低品位锰矿吸附砷(Ⅲ)的化学机理研究

Chemical adsorption mechanism of low-grade manganese ore on arsenic

为了研究天然锰矿的化学吸附性能,通过能谱扫描、电镜扫描、X射线衍射、快速电位滴定法和红外官能团检测分析锰矿的基本性质,同时由批次实验探究了吸附时间、砷初始浓度和离子强度对锰矿吸附砷的效率的影响,并分析锰矿吸附砷过程中的吸附动力学、吸附等温线类型、主要官能团和吸附类型。结果显示,锰矿对砷的吸附符合二级动力学吸附模型和Freundlich吸附等温线模型,Mn-OH、α-Fe OOH和α-Fe2O3为吸附的主要作用基团,吸附类型属于以形成内层配位络合物为主的专性吸附。

To study the chemical adsorption properties of natural manganic ore, the methods of spec-troscopy scanning, scanning electronic microscopy, X-ray diffraction, rapid point titration methods and fourier transform infrared detection were employed to analyze the basic properties of manganic ore. The effects of adsorption time, initial concentration and ionic strength on arsenic adsorption rate of manganic ore were investigated. Based on the properties of the ores and the batch experiments, the adsorption kinetics, adsorption isotherm types, major functional groups and adsorption type were analyzed. The results showed that, adsorption process fitted the Freundlich isotherm model and the pseudo-second order kinetic model;Mn-OH,α-FeOOH andα-Fe2 O3 were the major groups of ad-sorption. Throughout the adsorption process, arsenic anions formed inner-sphere surface complexes, and the type of adsorption was specific adsorption.