镧、锆改性油菜杆和菱角壳去除养猪废水中的磷

磷是引起地表水富营养化的重要因素之一，选择高效低成本的吸附材料是去除废水中磷的关键所在。基于此，采用共沉淀法制得镧、锆改性的油菜秆(La-BC、Zr-BC)和菱角壳(La-TN、Zr-TN)，探究了其对模拟废水中磷的吸附去除；分别考察了在改性材料不同投加量、溶液pH、磷的初始浓度、反应时间等条件下对磷吸附特征的影响。FT-IR和SEM-EDS表征结果表明，镧和锆均已成功负载于油菜秆和菱角壳的表面上。La-TN、La-BC、Zr-TN和Zr-BC对磷的吸附量随改性材料投加量的增加呈指数下降，最大吸附量分别为12.49、11.41、6.85、6.83 mg$ \cdot {{\rm{g}}}^{-1}$。随pH的上升，镧改性材料对磷的吸附量呈先上升后下降的趋势，而锆改性材料呈幂函数式下降。4种改性材料的吸附动力学使用叶诺维奇模型描述更为合适，且吸附等温线使用Freundlich模型拟合更佳。La-BC、Zr-BC、La-TN、Zr-TN在养猪废水中吸附量分别为14.82、10.36、15.41和8.91 ${\rm{m}}{\rm{g}} \cdot {{\rm{g}}}^{-1}$，较改性前分别提升了34、20、53、37倍，这表明4种改性材料可作为养猪废水中除磷的潜在材料。以上研究结果可为废水中磷的去除及农业废弃物的资源化利用提供一定的参考。

Lanthanum and zirconium modified rape stalk and water chestnut shell removing phosphorus from swine wastewater

Phosphorus is one of the important factors causing eutrophication of surface water, and the key to remove phosphorus from wastewater is to select high-efficiency and low-cost adsorption materials. Based on this, lanthanum and zirconium modified rape stalks (La-BC, Zr-BC) and water chestnut shells (La-TN, Zr-TN) were prepared by coprecipitation method, and their adsorption and removal of phosphorus in the simulated wastewater were investigated. The effects of different dosages of modified materials, pH of solution, initial concentration of phosphorus and reaction time on phosphorus adsorption characteristics were investigated, respectively. FT-IR and SEM-EDS characterization results showed that lanthanum and zirconium were successfully loaded on the surfaces of rape stalks and water chestnut shells. The adsorption capacity of La-TN, La-BC, Zr-TN and Zr-BC to phosphorus decreased exponentially with the increase of the dosage of modified materials, and their maximum adsorption capacities were 12.49, 11.41, 6.85 and 6.83 ${\rm{m}}{\rm{g}} \cdot {{\rm{g}}}^{-1}$, respectively. With the increase of pH, the adsorption capacity of lanthanum modified materials to phosphorus increased first and then decreased, while the adsorption capacity of zirconium modified materials decreased in power function. It was more suitable to describe the adsorption kinetics of the four modified materials using the Elovich model, and the Freundlich model was better to fit the adsorption isotherms. The adsorption capacities of La-BC, Zr-BC, La-TN, Zr-TN in swine wastewater were 14.82, 10.36, 15.41 and 8.91 ${\rm{m}}{\rm{g}} \cdot {{\rm{g}}}^{-1}$, respectively, which increased by 34, 20, 53 and 37 times of the pristine materials, indicating that the four modified materials had potential for phosphorus removal in swine wastewater. The results of this study can provide some references for the removal of phosphorus from wastewater and the recycling of agricultural wastes.