摘要
采用硝酸对煤基粉末活性炭进行改性处理,考察不同改性条件下活性炭吸附性能的变化,并将最优改性条件下所得的活性炭用于对垃圾渗滤液的深度处理,考察活性炭的不同投加量和吸附时间等参数对污染物的去除效果。试验结果表明:在硝酸浓度15%、改性温度60℃、改性2 h后,改性活性炭中孔孔径的比例最大,吸附性能最佳;在改性活性炭处理垃圾渗滤液试验中,当活性炭投加量为4 g/150 mL、吸附时间为12 h、溶液pH值为7时,化学需氧量(COD)、氨氮(NH3-N)、总氮(TN)、六价铬(Cr6+)的去除率分别为79.0%、43.3%、52.6%和100%。改性后,活性炭对COD和TN的去除率较改性前分别提高10.1%和17.3%。对COD吸附降解动力学分析发现,改性活性炭12 h内吸附降解COD的反应更符合零级动力学反应。对降解过程进行非线性拟合表明,降解过程可由Logistic函数模型模拟和预测。利用超声波法,在pH值为4.5的酸性条件下超声2 h以上时,对改性活性炭再生后恢复效果较好,以UV254为参考值,再生后处理率相比初次使用时仅降低12%,可重复利用。
The coal based powder activated carbon was modified by nitric acid,the adsorption properties of activated carbon under different modification conditions was investigated the modified activated carbon obtained under the optimal modification conditions was used for the advanced treatment of landfill leachate to investigated the pollutants removal efficiency with varying different parameters such as input dosage and absorption time.The ratio of mesoporous aperture diameter and absorption properties of activated carbon attained the highest after modification 2 h with the concentration of nitric acid 15%and the temperature of modification 60℃.The removal rates of COD,NH3-N,TN and Cr6+were 79.0%,43.3%,52.6%and 100%,respectively,when the dosage of modified activated carbon was 4 g/150 mg/L,the adsorption time was 12 h,and the solution pH of 7.And after modification,the removal rate of COD and TN increased by 10.1%and 17.3%compared with previous activated carbon.It was found that the reaction of adsorption and degradation of COD in 12 h was more consistent with zero order reaction when analyzing the kinetics of COD adsorption and degradation.In addition,the nonlinear fitting of degradation process indicates that the degradation process can be simulated and predicted by Logistic function model.A better regenerative result was achieved by using ultrasonic method with the options of pH was 4.5 and ultrasonic time more than 2 h.Taking UV254 as reference value,the regenerative post-treatment rate was reduced by 12%compared with the initial using which indicated that the nitric acid modified coal-based activated carbon has good regenerative capacity and could be reused.
作者
唐佳伟
师学璐
张春晖
吴笑宇
颜正
潘毅
康晓晗
王永慧
Tang Jiawei;Shi Xuelu;Zhang Chunhui;Wu Xiaoyu;Yan Zheng;Pan Yi;Kang Xiaohan;Wang Yonghui(School of Chemical and Environmental Engineering,China University of Mining and Technology,Beijing 100083,China)
出处
《矿业科学学报》
2019年第3期269-276,共8页
Journal of Mining Science and Technology
基金
“神雾杯”第十一届全国大学生节能减排社会实践与科技竞赛项目
关键词
硝酸
活性炭
吸附
垃圾渗滤液
再生
nitric acid
activated carbon
adsorption
landfill leachate
regeneration
