污泥生物炭对重金属Cd2+的吸附效果及作用机理  

Adsorption Effect and Mechanism of Sludge Biochar on Heavy Metal Cd2+

作　　者：隽茂玲 吴敏 

机构地区：[1]同济大学环境科学与工程学院,长江水环境教育部重点实验室,上海 [2]同济大学环境科学与工程学院,污染控制与资源化研究国家重点实验室,上海

出　　处：《水污染及处理》2022年第2期65-74,共10页Water Pollution and Treatment

摘　　要：使用450℃下热解制得的污泥生物炭(SBC)对重金属"Cd"进行吸附实验,并结合各种表征方法,研究SBC对Cd2+的吸附效果及作用机理。在本研究中,在初始Cd2+浓度为20~250 mg/L,反应时间为0~1440 min,pH值(2~8)和生物炭投加量(0.2~0.8 g)下进行批次吸附实验。实验结果表明最佳投加量0.3 g,pH值对吸附效果有显著影响。拟二级动力学模型和Langmuir等温线比其他模型更符合实验数据,表明污泥生物炭的吸附主要是单层化学吸附。根据吸附动力学和等温线分析,结合SEM、BET和FTIR结果,得出污泥生物炭对Cd2+的吸附机制主要为静电吸引、阳离子-π、表面络合以及沉淀作用。本研究得出结论,即剩余污泥制得的生物炭,可以作为一种低成本的吸附剂,用于去除废水中的重金属Cd。The sludge biochar (SBC) produced by pyrolysis at 450˚C was used to adsorb heavy metal Cd. Com-bined with various characterization methods, the adsorption effect and mechanism of SBC on Cd2+ were studied. In this study, batch adsorption experiments were carried out at initial Cd2+ concen-tration of 20~250 mg/L, contact time of 0~1440 min, different pH values (2~8) and biochar dose (0.2~0.8 g). The experimental results show that the optimal dosage is 0.3 g, and the pH value has a significant effect on the adsorption effect. The pseudo second-order kinetic model and Langmuir isotherm are more consistent with the experimental data than other models, indicating that the adsorption of sludge biochar is mainly monolayer chemical adsorption. According to the adsorption kinetics and isotherm analysis, combined with SEM, BET and FTIR results, it is concluded that the adsorption mechanism of sludge biochar on Cd2+ is mainly electrostatic attraction, cation-π, surface complexation and precipitation. This study concluded that the biochar prepared from excess sludge can be used as a low-cost adsorbent to remove heavy metal Cd in wastewater.

关 键 词：污泥生物炭 吸附 Cd2+ 作用机制 

分 类 号：X703[环境科学与工程—环境工程]