改性烟草秸秆生物炭制备及其对重金属Pb2+吸附  

Chemical Modified Biochar from Tobacco Straw:Adsorption Process of Pb2+in Simulated Contaminated Waste Water

作　　者：李会端[1] 常国琼 徐丽男 罗盛铃 刘晓勇 LI Huiduan;CHANG Guoqiong;XU Linan;LUO Shengling;LIU XiaoYong

机构地区：[1]楚雄师范学院资源环境与化学学院,云南楚雄675000

出　　处：《化工设计通讯》2025年第4期96-104,共9页Chemical Engineering Design Communications

基　　金：国家自然科学金项目(12263001);云南省基础研究计划项目(202101BA070001-181);省级大学生创新创业训练计划项目(S202311391059,S202311391043);楚雄师范学院课程思政资源库建设项目(SZZYK10)。

摘　　要：该论文聚焦重金属污染土壤改性、水体富营养化修复和农林固体废弃物的资源化利用,以云南烟草秸秆为原料制备改性生物炭吸附剂,研究其对模拟污染水体和土壤中Pb(Ⅱ)的吸附。首先,通过限氧碳化和化学改性制备云南烟草秸秆生物炭吸附剂;其次,分别设计单因素和设计响应面分析方案优化吸附过程;最后,完成改性烟草秸秆生物炭对Pb(Ⅱ)的化学分析。烟草秸秆500℃限氧炭化2 h,分别用0.1 mol·L^(-1) KMnO_(4)(aq)和1%NaOH(aq)浸泡制备两种改性烟草秸秆生物炭tsb-Mn和tsb-OH。响应面分析获得多元回归模型:R=+97.84+0.95A+0.48B-0.58C+0.29D+0.12AB+0.67AC+0.15AD-0.067BC+0.66BD-0.45CD-0.74A^(2)-1.72B^(2)-0.97C^(2)-1.66D^(2)。ANVOA分析模型极其显著(P<0.0001),R^(2)=0.9445和Adj.R^(2)=0.8891相差0.0554,拟合模型可进一步优化。各响应因子显著性顺序:B(Pb^(2+)初始浓度)>C(吸附温度)>A(吸附剂用量)>D(吸附时间)。根据多元回归模型预测的最佳吸附条件开展验证性实验,吸附剂用量20 mg,Pb^(2+)初始浓度500 mg·L^(-1),吸附温度30℃、吸附时间45 min,实验测得Pb^(2+)吸附率高达99.25%,与理论预测值99.36%相吻合。吸附过程化学分析:tsb-Mn和tsb-OH对Pb^(2+)吸附均符合Freundlich等温吸附类型和准二级动力学方程,而tsb-OH对Pb^(2+)的吸附以化学吸附为主。本论文开发了一种经济高效、环境友好的生物吸附剂,对污染水体和土壤中重金属Pb(Ⅱ)具有良好的吸附性能;论文研究关注生态环境,勇于学科担当,培养社会责任。[Objective]This paper focuses on the modifi cation of heavy metal contaminated soil,the remediation of eutrophication of water bodies,and the resource utilization of agricultural and forestry solid waste.The modifi ed Biochar adsorbent was prepared with Yunnan tobacco straw as the raw material to study its adsorption of Pb(Ⅱ)in simulated contaminated soil and water bodies.[Methods]Firstly,Yunnan tobacco straw Biochar adsorbent was prepared by oxygen limited carbonization and chemical modifi cation;Secondly,the adsorption process was optimized by single factor and response surface analysis;Finally,the chemical analysis of Pb(Ⅱ)process of modifi ed tobacco straw Biochar was completed.[Results]Two kinds of modified tobacco straw Biochar,tsb-Mn and tsb-OH,were prepared by carbonization of tobacco straw at 500℃for 2 h under oxygen limitation,and soaked in 0.1 mol·L^(-1) KMnO_(4)(aq)and 1%NaOH(aq),respectively.Multiple regression model was obtained by response surface analysis:R=+97.84+0.95A+0.48B-0.58C+0.29D+0.12AB+0.67AC+0.15AD-0.067BC+0.66BD-0.45CD-0.74A^(2)-1.72B^(2)-0.97C^(2)-1.66D^(2).The ANVOA analysis indicated that the model was extremely signifi cant(P value<0.0001),with a difference of 0.0554 between R^(2)=0.9445 and Adj.R^(2)=0.8891.The fi tting model could be further optimized.The signifi cance order of each response factor is:B(Pb^(2+)initial concentration)>C(adsorption temperature)>A(adsorbent dosage)>D(adsorption time).Confi rmatory experiment was designed based on the optimal adsorption conditions predicted by the multiple regression model.The adsorbent dosage was 0.02 g,the initial concentration of Pb^(2+)was 500 mg·L^(-1),the adsorption temperature and time were 30℃and 45 minutes.The experimental results showed that the adsorption rate of Pb^(2+)was 99.25%,which was consistent with the theoretical prediction value of 99.36%.Chemical analysis of adsorption process:The adsorption of Pb^(2+)by tsb-Mn and tsb-OH conforms to the Freundlich isotherm adsorption type and quasi second-order kinetic

关 键 词：烟草秸秆生物炭 化学改性 Pb(Ⅱ)吸附 热力学 动力学 

分 类 号：TQ424[化学工程] X703[环境科学与工程—环境工程]