污泥基生物炭的制备及其对Hg~(2+)的吸附

在添加乙酸钾的条件下将污泥低温热解制备出污泥基生物炭,并将其用于溶液中Hg~(2+)的吸附,考察了Hg~(2+)吸附效果的影响因素,并对吸附机理进行了分析。表征结果显示:热解对污泥有一定的造孔作用,而乙酸钾对孔隙结构的形成影响更大。实验结果表明:在吸附温度为25℃、溶液p H为6、初始Hg~(2+)质量浓度为15 mg/L、污泥基生物炭投加量为6 g/L的条件下,吸附24 h时的Hg~(2+)去除率达97.08%;污泥基生物炭对Hg~(2+)的吸附过程符合Langmuir等温吸附模型,吸附行为符合Lagergren准二级动力学方程。

Preparation of sludge biochar and its adsorption to Hg2+

Sludge biochar was prepared from municipal sludge by low temperature pyrolysis with addition of potassium acetate,and was used for adsorption of Hg²⁺ from solution. The factors affecting Hg²⁺ adsorption were studied and the adsorption mechanism was discussed. The characterization results show that pyrolysis has a certain effect on sludge pore-forming,and potassium acetate has greater influence on formation of pore structure. The experimental results show thatUnder the conditions of adsorption temperature 25 ℃,solution pH 6,initial Hg²⁺ mass concentration 15 mg/L and sludge biochar dosage 6 g/L,the Hg²⁺ removal rate reaches 97.08% after adsorption for 24 h;The adsorption process of Hg²⁺ on biochar is well fitted with Langmuir isothermal model,and the adsorption behavior follows the pseudo second-order kinetic equation.