改性高岭土对水体中氮磷去除效果的研究

Removal Effects of NH_4^+-N and P from Water by Modified Kaolinite

利用恒温振荡试验,研究了酸、碱、盐改性高岭土对水体中氮、磷去除效果的影响。结果表明,各处理高岭土对水体中氮、磷的吸附速率均较快,在2 h内均能达到吸附平衡。由Freundlich等温吸附方程模拟得出各处理高岭土对氮的吸附能力大小为Al处理>Ca处理>碱处理>Mg处理>原土>酸处理;对磷的则为Al处理>Mg处理>Ca处理>酸处理>原土>碱处理。由Langmuir等温吸附曲线方程得出各处理高岭土对氮的理论饱和吸附量顺序为Mg处理>Ca处理>碱处理>Al处理>原土>酸处理;对磷的则为Al处理>Ca处理>Mg处理>酸处理>原土>碱处理。各处理高岭土去除氮的适宜pH值为5.5~8.5,去除磷的适宜pH值为4~8.5。

High concentration of N and P in water cause eutrophication, and it is necessary to develop effective, environment-friendly and cheap materials to remove them. In laboratory,modification treatment of kaolinite was conducted by means of addition of Al2（SO4）3, CaCl2, MgCl2 as activator at high temperature and immersion in acid and alkal. Then, constant temperature rocking-experiments were conducted to study the effects of NH4＋-N and P removal from water. The results showed that the adsorption rates of NH;-N and P on kaolinite and modified kaolinites were higher, and the equilibrium states reached in 2 h. The adsorption capacity of NH;-N for all treatments simulated by Fre- undlieh equation were：Al-modification〉 Ca-modification 〉alkali-modification〉Mg-modification 〉kaolinite〉acid-modification, and that of phosphate were：Al-modification〉Mg-modification〉Ca-modification 〉acid-modification 〉 kaolinite 〉alkali-modification. The adsorption to P was stronger than to NH2-N. The order of theoretical saturated adsorption amount of NH4＋-N for all treatments simulated by Langmuir equation were Mg-modification〉Ca-modification〉 alkali-modification 〉Al-modification〉 kaolinite acid-modification, and that of phosphate were M-modification〉 Ca-modification 〉 Mg-modification〉acid-modification〉kaolinite 〉alkali-modification.Adsorption buffer capacity of Mg-modification kaolinite to NHZ-N was strongest,and that to P was Al-modification kaolinite.The suitable pH value of all treatments for NH;-N removal was 5.5~8.5 and for P was 4-8.5.