The long-term storage of phosphate tailings will occupy a large amount of land,pollute soil and groundwater,thus,it is crucial to achieve the harmless disposal of phosphate tailings.In this study,high-performance geop...The long-term storage of phosphate tailings will occupy a large amount of land,pollute soil and groundwater,thus,it is crucial to achieve the harmless disposal of phosphate tailings.In this study,high-performance geopolymers with compressive strength of 38.8 MPa were prepared by using phosphate tailings as the main raw material,fly ash as the active silicon-aluminum material,and water glass as the alkaline activator.The solid content of phosphate tailings and fly ash was 60%and 40%,respectively,and the water-cement ratio was 0.22.The results of XRD,FTIR,SEM-EDS and XPS show that the reactivity of phosphate tailings with alkaline activator is weak,and the silicon-aluminum material can react with alkaline activator to form zeolite and gel,and encapsulate/cover the phosphate tailings to form a dense phosphate tailings-based geopolymer.During the formation of geopolymers,part of the aluminum-oxygen tetrahedron replaced the silicon-oxygen tetrahedron,causing the polycondensation reaction between geopolymers and increasing the strength of geopolymers.The leaching toxicity test results show that the geopolymer has a good solid sealing effect on heavy metal ions.The preparation of geopolymer from phosphate tailings is an important way to alleviate the storage pressure and realize the resource utilization of phosphate tailings.展开更多
以真空冷冻干燥预处理后的污水污泥(VFD-SS)为生物质前体,通过一步水热炭化制备了镧改性磁性污泥生物炭(VFD-MSBC)用于吸附水中磷酸盐,实现污泥的处理及资源化利用。Box-Behnken响应面实验分析了不同因素及其交互作用对磷吸附量的影响,...以真空冷冻干燥预处理后的污水污泥(VFD-SS)为生物质前体,通过一步水热炭化制备了镧改性磁性污泥生物炭(VFD-MSBC)用于吸附水中磷酸盐,实现污泥的处理及资源化利用。Box-Behnken响应面实验分析了不同因素及其交互作用对磷吸附量的影响,得到最佳制备工艺条件为:1.05 g VFD-SS、0.069 g C_(6)H_(8)O_(6)、1.05 g FeCl_(3)·6H_(2)O、1.906 g LaCl_(3)·6H_(2)O;水热反应条件为:168℃,4.6 h。在此条件下制备的VFD-MSBC磷吸附量为39.4454 mg/g,与模型预测值的相对偏差<5%。生物炭的表征分析结果证明了La(OH)_(3)的成功负载,同时发现真空冷冻干燥预处理改变了污泥生物质与生物炭的物理化学性质,使VFD-MSBC具有更高的磷吸附性能。展开更多
基金Project(202202AG050010)supported by the Yunnan Major Scientific and Technological Projects,ChinaProject(202103AA080007)supported by the Key R&D Project of Science and Technology Department of Yunnan Province,ChinaProject(NECP2023-06)supported by the Open Project Fund of National Engineering and Technology Research Center for Development&Utilization of Phosphorous Resources,China。
文摘The long-term storage of phosphate tailings will occupy a large amount of land,pollute soil and groundwater,thus,it is crucial to achieve the harmless disposal of phosphate tailings.In this study,high-performance geopolymers with compressive strength of 38.8 MPa were prepared by using phosphate tailings as the main raw material,fly ash as the active silicon-aluminum material,and water glass as the alkaline activator.The solid content of phosphate tailings and fly ash was 60%and 40%,respectively,and the water-cement ratio was 0.22.The results of XRD,FTIR,SEM-EDS and XPS show that the reactivity of phosphate tailings with alkaline activator is weak,and the silicon-aluminum material can react with alkaline activator to form zeolite and gel,and encapsulate/cover the phosphate tailings to form a dense phosphate tailings-based geopolymer.During the formation of geopolymers,part of the aluminum-oxygen tetrahedron replaced the silicon-oxygen tetrahedron,causing the polycondensation reaction between geopolymers and increasing the strength of geopolymers.The leaching toxicity test results show that the geopolymer has a good solid sealing effect on heavy metal ions.The preparation of geopolymer from phosphate tailings is an important way to alleviate the storage pressure and realize the resource utilization of phosphate tailings.
文摘以真空冷冻干燥预处理后的污水污泥(VFD-SS)为生物质前体,通过一步水热炭化制备了镧改性磁性污泥生物炭(VFD-MSBC)用于吸附水中磷酸盐,实现污泥的处理及资源化利用。Box-Behnken响应面实验分析了不同因素及其交互作用对磷吸附量的影响,得到最佳制备工艺条件为:1.05 g VFD-SS、0.069 g C_(6)H_(8)O_(6)、1.05 g FeCl_(3)·6H_(2)O、1.906 g LaCl_(3)·6H_(2)O;水热反应条件为:168℃,4.6 h。在此条件下制备的VFD-MSBC磷吸附量为39.4454 mg/g,与模型预测值的相对偏差<5%。生物炭的表征分析结果证明了La(OH)_(3)的成功负载,同时发现真空冷冻干燥预处理改变了污泥生物质与生物炭的物理化学性质,使VFD-MSBC具有更高的磷吸附性能。
