浒苔生物炭对雨水径流中氨氮的吸附特性及吸附机制  

Effect of Enteromorpha prolifera Biochar on the Adsorption Characteristics and Adsorption Mechanisms of Ammonia Nitrogen in Rainfall Runoff

作　　者：陈友媛[1,2,3] 李培强 李闲驰 孙萍 赵新月[1] 李洁 李晋 辛至然 CHEN You-yuan;LI Pei-qiang;LI Xian-chi;SUN Ping;ZHAO Xin-yue;LI Jie;LI Jin;XIN Zhi-ran(College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;Key Laboratory of Marine Environment and Ecology,Ministry of Education,Ocean University of China,Qingdao 266100,China;Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100,China;Qingdao No.9 High School,Qingdao 266100,China)

机构地区：[1]中国海洋大学环境科学与工程学院,青岛266100 [2]中国海洋大学海洋环境与生态教育部重点实验室,青岛266100 [3]中国海洋大学山东省海洋环境地质工程重点实验室,青岛266100 [4]山东省青岛第九中学,青岛266100

出　　处：《环境科学》2021年第1期274-282,共9页Environmental Science

基　　金：山东省自然科学基金项目(ZR2019MD033)。

摘　　要：为探究生物滞留池填料(浒苔生物炭)处理雨水径流氨氮(NH+4-N)的去除效果及机制,进行室内批量吸附实验,在对浒苔生物炭进行碱改性(1、2和3 mol·L^(-1)NaOH改性,分别标记为BC1、BC2和BC3)基础上,开展改性前后浒苔生物炭对NH+4-N吸附性能研究.结果表明:①适宜浓度的碱改性提高了浒苔生物炭的比表面积和表面微观结构,增加了O元素含量,丰富了表面官能团,其中BC2改性效果最好.②浒苔生物炭对NH+4-N的吸附在pH值9.0和生物炭投加量0.5 g·L^(-1)时,吸附量最大,BC1和BC2的吸附量比BC分别提高6.4%和10.8%,BC3则降低13.7%,BC2吸附效果最好,饱和吸附量达16.76 mg·g^(-1).③浒苔生物炭对NH+4-N的吸附机制为单分子层的化学吸附,吸附过程受到生物炭的高pH值、孔隙的静电吸引以及表面羟基(—OH)、羧基(—COOH)和碳氧单键(C—O)等官能团的络合氧化等的促进作用.综上所述,适量的NaOH来改性浒苔生物炭能够提高对NH+4-N的吸附效果,可作生物滞留池的填料来去除NH+4-N污染.In order to study the performance and mechanisms of bioretention pond media(Enteromorpha prolifera biochar)for NH+4-N removal in rainfall runoff,three kinds of alkali modified biochars(marked as BC1,BC2,and BC3)were prepared with various concentrations of NaOH solution(1,2,and 3 mol·L^(-1))to explore their adsorption performance for NH+4-N.The results showed that:①Appropriate modifications of the NaOH concentration increased the specific surface area and surface microstructure of biochar,with the content of O and the surface functional groups being enriched.In addition,BC2 possessed the best adsorption performance.②The adsorption capacity reached a maximum when the pH was 9.0 and the dosage of biochar was 0.5 g·L^(-1).Compared with BC,the adsorption capacity of BC1 and BC2 increased by 6.4%and 10.8%,respectively,while BC3 decreased by 13.7%.Moreover,BC2 had an optimal adsorption efficiency with a saturated adsorption capacity of 16.76 mg·g^(-1).③The adsorption mechanism of biochar belonged to chemical adsorption with a monomolecular layer.The adsorption process was promoted by the high pH of biochar,the electrostatic attraction of biochar pores,the complexation and oxidization of the functional groups of hydroxyl(—OH),carboxyl(—COOH),and carbon-oxygen single bond(C—O).To sum up,the proper amount of NaOH to modify biochar can improve the adsorption performance of NH+4-N,and the modified biochar can be used as media of the bioretention pond to remove NH+4-N.

关 键 词：生物滞留池 浒苔生物炭 氨氮 吸附特性 吸附机制 

分 类 号：X131.2[环境科学与工程—环境科学] X52[环境科学与工程—环境工程]