不同改性黏土矿物吸附净化磷污染水体的性能比较

比较了酸、热及其复合改性对凹凸棒石黏土、膨润土和高岭土等3种黏土矿物吸附净化不同程度磷污染水体能力的影响。结果发现,2%浓度酸处理、300℃热活化及酸热复合改性均可以显著提高凹凸棒石黏土的磷吸附净化能力,且以复合改性效果最好,Ⅴ类和劣Ⅴ类水的磷去除率均比原土提高30%以上;酸、热改性均能显著提高膨润土的磷吸附净化能力,但综合不同程度磷污染水体来看,热活化略优于酸改性,但酸热复合改性没有呈现更佳的效果;热改性显著提高高岭土的磷吸附净化能力,而酸改性却不同程度地降低了高岭土的磷吸附净化能力,酸热复合改性的效果亦不如热单独改性。结果表明,在针对不同程度磷污染水体时需根据黏土矿物特性选用酸处理、热活化或酸热复合改性方法来提高污水的吸附净化效率。

Phosphate Adsorption Capabilities of Modified Clay Minerals in Phosphate-Contaminated Water

Phosphate adsorption capabilities of modified clay minerals in water with different phosphate concentrations were investigated.The modified clays were prepared by being activated with hydrochloric acid,thermal and acid-thermal treatments.The results showed that the acid-thermal treated attapulgite had the highest adsorption capabilities,whose removal efficiencies increased by above 30% in water quality of order Ⅴ and less than order Ⅴ,followed by thermal activated attapulgite,then attapulgite modified with 2% hydrochloric acid.All modified bentonite samples had higher adsorption capabilities than natural bentonite.As a whole,thermal treatment was slightly superior to acid activation,but acid-thermal treatment had no better effect on phosphate adsorption capabilities than thermal treatment and acid activation.Thermal treatments evidently improved the adsorption capabilities of kaolinite,also did the acid-thermal treatments,with contrast to acid treatments,which decreased the adsorption capabilities of kaolinite.The results revealed that different modified methods should be choosed,in view of the characteristics of clay minerals,to improve removal efficiencies in water with different phosphate concentrations.