锰氧化物制备及其对锰和氨氮的去除研究

Preparation of Manganese Oxide and Its Removal Performance of Manganese and Ammonium

为制备具有优良吸附性能的材料,采用高锰酸钾氧化(分别在酸性条件和中性条件下进行)和空气自然氧化水中2价锰,制备了3种锰氧化物(ORIG-MnO_(x)、Na_(2)CO_(3)-MnO_(x)、O2-MnO_(x)),对其结构进行了表征,并探究了对水中NH_(4)^(+)-N和Mn^(2+)污染的去除特性及影响因素。结果表明,所制备的ORIG-MnO_(x)与Na_(2)CO_(3)-MnO_(x)为结晶度较低的ε-MnO_(2),但二者形貌和精细结构存在明显差异,O_(2)-MnO_(x)为结晶度较高的黑锰矿(Mn_(3)O_(4));ORIG-MnO_(x)、Na_(2)CO_(3)-MnO_(x)具有比O_(2)-MnO_(x)更好的除Mn^(2+)、除NH_(4)^(+)-N性能,且Na_(2)CO_(3)-MnO_(x)吸附性能最佳,其NH_(4)^(+)-N和Mn^(2+)去除过程符合Langmuir吸附等温线模型和准2级反应动力学模型。可为以锰氧化物为基础的NH_(4)^(+)-N和锰的去除工艺提供理论和技术支撑。

In order to prepare materials with excellent adsorption performance,potassium permanganate(performed under acidic and neutral conditions)and air were used to oxidize Mn^(2+)in water and three species of manganese oxides(ORIG-MnO_(x),Na_(2)CO_(3)-MnO_(x),O_(2)-MnO_(x))were prepared respectively.Their structures were characterized and the performance and influence factor of the removal of NH_(4)^(+)-N and Mn^(2+)in water were investigated.The results showed that,although the prepared ORIG-MnO_(x) and Na_(2)CO_(3)-MnO_(x) were ε-MnO_(2) with lower crystallinity,their morphology and fine structure were significantly different,and O_(2)-MnO_(x) was hausmannite(Mn_(3)O_(4))with higher crystallinity.ORIG-MnO_(x)and Na_(2)CO_(3)-MnO_(x) had better Mn^(2+)and NH_(4)^(+)-N removal performance than O_(2)-MnO_(x),and the adsorption performance of Na_(2)CO_(3)-MnO_(x)was the best.The removal process of Mn^(2+)and NH_(4)^(+)-N could be fitted with Langmuir adsorption isotherm model and quasi-second-order reaction kinetics model.This study can provide theoretical and technical support for the removal of NH_(4)^(+)-N and manganese based on manganese oxide.