硫酸盐还原颗粒污泥对Cr的吸附机理解析

以硫酸盐还原颗粒污泥作为研究对象,进行Cr的吸附容量研究及吸附等温线拟合,测定颗粒污泥中的硫化物含量、对比实验前后颗粒污泥的表面形态和微生物组成并采用傅里叶红外变换光谱(FTIR)分析颗粒污泥的表面基团。结果表明,颗粒污泥对Cr的吸附容量为6.84 mg/g,吸附过程可用Langmuir吸附等温式描述。颗粒污泥中硫化物含量达9.868 mg/g(湿重),对应每克颗粒污泥对Cr的最大吸附量可达10.69 mg;颗粒污泥表面生长大量的微生物,以杆菌为主,颗粒污泥表面丰富的微孔结构及微生物所分泌的胞外物均可有效吸附溶液中的Cr;FTIR分析结果显示,颗粒污泥中包含大量C=O、C-N及-S等基团,这些基团均可通过与C(rⅥ)或C(rⅢ)之间的静电吸附作用吸附溶液中的Cr。研究表明化学与生物吸附作用在硫酸盐还原颗粒污泥吸附溶液中的Cr过程中起到了重要的作用。

Mechanism of Cr Adsorption by Sulfate Reducing Granular Sludge

Cr adsorption experiment was done with sulfate reducing granular sludge as the study objective.Adsorption capacity,adsorption isotherm,sulfide concentration,surface morphology,microorganism composition and surface group of sulfate reducing granular sludge were studied.Results indicated that the adsorption capacity was 6.84 mg/g,and the process fitted Langmuir isotherm well.Sulfide concentration of sulfate reducing granular sludge was 9.868 mg/g(wet weight),the adsorption capacity of Cr with sulfide was 10.69 mg/(g granular sludge).Mass microorganism lived on the surface of sulfate reducing granular sludge,most were Bacillus,and the polyglucose,protein and amide secreted by microorganism would enhance the adsorption of Cr.Analysis with FTIR revealed a large number of surface group including C=O,C-N and-S,all of them could adsorb Cr by electrostatic chucking with Cr(Ⅵ) and Cr(Ⅲ).Studies showed that chemical and biological adsorption would play an important role in Cr adsorption by sulfate reducing granular sludge.