改性磁铁矿的制备及其对水中磷的吸附

Preparation of modified magnetite and its adsorption capacity for phosphorus in water

用硝酸钙和氯化镧对磁铁矿进行改性,考察不同初始浓度、pH、作用时间对含磷废水的吸附效果,进而分析其吸附等温线及动力学特性。结果表明:Langmuir等温吸附方程能很好地描述其等温吸附特性,未改性、硝酸钙改性、氯化镧改性的磁铁矿对磷的吸附饱和量分别为0.068、0.409、2.157 mg/g;未改性、硝酸钙改性、氯化镧改性的磁铁矿分别在pH为12、pH为8~12、pH为4~10时,对磷的吸附效果较好;氯化镧改性磁铁矿对磷的去除率达95%以上且其吸附过程符合二级吸附动力学方程。

Magnetite has been m odified by calcium nitrate and lanthanum chloride.The effects of different initial concentration,pH,and reaction time on the adsorption of phosphorus-containing wastewater are investigated,and the characteristics of adsorption isotherm and kinetics analyzed.The results show that Langmuir isotherm adsorption equation can well describe the isothermal adsorption characteristics.The saturated adsorption capacities of unmodified magnetite,calcium nitrate modified magnetite and lanthanum chloride modified magnetite for phosphorus are 0.068,0.409,2.157 mg/g,respectively.When the pH of unmodified magnetite is 12,pH of calcium nitrate modified magnetite 8-12,and lanthanum chloride modified magnetite 4-10,the adsorption effects on phosphorus are better.The removing rate of phosphorus by lanthanum chloride modified magnetite is above 95% and the adsorption courses comply well with pseudo second-order adsorption kinetics equation.