉米秸秆生物炭(corn stalks biochar,CSB)以及玉米秸秆生物炭-细菌复合体(corn stalks biochar-bacteria complex,B-CSB)作为3种吸附材料,探究3种材料对镉和砷的吸附特性及pH对3种材料去除水中镉砷离子性能的影响,进行了等温吸附模型拟合,并采用扫描电镜(SEM)、傅里叶红外变换光谱(FT-IR)和X射线光电子能谱分析(XPS)对3种材料进行表征分析,同时探究添加B9、CSB和B-CSB对土壤中镉和砷形态变化的影响.结果表明,3种材料对Cd^2+的饱和吸附量分别为49.43、82.68和75.38 mg·g^-1;对As的饱和吸附量分别为24.67、42.92和34.03 mg·g^-1.添加B-CSB可使土壤中的弱酸可溶态Cd显著下降,残渣态Cd显著增加;铁型砷含量显著减少,残渣态砷含量增加.B-CSB是一种更有效地修复镉砷复合污染的材料.

Immobilization of bacteria on biochar can improve the performance of the soil complex polluted with cadmium(Cd)and arsenic(As).In this study,bacteria(Delftia sp.B9,B9),biochar(corn stalks biochar,CSB),and biochar-bacteria complexes(B-CSB)were used as adsorption materials to explore the adsorption characteristics of Cd and As.The effects of pH on the adsorption performance of Cd and As and the ion removal from the aqueous solution were investigated,and the adsorption behaviors were simulated using an isothermal adsorption model.The changes in Cd and As speciation with the addition of B9,CSB,and B-CSB to As and Cd-contaminated soil were explored.The results showed that the Cd-saturated adsorption capacities of B9,CSB,and B-CSB were 49.43,82.68,and 75.38 mg·g^-1,respectively;the As-saturated adsorption capacities were 24.67,42.92,and 34.03 mg·g^-1,respectively.The concentration of available Cd and As significantly decreased,whereas the residual fraction increased after the addition of B-CSB.B-CSB was shown to be an effective material for the remediation of soil complexes polluted with Cd and As.