硫酸盐还原菌混合菌群胞外聚合物对Cu^(2+)的吸附和机理

COPPER(Ⅱ) SORPTION BY EPS OF MIXED SRB POPULATION AND MECHANISM

生物吸附法是处理含重金属废水的一种新兴的处理技术。微生物所分泌的胞外聚合物(EPS)在微生物吸附重金属中起重要作用。硫酸盐还原菌(SRB)混合菌群分泌的EPS能有效的吸附水溶液中的Cu2+,Langmuir等温方程和Freundlich等温方程都能拟合实验所得吸附数据,最大吸附容量达到478.47mg/gEPS。水溶液的初始pH值对EPS吸附Cu2+影响明显,在pH为7时,吸附效率最高,pH增减,吸附效率明显下降。SRB混合菌群分泌的EPS的FT-IR分析表明,EPS对Cu2+的吸附主要在于EPS中的蛋白质的酰胺(Ⅱ)、羧基、多聚糖的C-O-C、-OH和脂类等基团对Cu2+的强络合能力。

Biosorption is an emerging technology treating wastewater containing heavy metals. The extracellular polymeric substances（RPS） excreted by microbes plays an very important role in biosorption of heavy metals. This study showed that EPS of mixed sulfate-reducing bacteria （SRB） was effective in sorbing Cu^2＋. The Langrnuir Isotherm Model and Freundlich Isotherm Model could describe the experiment data and the maximum sorption capacity was up to 478.47mg/gEPS. The initial pH value of solution had apparent influence on Cu^2＋ sorption by EPS. When pH was 7, EPS was most effective in adsorbing Cu^2＋ and as pH increased or decreased, sorption efficiency decreased significantly. FT-IR analysis demonstrated that the groups of hydroxyl, carboxyl and amide（ Ⅱ ） were involved in binding Cu^2＋.