菜粕对水溶液中Cr(Ⅵ)吸附性能研究  

Adsorption behaviors of the rapeseed meal for removing Cr(Ⅵ) from the aqueous solution

作　　者：李松[1] 黎国兰[1] 何登良[1] 

机构地区：[1]绵阳师范学院化学与化学工程学院,四川绵阳621000

出　　处：《安全与环境学报》2013年第4期10-13,共4页Journal of Safety and Environment

基　　金：国家自然科学基金项目(51004066);四川省教育厅课题(07110731)

摘　　要：考察了菜粕对Cr(VI)的吸附热力学和动力学性质。结果表明,溶液pH值为1.2,吸附剂投放量为2 g/L,Cr(VI)质量浓度为50mg/L,反应3 h,菜粕对Cr(VI)的去除率达到90%以上。菜粕对Cr(VI)的吸附行为符合准二级反应动力学模型。Langmuir和Freunlich模型均能较好地拟合菜粕对Cr(VI)的吸附曲线,最大吸附量可达54.6mg/g。吸附前后的红外光谱分析表明,溶液中的Cr(Ⅵ)通过与菜粕表面—OH、—CO—和—CN等基团相互作用而发生吸附。In this paper,we have made a proposal to use rapeseed meal（RM） to adsorb Cr（VI） from the simulated sewage,while exploring with it the thermodynamic and kinetic behaviors of the adsorption for Cr（Ⅵ）.At the same time,we have also made a detailed investigation of the effects of pH value,adsorbent dosage,temperature,initial concentration and contact time on the adsorption process.As a result,all the experimental data of equilibrium isothermal under different temperatures prove to be well fit with Langmuir and Freundlich models.And then,the pseudo-second-order equation was adopted to the analysis of the kinetic data to prove the results in accord with the data demanded for the calculation.To understand the interaction between the adsorbate and the adsorbent,we have used Fourier transform infrared spectroscopy（FTIR） to verify the actual difference of RM involved before and after the adsorption was done.The results demonstrate that the uptake of Cr（Ⅵ） was highly pH dependent and significantly increased correlated with decrease of pH value.It was found that the RM exhibit strong adsorption behaviors for Cr（Ⅵ）,with the percentage removal of Cr（VI） being over 90% under the conditions when the initial chromium concentration was 50 mg/g,the RM dosage was 2 g/L,with the solution pH value of 1.2 and for 3 hours.The data of equilibrium adsorption can well be properly described by using Langmuir and Freunlich adsorption isotherm models.More precisely speaking,the equilibrium constants KL and KF for two models respectively tend to increase with the rise of temperature,which indicate that the higher temperature,the more it is beneficial for enhancing the absorptive capacity of RM for Cr（Ⅵ）.We have also found that the maximum adsorption capacity（qm） of Cr（VI） was 54.6 mg/g at 313 K.The kinetic data have also been proven well fitted with the pseudo-second-order kinetic model,with the correlation coefficient gained by the model being up to 0.999 6.And the calculated equilibrium uptakes

关 键 词：环境工程学 菜粕 CR(VI) 吸附 动力学 

分 类 号：X52[环境科学与工程—环境工程]