麦秆对水中扑草净的吸附性能研究  

The study of prometryn adsorption on the wheat straw

作　　者：任艳真 黄岁樑[1,2] 

机构地区：[1]南开大学环境污染过程与基准教育部重点实验室,天津300457 [2]南开大学环境科学与工程学院,天津市城市生态环境修复与污染防治重点实验室,天津300071

出　　处：《环境污染与防治》2015年第7期27-34,共8页Environmental Pollution & Control

基　　金：国家自然科学基金资助项目(No.51079068);天津市应用基础与前沿技术研究计划(No.15JCYBJC22500);天津市科技计划重点项目(No.09ZCGYSF00400)

摘　　要：农业秸秆富含纤维素、木质素等组分，是良好的吸附材料。采用麦秆作为吸附剂，其对浮油及溶解油具有良好吸附效果。选用麦秆为吸附剂，探究其对扑草净的吸附效果。主要考察麦秆粒径、投加量、振荡频率、扑草净初始质量浓度4种因素对吸附的影响，研究麦秆对扑草净的吸附等温线和吸附动力学过程，并采用正交实验对影响吸附的因素进行优化。结果表明：（1）麦秆可有效降低废水中扑草净浓度，在振荡频率150r／min、麦秆粒径250～500μm、投加量0．5000g、吸附300min时，扑草净初始质量浓度由5．20mg／L降至3．22mg／L，去除率为38．08％。（2）单因素吸附平衡实验表明，随麦秆粒径增加（150～4000μm），其比表面积减小，平衡吸附量随之减小，麦秆粒径150～250pm时平衡吸附量为0．1920mg／g，显著大于1700～4000μm时的平衡吸附量（O．0593mg／g）}随麦秆投加量增加（O．1000～1．0000g）。去除率随之提高，平衡吸附量与之相反，0．1000g投加量时平衡吸附量为0．2220mg／g；随着振荡频率加剧，麦秆在水中扩散增强，与扑草净碰撞几率增加，振荡频率250r／min时平衡吸附量为0．1910mg／g；随扑草净初始质量浓度增加（1.03～6．18mg／L），平衡吸附量随之增加，初始质量浓度为6．18mg／L，平衡吸附量为0．2260mg／g。（3）分别以Henry型、Langmuir型、Freundlich型吸附等温式进行拟合，资料表明。以Henry型吸附等温式较适宜描述该吸附过程。（4）采用伪一级动力学方程、伪二级动力学方程、Elovich经验方程、颗粒内扩散方程分析吸附动力学过程，以伪二级动力学方程较符合。（5）在振荡频率为150r／min、初始质量浓度为2．00mg／L、麦秆粒径为250--500μm、投加量为0．7000g时，扑草净最佳去除率为47．80％。Crop straw is a good adsorption material because it is rich in cellulose, lignin components. Wheat straw was used as adsorbent,which could effectively adsorb the oil in water. Adsorption of prometryn by wheat straw was investigated. Factors influencing adsorption of prometryn onto wheat straw, such as particle size of straw, optimum dosage of straw,oscillation frequencies and initial dissolved prometryn concentrations were studied. Adsorption isotherm and kinetics were studied as well. And levels of various factors and their combination influencing adsorption were optimized by the orthogonal experimental method. The results showed that： （1） The dissolved prometryn con- centration of 5.20 mg/L reduced to 3.22 mg/L,with its removal rate of 38.08%0 when the oscillation frequency was 150 r/min,straw particle size 250-500μm,dosage of straw 0.500 0 g in 300 min. （2） The adsorption capacity of straw decreased with increasing its grain size within the range of 150-4 000μm due to a decrease of specific area. The ad- sorption quantities were 0.192 0 mg/g and 0.059 3 mg/g,when the size of straw were 150-250 /xm and 1 700-4 000 μm, respectively. With the increase of straw dosage （0.100 0-1.000 0 g）, the removal rate increased, but adsorption ca- pacity decreased,the adsorption capacity was 0.222 0 mg/g when the dosage was 0.100 0 g. The adsorption quantity of 0.130 0 mg/g to 0.191 0 mg/g was observed when the oscillation frequency changed from 0 r/min to 250 r/min. With the increase of initial concentrations of prometryn （1.03-6.18 rag/L）, the adsorption quantity increased, and the ad- sorption quantity was 0.226 0 mg/g when the initial prometryn concentration was 6.18 mg/L. （3） The adsorption equilibrium data were fitted with the Henry,Langmuir and Freundlich equations,with the Henry being the best. （4） This kinetic adsorption data was fitted with pseudo-secondary dynamics, first-order kinetics equation, Elovich equation and Intraparticle diffusion model, with the first one being the best. （5�

关 键 词：扑草净 麦秆 吸附 动力学 

分 类 号：X703[环境科学与工程—环境工程]