摘要
以除铁除锰生物滤池反冲洗泥为主要原料制备除砷颗粒吸附剂(granular adsorbents for arsenic removal,GA),使用SEM、XRD与BET等技术对其进行表征,并考察了GA对As(Ⅴ)的吸附机制和性能.结果表明,GA表面粗糙且孔隙发达;XRD图谱中出现石英晶体和少量赤铁矿晶体衍射峰,内部结晶度差;比表面积为43.8 m^2·g^(-1),存在大量介孔.吸附动力学过程符合准二级动力学模型.Freundlich等温方程更符合其吸附行为(R2=0.994).最大吸附容量为5.05 mg·g^(-1).进一步分析表明,在pH为1.1~9.5的范围内,GA对As(Ⅴ)具有较好的吸附效果.H_2PO_4^-与SiO_3^(2-)能显著抑制As(Ⅴ)的吸附,而HCO_3^-、SO_4^(2-)对吸附效果影响相对较小.GA的可再生性好,3次再生后吸附量相当于初始吸附量的82%.
Granular adsorbents for arsenic removal（GA） made from the backwashing residuals from iron and manganese removal biofilters for groundwater were characterized and examined as an arsenate sorbent.The GA were characterized by SEM-EDS microscopy,X-ray diffraction（XRD）,and BET surface area measurement.The results showed that the GA had rough surfaces,developed pores,and were mainly amorphous,with small fractions of crystalline quartz and hematite.The surface area of the GA,which consists of many mesopores,was 43.8 m2·g^-1.The kinetic studies revealed that arsenate adsorption on the GA was described by a pseudo-second-order kinetic equation,and the Freundlich isotherm equation fit the arsenate adsorption well（R2=0.994）.The maximum adsorption capacity calculated by the Langmuir isotherm equation for As（Ⅴ） was 5.05 mg·g^-1.Further studies showed that the GA operated well for As（Ⅴ） removal over a broad range in pH from 1.1 to 9.5.The coexistence of HCO_3^- and SO_4^（2-） had no great influence on arsenic adsorption,while the H_2PO_4^- and SiO_3^（2-） showed negative effects.The GA can be regenerated well,and 82% of the original adsorption capacity was maintained after three regeneration cycles.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2018年第1期170-178,共9页
Environmental Science
基金
国家自然科学基金项目(51308009)
北京市教委科技计划项目(KM201510005021)
关键词
反冲洗泥
除砷
颗粒吸附剂
表征
吸附
backwashing residuals
arsenic remove
granular adsorbents
characterization
adsorption
