不同粘土矿物对磷污染水体的吸附净化性能比较

Phosphate adsorption capacities of different clay minerals in phosphate-contaminated water

比较了凹凸棒石粘土、高岭土、膨润土和蛭石等4种粘土矿物共8个样品对不同程度磷污染水体的吸附净化能力。结果发现,4种供试粘土矿物对水体磷均有一定的吸附净化潜力,但针对不同程度磷污染水体存在一定差异,且同一种粘土矿物的吸附净化能力也会因矿物组成差异而不同;针对模拟Ⅴ类水(ρ(P)=0.4mg·L-1),高岭土的吸附净化能力最强,其次凹凸棒石粘土和膨润土的吸附净化能力与活性炭接近,而蛭石的吸附净化能力较差;针对模拟劣Ⅴ类水(ρ(P)=1.0mg·L-1),膨润土的吸附净化能力最强,蛭石次之,高岭土因矿物组成不同而有很大差异,凹凸棒石粘土的吸附净化能力与活性炭较为接近。结果表明,凹凸棒石粘土和膨润土针对不同程度磷污染水体的应用范围较宽,高岭土最适用于Ⅴ类磷污染水体,而蛭石可应用于劣Ⅴ类磷污染水体。

Phosphate adsorption capacities of four different clay minerals, including eight samples, in Phosphate-contaminated waters different in phosphate concentration were investigated. Results showed that the phosphate adsorption capacities of four clay minerals were different in waters different in phosphate concentrations, and also did the same clay with different mineral constituents. In water of Grade V （P 0.4 mg.L^-1）, kaolinite had the highest adsorption capacity, followed by attapulgite and bentonite, whose removal efficiencies were close to that of activated carbon, then the vermiculite. While in water of Grade V-minus （P 1.0 mg·L^1）, bentontie had the highest removal rate, followed by vermiculite, then the attapulgite, whose removal efficiencies was also approached to that of activated carbon, while different kaolinite samples had great different phosphate removal efficiencies, due to their discrepant composition. The results depicted above reveal that attapulgite and bentonite had a wider application in phosphatecontaminated waters and should be energetically explored, and kaolinite and vermiculite could be used as natural adsorbents in water of Grade V （P 0.4 mg·L^-1） and in water of Grade V-minus （P 1.0 mg·L^-1）, respectively.