水杨酸改性稻草秸秆对Cu^2+的吸附研究

Study on adsorption of Cu^2+ by straw modified with salicylic acid

采用水杨酸对稻草秸秆进行改性,研究其对Cu^2+的吸附性能。以制备的吸附剂对Cu^2+的去除率为参考依据,优化吸附剂制备条件,结果显示:稻草秸秆与水杨酸质量比1∶1.5、改性时间120 min、改性温度35℃为最佳制备条件。同时进一步研究吸附剂投加量、吸附温度、吸附时间、溶液初始浓度等因素对吸附效果的影响。当温度为35℃、pH为5.0、吸附时间为90 min时,0.15 g改性吸附剂对15 mg/L的Cu^2+溶液去除率达92.60%。改性稻草秸秆对Cu^2+的吸附过程符合准二级反应动力学方程,用Langmuir和Freundlich吸附等温模型均能描述Cu^2+在改性稻草秸秆上的吸附。

Rice straw was modified by salicylic acid and its adsorption properties for Cu^2+ was studied. Based on the removal rate of Cu^2+ by the prepared adsorbent, the preparation conditions of the adsorbent were optimized. The results showed that the best preparation conditions were as follows: the mass ratio of straw to salicylic acid was 1∶1.5, modified time was 120 min and modified temperature was 35 ℃. The effects of adsorbent dosage, adsorption temperature, adsorption time and initial concentration of solution on the adsorption of Cu^2+ were investigated. When temperature was 35 ℃, pH value was 5.0, adsorption time was 90 min, amount of modified adsorbent was 0.15g, and the concentration of Cu^2+ solution was 15 mg/L, the removal rate of Cu^2+ solution reached 92.60 %. The adsorption process conformed to the quasi-second-order reaction kinetic equation, and both Langmuir and Freundlich model could well describe this adsorption.