热处理富钙凹凸棒黏土吸附磷的影响因素  

Factors Influencing the Phosphorus Adsorption Capacity of Thermally Modified Calcium-Rich Attapulgite

作　　者：孔明[1] 尹洪斌[2] 纪中新 张毅敏[1] 彭福全[1] 

机构地区：[1]环境保护部南京环境科学研究所,江苏南京210042 [2]中国科学院南京地理与湖泊研究所,湖泊与环境国家重点实验室,江苏南京210008 [3]河海大学环境学院,江苏南京210098

出　　处：《环境科学研究》2017年第4期615-620,共6页Research of Environmental Sciences

基　　金：中央级公益性科研院所基本科研业务费;国家水体污染控制与治理科技重大专项(2012ZX07101-007)

摘　　要：以800℃热处理富钙凹凸棒黏土(记为NCAP800)为研究对象,通过批处理试验和动态试验研究了不同因素(pH、竞争离子、柠檬酸)对NCAP800吸附磷的能力的影响.结果表明:酸性条件对磷的吸附能力无影响,碱性条件(pH>9)对NCAP800的磷吸附具有一定的抑制作用,pH对NCAP800磷吸附能力的影响主要通过改变黏土矿物中可交换钙、镁含量与矿物表面Zeta电位.阴离子中HCO_3^-对磷的抑制作用较为显著,尤其当ρ(HCO_3^-)为5~20 mg/L时抑制作用最为显著,其次是SO_4^(2-),NO_3^-和Cl^-对磷的吸附无抑制作用.HCO_3^-和SO_4^(2-)抢夺钙的结合位点,从而降低了NCAP800对磷的吸附能力.低浓度(c为0~5 mmol/L)的柠檬酸对磷的吸附抑制作用较弱,高浓度(c为5~50 mmol/L)的柠檬酸对磷的抑制作用较为显著,柠檬酸对磷的抑制机制同样是通过竞争NCAP800表面的磷吸附位点.研究显示,NCAP800在碱性条件下对磷具有较好的吸附作用,HCO_3^-和SO_4^(2-)及高浓度柠檬酸均会抑制NCAP800对磷的吸附.The influencing factors（ e. g. pH,competing anions and citric acid） of phosphorus adsorption capacity of 800 ℃-heated calciumrich attapulgite were studied. The results showed that pH had no influence on phosphorus adsorption capacity in acidic conditions,while in alkaline conditions,pH had a certain effect on the phosphorus adsorption when it was in the range of 8-10. The effect of pH on phosphorus adsorption capacity was mainly via changing the amount of exchangeable metals（ Mg and Ca） and the Zeta potential. It was noted that HCO3^-inhibited phosphorus adsorption of NCAP800 mostly when the concentration of HCO3^-was 5-20 mg/L,followed by SO4-（2-）,NO3^-and Cl-,which had no effect on phosphorus adsorption. The inhibiting effect was mainly through competing adsorption sites,which reduced phosphorus adsorption capacity of NCAP800. The low citric acid concentration（ 0-5 mmol/L） had a slightly lower effect on phosphorus adsorption than that of high citric acid concentrations（ 5-50 mmol/L）,resulting from the inhibition mechanism of competing adsorption sites on the NCAP800 surface.

关 键 词：富钙凹凸棒 热处理 磷 吸附效率 影响因素 

分 类 号：X703[环境科学与工程—环境工程]