二元金属复合氧化物组份间相互作用对砷吸附性能与机制的影响

Exposure to arsenic can cause huge adverse effects on human health.Thus, efficient and economical removal of arsenic from drinking water has always been attracting attention at home and abroad. Adsorption is believed to be one of the most simply-operated, economical and feasible alternatives for arsenic removal.Recentally,the development of novel binary metal oxide adsorbents has gained increasing concerns.Interaction between component oxides can influence the crystallinity, morphology, surface element distribution and surface charge of the formed metal composite oxides; and then affect their arsenic adsorption properties and mechanisms.Therefore,it is very essential to comprhensively understand the effect of component oxides interaction on arsenic adsorption properties and mechanisms, since this will provide meaningful insight and inspiration to the development of novel metal oxide adsorbents. However, up to now, no systematical and thorough research has been reported at home and abroad. Threrfore, four typical bianry metal oxides (Fe-Cu, Fe-Al, Fe-Ti, and Fe-Mn binary oxides) are chosen as model objecitves in this project, which will be synthesized through differernt methods including physical mixing, co-precipitation, sol-gel process, and hydrothermal reaciton. The difference in the interaciton between component oxides of the synthesized binary oxides will be determined by XRD and Mossbauer spectroscopy.The relationship between the component oxides interaction and arsenic adsorption properties and mechanisms will be sysmetacilly investigated using batch adsorption experiemnts combined with various characterization techniques such as titration, BET measurement, FTIR, TEM, and XAS, to elucidate how the interaciton between componet oxides influences the arsenic adsorption performance and mechanim of binary metal oxides.

砷对人体健康危害极大，如何高效、经济地去除饮用水中砷污染物始终是国内外研究的重点。吸附是最可行的一种除砷方法，新型金属复合氧化物吸附剂的开发，是该研究领域的前沿与热点。金属复合氧化物组份间相互作用可影响其晶型、形貌结构、表面元素分布及表面电荷等，进而影响其砷吸附性能与机制。深入认识这种相互作用对砷吸附性能与机制的影响，对新型金属复合氧化物除砷吸附剂的开发有重要指导作用。而到目前为止，国内外相关研究很少，且不够深入。基于此，本项目以具广泛代表性的铁铜、铁铝、铁钛及铁锰四个二元金属复合氧化物体系为研究对象，分别采用机械混合、共沉淀、溶胶凝胶及水热法，合成系列组份间相互作用不同的金属复合氧化物，通过批式吸附实验，结合表面滴定、红外、比表面仪、同步辐射等技术，系统、深入地研究复合氧化物组份间相互作用与砷吸附特性及机制间的内在关系，揭示组份间相互作用对金属复合氧化物砷吸附特性及机制的影响规律。

砷对人体健康危害极大，如何高效、经济地去除饮用水中砷污染物始终是国内外研究的重点。吸附是最可行的一种除砷方法，新型金属复合氧化物吸附剂的开发，是该研究领域的前沿与热点。金属复合氧化物组份间相互作用可影响其晶型、形貌结构、表面元素分布及表面羟基等，进而影响其砷吸附性能与机制。本项目分别采用机械混合、共沉淀、水热法，合成了系列组份间相互作用不同的铁铜、铁钛、铁锰等二元金属复合氧化物。通过多种技术手段，对制备的二元金属复合金属氧化物的形貌结构、晶型等进行了系统表征；研究了复合氧化物组份间相互作用对砷吸附特性及机制间的影响；分析了组份间相互作用与二元金属复合氧化物砷吸附性能之间的关系。研究结果表明：合成的二元金属复合金属氧化物由细小纳米颗粒团聚而成；制备方法可影响二元金属复合氧化物组份间相互作用强弱，而这种相互作用决定了复合氧化物的表面形貌、晶型及比表面积、表面金属羟基含量等表面性质，作用越弱，复合氧化物的晶型越差，比表面积和单位质量表面羟基含量越大，相反，作用越强，复合氧化物的晶型越好，比表面积和单位质量表面羟基含量越低；二元金属复合氧化物的砷吸附效能与其表面羟基含量呈良好的正相关性,表面羟基含量越多，砷吸附容量越大；二元金属复合氧化物组份间相互作用不影响砷吸附机制。总之，二元金属复合氧化物组份间相互作用决定其表面性质，进而影响其砷吸附效能。上述研究结果有助于深入认识其他二元金属复合氧化物体系相互作用对砷吸附效能的影响，并对新型、高效二元或多元金属复合氧化物吸附剂的开发有重要的理论指导作用。