镧铝复合改性膨润土的制备及其对磷酸盐吸附性能的研究

Preparation and Phosphate Adsorption Performance of Lanthanum Aluminum Composite Modified Bentonite

采用氯化镧和聚合氯化铝对多种载体进行改性,并对不同的镧铝负载量进行了探究,成功制备了一种对磷酸盐具有高亲和力的镧铝改性膨润土,FTIR和XRD分析证实镧铝元素成功负载到膨润土结构中,进一步通过吸附实验,探究了该改性膨润土的吸附特性及影响因素。结果表明,经过镧铝复合溶液改性后的膨润土对磷酸盐的特异性吸附能力显著增强,且镧铝配比为1∶4时该吸附剂的吸附速率最快,且饱和吸附量达10.34 mg/g,吸附曲线拟合结果符合Langmuir等温方程,表明吸附行为符合单分子层吸附模型。该材料与商业磷酸盐吸附剂Phoslock有着相似的吸附性能,但具有制法简单、成本低廉、环境友好等优势。影响因素研究结果显示,该吸附材料可适应很宽的水体pH范围,且NO^(-)_(3)、SO^(2-)_(4)和Cl^(-)等共存离子对吸附量影响较小,大大增加了该材料在水体除磷中的应用潜力。

Lanthanum chloride and polyaluminium chloride were used to modify a variety of carriers,and different loading loads of lanthanum and aluminum were explored.Finally,lanthanum aluminum modified bentonite with high affinity for phosphate was successfully prepared,in which lanthanum and aluminum were successfully loaded into the bentonite structure confirmed by FTIR and XRD analysis.The adsorption characteristics and influencing factors of the modified bentonite were further investigated.The results showed that the specific adsorption capacity of bentonite modified by lanthanum aluminum composite solution was significantly enhanced.The adsorption rate was the fastest when the ratio of lanthanum to aluminum was 1∶4,and the saturated adsorption capacity reached 10.34 mg/g.The adsorption curve fitted with the Langmuir isothermal equation,indicating that the adsorption behavior conforms to the monolayer adsorption model.The modified bentonite has similar adsorption properties to the commercial phosphate adsorbent Phoslock,but has the advantages of simple preparation,low cost and environmental friendliness.The investigation of influencing factors showed that the adsorbent could adapt to a wide pH range,and the coexisting ions including NO^(-)_(3)、SO^(2-)_(4)and Cl^(-)had little influence on the adsorption capacity,which greatly increased the application potential of the adsorbent in phosphorus removal.