摘要
为探讨不同农业废弃物对废水中Cd^2+和Pb^2+吸附特征,研究了花生秆(HG)、葵花盘(KP)、棉花壳(MK)和棉花秆(MG)粉末在不同投加量、溶液pH、吸附时间、溶液初始浓度和离子强度条件下对废水中Cd^2+和Pb^2+的吸附特征。结果表明,随着废弃物投加量增加,单位质量花生秆、葵花盘和棉花壳对Cd^2+和Pb^2+的吸附量呈幂函数或对数下降(P<0.05);随着溶液pH升高,4种废弃物对Cd^2+和Pb^2+的吸附量均呈先增加后基本保持不变的趋势。4种材料对Cd^2+和Pb^2+的动力学吸附过程可用准二级动力学模型进行描述。在等温吸附模型中,Freundlich模型更适用于棉花秆对Cd^2+和Pb^2+的吸附过程,而Langmuir模型更适用于其他3种材料的吸附过程。4种材料对Cd^2+的最大吸附量为59.18~93.13 mg·g^-1,对Pb^2+的最大吸附量为106.43~167.73 mg·g^-1。共存离子Na+的存在可显著降低4种材料对Cd^2+的吸附量和棉花秆对Pb^2+的吸附量(P<0.05)。
In order to discuss the adsorption characteristics of different agricultural wastes on Cd^2+and Pb^2+in wastewater,the powder of peanut straw(HG),sunflower faceplate(KP),cotton husk(MK)and cotton straw(MG)were selected for the study.The studied adsorption characteristics include dosage,solution pH,adsorption time,initial solution concentration and ionic strength.The results show that the adsorption capacities of Cd^2+and Pb^2+by the peanut straw,sunflower faceplate and cotton husk decreased exponentially or logarithmically when the dosage increased from 0.025 g to 0.200 g(P<0.05).With the increasing pH,the adsorption capacities of Cd^2+and Pb^2+increased initially and then remain unchanged.Those of peanut straw and cotton husk are significantly higher than the other two materials(P<0.05).The sorption kinetics of Cd^2+and Pb^2+on the four materials follows the pseudo-second order model.Isothermal adsorption of Cd^2+and Pb^2+by HG,KP,and MK fitted well with Langmuir equation,while Freundlich equation is more suitable for the MG.The maximum adsorption capacity of the four materials on Cd^2+and Pb^2+was 59.18-93.13 mg·g^-1 and 106.43-167.73 mg·g^-1,respecrtively.The existence of Na+can significantly reduce the adsorption capacities on Cd^2+by the four materials and on Pb^2+by cotton straw(P<0.05).
作者
杨岚清
张世熔
彭雅茜
王贵胤
徐小逊
YANG Lan-qing;ZHANG Shi-rong;PENG Ya-xi;WANG Gui-yin;XU Xiao-xun(College of Environmental Sciences,Sichuan Agricultural University,Chengdu 611130,China;Sichuan Provincial Key Laboratory of Soil Environmental Protection,Chengdu 611130,China)
出处
《生态与农村环境学报》
CAS
CSCD
北大核心
2020年第11期1468-1476,共9页
Journal of Ecology and Rural Environment
基金
四川省重点研发项目(2019YFN0020)。
关键词
镉
铅
吸附
花生秆
葵花盘
棉花壳
棉花秆
cadmium
lead
adsorption
peanut straw
sunflower faceplate
cotton husk
cotton straw
