铅钝化条件下牛粪最佳改性条件筛选及其吸附特性
Screening the Optimal Modification Condition for Cattle Manure under the Condition of Pb Passivation and Its Adsorption Characteristics Research
李喜彦 1吴景贵1
作者信息
- 1. 吉林农业大学资源与环境学院,吉林长春130118
- 折叠
摘要
[目的]研究改性牛粪去除水溶液中铅的最佳条件及其吸附特性,为其在农业生产中的实际应用提供理论支持.[方法]以牛粪为原料,利用KOH、HNO3、柠檬酸对牛粪进行改性,制备重金属吸附剂,考察了改性剂浓度、温度、时间和固液比对水溶液中铅去除效果的影响,并采用正交试验研究3种改性剂的最佳制备条件.利用牛粪制备的改性剂对水溶液中铅进行吸附试验.[结果] KOH的最佳改性条件是浓度0.4 mol/L,温度50℃,时间150 min,固液比1∶10;HNO3的最佳改性条件是浓度0.8 mol/L,温度50℃,时间120 min,固液比1∶15;柠檬酸的最佳改性条件是浓度0.8 mol/L,温度30℃,时间30 min,固液比1∶10.改性牛粪和未改性牛粪对水溶液中铅的吸附等温线均符合Freundlich方程,说明二者对水溶液中铅离子的吸附属于多分子层吸附过程,改性牛粪对水溶液中铅动力学吸附符合二级动力学模型.[结论]KOH、HNO3和柠檬酸改性牛粪对水溶液中铅的吸附性能均好于未改性牛粪,吸附强度从大到小依次为柠檬酸、HNO3、KOH、未改性牛粪.
Abstract
[Objective] To research the optimal condition for Pb removal from aqueous solution of modified cattle manure and its adsorption research,and to provide theoretical support for the practical application in agricultural production.[Method] With cattle manure as raw materials,KOH,HNO3 and citric acid were used to prepare cattle manure into the adsorbent of heavy metals.Effects of modifier concentration,modification temperature,modification time and solid-liquid ratio on the removal rate of Pb in aqueous solution were researched.The optimal conditions for the three modifiers were determined by orthogonal experiment.Finally,modifier was used in aqueous solution for Pb adsorption research.[Result] The optimal modified condition for KOH was as follows:0.4 mol/L KOH concentration,150 min time,and 1:10 solid-liquid ratio.The optimal modified condition for HNO3 was 0.8 mol/L HNO3 concentration,50 ℃ temperature,120 min time,and 1 ∶ 15 solid-liquid ratio.The optimal modified condition for citric acid was 0.8 mol/L concentration,30 ℃ temperature,30 min time and 1∶ 10 solid-liquid ratio.The adsorption isotherms of modified cattle manure and unmodified cattle manure accorded with the Freundlich equation,indicating that the adsorption of lead in aqueous solution was the process of maltilayer adsorption.Modified cattle manure adsorption dynamics of Pb2+ in aqueous solution accorded with the secondary dynamic model.[Conclusion] Modified cattle manure by KOH,HNO3 and citric acid had higher adsorptive property to Pb in aqueous solution than the unmodified cattle manure.The adsorptive property from high to low was in the order of citric acid,HNO3,KOH and unmodified cattle manure.
关键词
牛粪/铅/正交试验/吸附等温/二级动力学Key words
Cattle manure/Pb/Orthogonal test/Adsorption isotherm/The secondary dynamic model引用本文复制引用
基金项目
国家科技支撑计划项目(2013BAC09B01)
国家科技支撑计划项目(2012BAD14B05)
吉林省科技厅重点科技成果转化项目(2013-0303-035NY)
出版年
2016
国家科技期刊平台
NSTL
维普
万方数据