锰氧化膜包覆沸石的制备及其处理含锰水特性研究

Preparation of Manganese Oxide Membrane Coated Zeolite and Characteristics of Treating Manganese Containing Water

净水厂广泛采用石英砂或锰砂滤池,但在接触氧化法除锰过程中存在滤料吸附性能差、“锰质活性滤膜”成熟期长等问题。针对这一现象,以沸石为基质材料,高锰酸钾和硫酸锰生成锰氧化物沉积在沸石表面,制备锰氧化膜包覆沸石(MOMCZ),MOMCZ结合了沸石的吸附性能和锰氧化物的催化氧化特性。采用SEM、EDS、XPS、XRD、BET、Zeta电位等分析表征方法研究MOMCZ的表面形态、化学组成等特性,通过响应曲面模型分析MOMCZ对锰离子的吸附性能。结果表明:MOMCZ表面的锰氧化膜呈现立体复杂的网状结构,Mn元素存在形式及摩尔分数分别为Mn(Ⅲ)51.28%,Mn(Ⅳ)48.72%,锰氧化膜主要成分为Na0.55Mn_(2)O_(4)(H_(2)O)1.5;MOMCZ比表面积为38.76 m^(2)/g,孔径分布集中在3~40 nm,等电点pH=2.36;MOMCZ吸附锰离子的四项影响因素关系顺序为:pH值>负荷>吸附时间>吸附温度;通过模型优化发现当负荷为0.8 mg/g、pH=8.5、吸附温度为23.40℃、吸附时间为6.58 min时,锰离子去除率达到最大值70.82%;试验模型预测值和实际数据值相对误差均小于2.5%。MOMCZ吸附锰离子响应曲面模型拟合程度高、预测准确,具有较高的可行性和参考价值。

Quartz or manganese sand filters are widely used in water purification plants,however,there are problems such as poor adsorption performance of filter materials and a long time of“start-up period”in the process of contact oxidation manganese removal.In view of this phenomenon,manganese oxide membrane coated zeolite(MOMCZ)was prepared by using zeolite as the matrix material,and potassium permanganate and manganese sulfate were used to generate manganese oxide and then deposit on the surface of zeolite.MOMCZ was combined with the adsorption properties of zeolite and the catalytic oxidation characteristics of manganese oxide.SEM,EDS,XPS,XRD,BET,and Zeta potential analyses were used to observe surface morphology and chemical composite of MOMCZ.The response surface model was used to analyze the effect of adsorption performance of MOMCZ on manganese ions.The results show that manganese oxide membrane on surface of MOMCZ exhibits a three-dimensional complex network structure.The existing forms and molar ratio of Mn element are 51.28% for Mn(Ⅲ)and 48.72% for Mn(Ⅳ).Na_(0.55)Mn_(2)O_(4)(H_(2)O)_(1.5) is the main component of manganese oxide membrane.The specific surface area of MOMCZ is 38.76 m^(2)/g,and the pore size distribution is concentrated in the range of 3~40 nm and the isoelectric point pH value is 2.36.The order of four influencing factors for adsorption of manganese ions by MOMCZ is pH value>load>adsorption time>adsorption temperature.Through model optimization,it is found that the maximum manganese ion removal rate reaches 70.82% at the load of 0.8 mg/g,pH=8.5,adsorption temperature of 23.40℃,and adsorption time of 6.58 min.The relative error between the predicted values of experimental model and the actual data values is less than 2.5%.The response surface model of MOMCZ adsorption manganese ion has a high degree of fitting and accurate prediction,and has high feasibility and reference value.