摘要
采用平衡法研究膨润土和腐殖质对毒死蜱和三唑磷的吸附规律及影响因素.结果表明,腐殖质对2种农药的吸附能力均大于膨润土,毒死蜱和三唑磷在腐殖质上的吸附行为均可用Freundlich模型和Langmuir模型描述,相关系数分别为:R2(毒死蜱)0.9964和0.9963;R2(三唑磷)0.9989和0.9924;膨润土对2种农药的等温吸附线可用Langmuir模型拟合,相关系数为:R2=0.9957(毒死蜱)、R2=0.9989(三唑磷).pH条件、吸附时间和温度均对吸附有影响.腐殖质、膨润土混合吸附剂对2种农药的吸附平衡时间分别为:毒死蜱12h,三唑磷6h.腐殖质﹕膨润土质量比分别达12%和14%时对三唑磷和毒死蜱的吸附最为强烈并趋于饱和.通过计算不同温度各热力学参数ΔG、ΔH和ΔS,理论上证实该吸附为一自发的放热过程,在pH=6.0,温度为15℃时,吸附效果最佳.
The adsorption of chlorpyrifos and triazophos on bentonite and humus was investigated by using the equilibrium oscillometry.The adsorption capacity of chlorpyrifos and triazophos on humus was great higher than bentonite at the same concentration.Equilibrium data of Langmuir,Freundlich isotherms showed significant relationship to the adsorption of chlorpyrifos and triazophos on humus（chlorpyrifos：R2 0.996 4,0.996 3;triazophos：R2 0.998 9,0.992 4）.Langmuir isotherm was the best for chlorpyrifos and triazophos on bentonite（chlorpyrifos：R2 = 0.995 7,triazophos：R2 = 0.998 9）.The pH value,adsorption equilibrium time and temperature were the main factors affecting adsorption of chlorpyrifos and triazophos on bentonite and humus.The adsorption equilibrium time on mixed adsorbent was 12h for chlorpyrifos and 6h for triazophos respectively.The mass ratio of humus and bentonite was 12% and 14% respectively,the adsorption of chlorpyrifos and triazophos was the stronglest and tended to saturation.At different temperatures by calculating the thermodynamic parameters ΔG,ΔH and ΔS,confirmed that the adsorption reaction was a spontaneous exothermic process theoretically.The adsorption was the best when the pH value was 6.0 and the temperature was 15℃.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2010年第11期2699-2704,共6页
Environmental Science
基金
国家林业局"948"项目(2008-4-40)
江苏省重点自然科学基金项目(BK2001208)
关键词
毒死蜱
三唑磷
膨润土
腐殖质
吸附
影响因素
chlorpyrifos
triazophos
bentonite
humus
adsorption
influencing factors
