改性膨润土对水中磷和藻类的同步去除

Simultaneous removal of phosphorus and algae in water by modified bentonite

为快速去除富营养化水体中的磷和藻类,制备了絮凝剂-镧复合改性膨润土(聚合氯化铝铁-镧复合改性膨润土(PAFC-La)、聚合硫酸铝-镧复合改性膨润土(PAS-La)、聚合硫酸铁-镧复合改性膨润土(PFS-La)、聚合氯化铝-镧复合改性膨润土(PAC-La)),对材料进行表征,通过吸附动力学和等温吸附模型比较4种复合改性膨润土的除磷性能,并探究投药量和pH对复合改性膨润土除磷除藻的影响。结果表明,4种材料吸附磷的过程均能由准二级动力学模型和Langmuir等温吸附模型描述。其中,PAC-La的磷吸附容量最大(44.677 mg/g);投药量为300 mg/L时,总磷(TP)去除率最高的是PAC-La(94.1%),叶绿素a(Chla)去除率最高的是PFS-La(78.2%);在pH为5~10时,PAC-La除磷除藻效果受pH影响最小。实验结果表明,采用絮凝剂-镧复合改性膨润土能够同步去除富营养化水体中的磷和藻类,尤其是采用PAC-La性能最优。

In order to quickly remove phosphorus and algae from eutrophic water,flocculant-lanthanum composite modified bentonite(composite bentonite modified by polyaluminium ferric chloride-lanthanum(PAFC-La),composite bentonite modified by polyaluminium sulfate-lanthanum(PAS-La),composite bentonite modified by polyferric sulfate-lanthanum(PFS-La),composite bentonite modified by polyaluminium chloride-lanthanum(PAC-La))were prepared.The materials were characterized and the phosphorus removal performance of four kinds of composite modified bentonite was compared by adsorption kinetics and isothermal adsorption model,and the effects of dosage and pH on phosphorus removal and algae removal of composite modified bentonite were explored.The results showed that the process of phosphorus adsorption by four materials could be described by quasi-second-order kinetic model and Langmuir isothermal adsorption model,among which PAC-La had the largest phosphorus adsorption capacity(44.677 mg/g).When the dosage was 300 mg/L,PAC-La had the highest removal rate of TP(94.1%),and PFS-LA had the highest removal rate of Chla(78.2%).In the range of pH 5-10,the effect of PAC-La on phosphorus and algae removal was least affected by pH.The experimental results showed that the bentonite modified by flocculant and lanthanum could simultaneously remove phosphorus and algae in eutrophic water samples,especially PAC-La had the best performance.