摘要
采用简单共沉淀法制得椰壳生物炭/Ca/La层状双金属氢氧化物(Ca/La-LDH)复合新型吸附剂(CLYK).通过SEM-EDS、BET、XRD、FTIR和XPS等对材料进行表征,研究了金属负载量、吸附剂投加量、初始pH值、共存离子及有机物对吸附磷酸盐的影响,以及吸附动力学、等温线、热力学和位点能量分布的特征.结果表明:CLYK对磷酸盐有良好的吸附性能,在金属负载量为70%,投加量为1g/L,pH值为5时,最大吸附容量为214.742mg/g.CLYK的pH值适用范围广,在3~10时具有较大的吸附容量,共存离子及有机物存在下表现出对磷酸盐的高选择性吸附,吸附解吸循环试验证明了CLYK具有较好的可重复利用性.CLYK吸附磷酸盐过程符合Freundlich和准二级动力学模型,主要为多层化学吸附,热力学分析结果表明吸附为自发吸热反应.吸附机制包括化学沉淀、通过配体交换形成内球络合和静电吸引.
A novel composite adsorbent(CLYK)of coconut shell biochar/Ca/La layered double hydroxide(Ca/La-LDH)was synthesized via a simple co-precipitation method.The materials were characterized by SEM-EDS,BET,XRD,FTIR and XPS,and the effects of metal loading,adsorbent dosage,initial pH value,co-existing ions and organic matter on phosphate adsorption,as well as the characteristics of adsorption kinetics,isotherms,thermodynamics and site energy distribution were investigated.The results showed that CLYK had good adsorption performance for phosphate,with a maximum adsorption capacity of 214.742mg/g at metal loading of 70%,dosage of 1g/L and pH value of 5.Moreover,CLYK displayed a wide range of pH adaptability with significant adsorption capacity observed between pH 3~10.It also demonstrated high selectivity for phosphate in the presence of coexisting ions and organic matter,and the adsorption-desorption cycle test proved that CLYK has a good reusability.The adsorption process of phosphate by CLYK conformed to the Freundlich and quasi-second-order kinetic model,which was multilayer chemisorption,The thermodynamic analysis indicated that the adsorption was a spontaneous endothermic reaction.Chemical precipitation,formation of inner-sphere complexes via ligand exchange,and electrostatic attraction were mechanisms of phosphorus adsorption.
作者
高敬毅
崔佳丽
杨栋
GAO Jing-yi;CUI Jia-li;YANG Dong(College of Environmental Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi Engineering Center for Sludge Disposal and Resource,Taiyuan 030024,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2024年第10期5584-5595,共12页
China Environmental Science
基金
山西省自然科学基金资助项目(202103021224083)。
