摘要
为探明竹屑对水溶液中Cu^(2+)、Cd^(2+)和Pb^(2+)的吸附性能,研究了溶液在不同pH值条件下竹屑对Cu^(2+)、Cd^(2+)和Pb^(2+)的吸附动力学过程;并应用等温吸附模型对Cu^(2+)、Cd^(2+)和Pb^(2+)的吸附过程进行了拟合,探讨竹屑对Cu^(2+)、Cd^(2+)和Pb^(2+)的吸附机理。结果表明,在不同pH条件下,竹屑对溶液中的Cu^(2+)、Cd^(2+)和Pb^(2+)吸附都有较好的效果,当溶液的pH=5时吸附效果最好,其次是pH=4、pH=6、pH=3和pH=7;在相同pH条件下,竹屑对溶液中的Cu^(2+)吸附效果最好,其次是Cd^(2+)和Pb^(2+);在不同pH值条件下,Langmuir与Freundlich方程均适于描述竹屑对Cu^(2+)、Cd^(2+)和Pb^(2+)的等温吸附过程,竹屑对Cu^(2+)的等温吸附过程,Freundlich模型对数据的拟合程度略高于Langmuir模型,亦即竹屑的多分子层吸附强于单分子层吸附。竹屑对Cd^(2+)和Pb^(2+)的等温吸附过程,Freundlich模型和Langmuir模型对数据的拟合程度差别不大,亦即竹屑同时存在多分子层吸附和单分子层吸附。竹屑不进行酸化或碱化等活化处理,更不进行碳化处理,只做简单处理后作为重金属的吸附材料,降低了处理成本,避免复杂处理带来二次环境污染,提高了社会效益。
In order to explore the adsorption characters of Cu^2+,Cd^2+and Pb^2+in aqueous solution by bamboo sawdust,the adsorption kinetics of Cu^2+,Cd^2+and Pb^2+were studied under different pH value.The adsorption processes of Cu^2+,Cd2+and Pb^2+were simulated by the isothermal adsorption model,and the adsorption mechanism of bamboo sawdust on Cu^2+,Cd^2+and Pb^2+was investigated.The results showed that under various pH conditions,bamboo sawdust effectively adsorbed the Cu^2+,Cd^2+and Pb^2+of the solution,and the adsorption effect reached the best at pH=5,followed by pH=4,pH=6,pH=3 and pH=7.Under the same pH condition,the adsorption rate of Cu^2+was the highest,followed by Cd^2+and Pb^2+.Under different pH conditions,the Langmuir and Freundlich equations well described the adsorption process of Cu^2+,Cd^2+and Pb^2+by bamboo sawdust.The fitted value of Freundlich model was slightly higher than that of the Langmuir model for the isothermal adsorption process of Cu^2+,i.e.the multi-molecular adsorption of bamboo sawdust was stronger than its single molecule layer adsorption.As for the isothermal adsorption process of bamboo sawdust to Cd^2+and Pb^2+,The fitting results of Freundlich model and Langmuir model was not very different,indicating that there existed simultaneously multi-molecular and single molecular layer adsorption in the bamboo sawdust.The bamboo sawdust can be used as heavy metal adsorption material after simple treatment,requiring no activation such as acidification,alkalization,or carbonization.This may reduce the processing cost,avoid the secondary environmental pollution result from complex processing,and improve the social benefits.
作者
马占青
温淑瑶
MA Zhan-qing;WEN Shu-yao(Hangzhou Vocation and Technical College,Hangzhou 310018,Zhejiang,China;School of Geography,Beijing Normal University,Beijing 100875,China)
出处
《竹子学报》
2018年第4期43-48,共6页
Journal of Bamboo Research
关键词
竹屑
重金属
吸附性能
动力学
Bamboo sawdust
Heavy metal
Adsorption character
Dynamics
