镧改性木槿皮吸附剂制备及对废水中磷的吸附  

A New Adsorbent for Phosphorus Removal From Bark of Hibiscus syriacus Modified by Lanthanum

作　　者：倪琳洁 邱欢 刘晓玲[3] 雷燕 张可 罗鸿兵[1,5] 程琳 范良千[1,5] 陈伟 NI Lin-jie;QIU Huan;LIU Xiao-ling;LEI Yan;ZHANG Ke;LUO Hong-bing;CHENG Lin;FAN Liang-qian;CHEN Wei(Department of Municipal Engineering,College of Civil Engineering,Sichuan Agricultural University,Dujiangyan 611830,China;College of Environmental Science and Engineering,Nankai University,Tianjin 300071,China;Department of Information Engineering,Sichuan Water Conservancy Vocational College,Chengdu 611231,China;Environmental Monitoring Station of Jintang County,Chengdu 610400,China;Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction,Sichuan Agricultural University,Chengdu 611830,China)

机构地区：[1]四川农业大学土木工程学院市政工程系,四川都江堰611830 [2]南开大学环境科学与工程学院,天津300071 [3]四川水利职业技术学院信息工程系,四川成都611231 [4]四川省成都市金堂县环境监测站,四川成都610400 [5]四川农业大学四川省高等学校村镇建设防灾减灾工程研究中心,四川成都611830

出　　处：《生态与农村环境学报》2021年第2期234-241,共8页Journal of Ecology and Rural Environment

基　　金：四川省科技厅重点研发项目(2018SZ0302);四川省成都市科技局重点研发支撑计划(2019-YF05-00839-SN;2015-HM01-00325-SF);2018年四川农业大学本科生科研兴趣培养计划(2018512)。

摘　　要：以木槿皮作为原料,利用氯化镧对其进行改性,制备一种新的磷吸附材料。采用单因素法确定吸附剂的最佳改性条件,研究pH值、吸附剂投加量、吸附时间、吸附温度对磷的吸附性能的影响,结果表明:(1)木槿皮的最佳改性条件为:w(氯化镧)为7%、焙烧温度300℃、焙烧时间2.5 h;(2)初始ρ(磷)为5 mg·L^(-1),pH值为7,投加量为0.35 g时吸附效果最好,磷去除率达到94.99%;(3)吸附时间为130 min时改性木槿皮对磷的吸附达到饱和,不同温度下镧改性木槿皮对磷的吸附方式均符合伪二级动力学方程;(4)Langmuir等温方程拟合效果更佳,吸附反应为单分子层吸附,温度为288、298和308 K时镧改性木槿皮吸附剂对磷的最大吸附量分别为1.54、1.55和1.63 mg·g^(-1);(5)吸附热力学结果显示自由能变(ΔG^(θ))<0、焓变(ΔH^(θ))>0、熵变(ΔS^(θ))>0,镧改性木槿皮对磷的吸附是一个自发熵增的吸热过程,升温有利于反应进行,属于化学吸附。Based on the bark of Hibiscus syriacus,a new phosphorus adsorbent was modified by lanthanum chloride to remove phosphorus from wastewater.The mono-factor method was used to determine the optimal modification conditions of the adsorbent.The effects of pH,adsorbent amount,adsorption time and adsorption temperature were investigated.Results show that:(1)The optimal modification conditions of the bark of Hibiscus syriacus were the lanthanum chloride solution concentration of 7%,the calcination temperature of 300℃and the roasting time of 2.5 hours.(2)When the initial concentration of phosphorus was 5 mg·L^(-1),the solution acidity was pH 7 and the optimum dosage was 0.35 g,the best adsorption phosphorus removal rate reached to 94.99%.(3)When the adsorption time was 130 min,the adsorption reaction was in equilibrium.The adsorption modes of bark of Hibiscus syriacus modified by lanthanum chloride were all determined to the pseudo-second-order kinetic equation at different temperatures.(4)The Langmuir equation was suitable to describe the adsorption reaction which belonged to single molecule layer adsorption.At temperatures of 288,298 and 308 K,the maximum adsorption capacity of modified bark of Hibiscus syriacus was 1.54,1.55 and 1.63 mg·g^(-1),respectively.(5)Adsorption thermodynamic analysis results show that theΔG^(θ),ΔHθandΔS^(θ)was<0,>0 and<0,respectively,which means that the adsorption reaction was promoted when the temperature rose.These results also indicate that adsorption reaction using bark of Hibiscus syriacus modified by lanthanum chloride was a spontaneous,entropy increasing and endothermic process and belonged to the chemical adsorption.This study provides a theoretical reference for treating phosphorous wastewater by using bark of Hibiscus syriacus modified by lanthanum chloride.

关 键 词：木槿皮 镧改性 吸附 磷去除 

分 类 号：X52[环境科学与工程—环境工程] X712