天然锰矿对水体中磷的去除研究

研究了天然锰矿对水体中磷的去除效果,考察了温度、光照、锰矿用量、溶液pH及共存离子对除磷效果的影响。结果表明,pH对磷的吸附影响很大。离子影响中,Ca2+、Mg2+、CO32-、HCO3-、SiO32-和SO24-的影响不大,而AsO43-和AsO3-却能明显抑制锰矿对磷的吸附。Freundlich等温吸附模型(r2=0.984 4)能很好的描述磷的吸附。动力学数据符合二级动力学模型(r2=0.999 9),最大吸附量为30.40μg/g。FTIR和SEM结果显示磷主要是通过与锰矿表面的羟基发生置换或生成内层络合物而被吸附。天然锰矿,具有较大的比表面积,强选择性,是一种很有前景的去除天然水体中磷的吸附剂。

Adsorption of Phosphate onto Natural Manganese Ore

Adsorption of phosphate from aqueous solution onto natural manganese ore was investigated.The effects of different experimental parameters,namely temperature,light,natural manganese ore amount,solution pH,and interfering ion dosage on the phosphate adsorption were investigated.It was found that the phosphate adsorption was highly pH dependent.Ca2+,Mg2+,CO2-3,HCO-3,SiO2-3 and SO2-4 had no significant effect on phosphate removal.However,the percentage of phosphate removal obviously decreased with increasing concentration of AsO3-4 and AsO3-3.The adsorption isotherm was fitted well with Freundlich isotherm model(r2=0.984 4).The kinetic data correlated well with the second order kinetic model(r2=0.999 9),and the maximal adsorption capacity was 30.40 μg/g.The FTIR spectrum and SEM image show that the phosphate removal was mainly achieved through the replacement of surface hydroxyl groups by the phosphate species and the formation of inner-sphere surface complexes at the water/oxide interface.