胡敏素-锰氧化物复合材料对铅的吸附特征研究

Adsorption characteristics of Pb^(2+)by humin-MnO_(x)composite

以矿源煤基胡敏素(Humin,HM)为基体,用不同浓度KMnO_(4)溶液制备改性胡敏素材料胡敏素-锰氧化物复合材料(HMM),考察了HMM用量、初始pH对重金属的吸附效果影响;利用吸附动力学和吸附等温线以及扫描电镜(SEM)、红外光谱(FT-IR)等对其进行表征分析,探索了HMM对重金属的吸附机理。结果表明,HM表面负载MnO_(x)后增加了HM的表面吸附位点,随KMnO_(4)浓度的升高,HMM对Pb^(2+)吸附效果略有升高,吸附动力学遵循准二级动力学模型,化学吸附占主导作用;吸附等温线符合Langumir模型方程,0.05HMM对Pb^(2+)的最大吸附量Qm为397.911 mg/g,是HM的2.5倍;通过改性提高了HM对Pb^(2+)的吸附能力以及吸附的稳定性。

Humin-manganese oxide composites(HMM)are prepared through using mine-sourced coal-based humin as the matrix,which is in advance modified by different concentrations of KMnO_(4)solution.Its adsorption characteristics is tested through adsorbing Pb^(2+)in aqueous solution.The impacts of HMM dosage and the initial pH of solution on the adsorption of heavy metals by HMM are investigated.HMM is characterized by means of adsorption kinetics,adsorption isotherm,scanning electron microscopy(SEM)and infrared spectroscopy(FT-IR).The mechanism is also explored.Results show that the surface adsorption sites of humin increase after loading MnO_(x).The adsorption effect of HMM to Pb^(2+)increases slightly with the increasing KMnO_(4)concentration.The adsorption kinetics follows the quasi-second-order kinetic model,and chemisorption plays a dominant role.The adsorption isotherm accords with Langumir model equation.The maximum adsorption capacity of Pb^(2+)by 0.05HMM is 397.911 mg·g^(-1),which is 2.5 times that of pure humin.It is also verified that both the adsorption capacity and stability of humin for Pb^(2+)are improved by the modification.