锰氧化物-阳离子交换树脂复合材料的制备及其对水中重金属的吸附性能

Preparation of manganese oxide-cation exchange resin hybrid material and its adsorption property for heavy metals in aqueous solution

采用原位沉淀-空气氧化法将锰氧化物负载于大孔强酸性阳离子交换树脂D001上,制备出一种新型锰氧化物-阳离子交换树脂复合材料Mn-D001,并对该材料吸附水中Pb2+、Cd2+、Cu2+的性能进行了深入研究.TEM、XRD以及XPS的分析结果表明,负载的锰氧化物以MnO2的形态存在.基于单一金属离子静态吸附的一元体系实验表明,Mn-D001比D001对Pb2+、Cd2+、Cu2+具有更高的吸附选择性,在高浓度竞争离子Ca2+、Mg2+、Na+共存的情况下,仍能保持较高的重金属去除率;Mn-D001对Pb2+、Cd2+、Cu2+的吸附行为符合准一级动力学模型(R2>0.99)和Langmuir吸附等温线模型(R2>0.99).在温度为303 K时,Mn-D001对3种重金属的饱和吸附容量可分别达到476.19 mg.g-1、243.90 mg.g-1及196.08 mg.g-1,优于原有树脂D001.基于复合重金属离子竞争吸附的二元、三元体系的实验表明,Mn-D001对3种重金属的吸附能力顺序为Pb2+>Cu2+>Cd2+,吸附能力由原有树脂D001以及负载的锰氧化物的性质共同决定.

A simple method of in-suit deposition and air oxidation was used to synthesize a new manganese oxide-cation exchange resin hybrid material（Mn-D001） by coating manganese oxide onto a macroporous strong acid cation exchange resin（D001）.The adsorption property for Pb2＋,Cd2＋and Cu2＋ was tested deeply in single,binary and ternary solution systems,respectively.The results of TEM,XRD and XPS indicated that the form of manganese oxide loaded on the resin was MnO2.In single solution,Mn-D001 had higher adsorption selectivity to Pb2＋,Cd2＋and Cu2＋ than D001,which can be proven by the higher removal rate of heavy metals on Mn-D001 than that of D001 when Ca2＋,Mg2＋ and Na＋ ions coexisted in high concentration.The adsorption of Pb2＋,Cd2＋ and Cu2＋ on Mn-D001 was well described by pseudo-first-order kinetic model and Langmuir isotherm model（R20.99）.And the maximum adsorption capacity of Mn-D001 toward Pb2＋,Cd2＋and Cu2＋ were up to 476.19 mg · g-1,243.90 mg · g-1 and 196.08 mg · g-1 respectively at 303 K,which is superior to D001.The order of competitive adsorption capacity of three heavy metals onto Mn-D001 was Pb2＋Cu2＋Cd2＋,which was deduced through the batch experiments in binary and ternary solution system.The order was determined by the characteristics of both host resin D001 and loaded manganese oxide.