Phosphorus adsorption capacities of 8 types of natural clay laterites and treated (roasted or spiked with natural minerals) clay laterites in phosphorus-polluted water were investigated in a simulation experiment and mechanisms of the laterites adsorbing phosphorus explored through isothermal adsorption.Results show that all the 8 types of natural clay laterites were more or less able to adsorb phosphorus in water,but they varied in performance in waters different in pollution degree.The clay laterite from Jiangxi province was the highest in P removal efficiency in wastewaters of Grade V or Grade V on the lower side.The Freundlich equation fitted well with phosphate adsorption isothermal curves of the natural clay laterites in terms of R2 value,which indicates that the adsorption was in the form of inhomogeneous multi-molecular-layer adsorption.In wastewater with the initial phosphorus concentration reaching 200 mg · L-1,the natural lay laterites might adsorb as much as 2.38 mg · g-1 phosphorus.Roasting or baking significantly enhanced the soils' phosphate adsorption capacity.Spiking natural minerals did not have much effect on phosphorus adsorption capacity of the soils,but could effectively neutralize acidity of the effluents.All the findings demonstrate that clay laterites can be used potentially as adsorbent to purify phosphorus-polluted wastewater,and different processing methods should be adopted to improve P adsorption and wastewater purification efficiency of the materials.%通过模拟实验方法,比较了8种天然黏粒红土和焙烧、天然矿物复配等处理的黏粒红土对磷污染水体的吸附净化能力,通过等温吸附探讨了黏粒红土的磷吸附机制.结果发现,8种供试天然黏粒红土对水体磷均具有一定的吸附净化能力,但对不同程度磷污染水体净化能力存在差异;针对Ⅴ类水和劣Ⅴ类水,均以江西黏粒红土表现出最高的磷吸附净化能力;天然黏粒红土的磷吸附等温曲线与Freundlich方程拟合显著,说明黏粒红土对磷的吸附属于不均匀介质的多分子层吸附;在磷初始浓度为200 mg·L-1时,天然黏粒红土对磷的吸附容量最高可达2.38 mg·g-1.此外,焙烧能显著增强黏粒红土对磷污染水体的吸附能力,黏粒红土可以作为磷污染水体的潜在吸附材料,针对实际水体可选用不同处理方法来提高其对污水磷的吸附净化效率.
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