摘要
在城市雨水径流中,溶解性有机氮(DON)约占总氮含量的47%,大量DON排入水体会造成城市水体黑臭,同时冬季融雪剂会抑制DON转化,导致DON去除率较低.本研究通过向生物滞留系统填料中添加铁改性生物炭(FBC),探讨添加融雪剂和不同运行条件对DON去除效率及机制的影响.结果表明,FBC显著提升了生物滞留系统对DON的去除能力.FBC组在未添加融雪剂,且降雨时长为60 min,降雨强度为60mL·min^(-1)时,对DON的去除率可达78.23%,比石英砂组提高了24.60%.添加融雪剂抑制了DON的去除效果,在此运行条件下,去除率降低了15.85%.此外,FBC通过表面氧化铁活性官能团及Fe^(3+)的作用,促进细菌产生了更多的蛋白酶、脲酶、脱氢酶、硝酸盐还原酶和亚硝酸盐还原酶等氮循环相关酶,酶活性比石英砂组提高了23.16%~572.8%,从而促进了DON的转化.总体而言,将FBC加入生物滞留系统的填料层,能够吸附部分DON,同时促进DON矿化,在融雪剂胁迫下,FBC吸附Na^(+),缓解了融雪剂对氮素转化的抑制作用,实现了DON的高效去除.该研究为冬季生物滞留系统去除融雪径流中DON提供了理论依据.
In urban stormwater runoff,approximately 47%of the total nitrogen content was dissolved organic nitrogen(DON),which can contribute to the formation of urban black and odorous water bodies when discharged into water bodies in large quantities.Moreover,snowmelt agents in winter will inhibit the transformation of DON,resulting in a low removal efficiency of DON.In this study,iron-modified biochar(FBC)was used as the filler in a bioretention system to investigate the impact on the DON removal efficiency and mechanism in the presence of snowmelt agents and under different operating conditions.The results showed that FBC significantly enhanced the removal efficiency of DON in the bioretention system.When the stormwater duration was 60 min and the intensity was 60 mL·min^(-1),the removal efficiency of DON in FBC were 78.23%without the addition of snowmelt agents,which was 24.60%higher than that of the quartz sand group.The addition of snowmelt agents inhibited the removal of DON,and the removal efficiency decreased by 15.85%.In addition,FBC promoted the production of nitrogen cycle-related enzymes,such as protease,urease,dehydrogenase,nitrate reductase and nitrite reductase.This promotion was facilitated by surface iron oxide reactive functional groups and Fe^(3+)within the FBC.The enzyme activities were increased by 23.16%~572.8%compared with those of the quartz sand group,which in turn promoted the conversion of DON.Overall,incorporating FBC into bioretention system fillers stimulated the adsorption of DON and promoted its mineralization,resulting in the efficient removal of DON under snowmelt agents stress.This study offers a theoretical basis for the removal of DON from snowmelt runoff in winter bioretention systems.
作者
陈友媛
王丹
王磊
张孝桢
李雪薇
赵昊昀
李晓涵
刘恒阳
CHEN Youyuan;WANG Dan;WANG Lei;ZHANG Xiaozhen;LI Xuewei;ZHAO Haoyun;LI Xiaohan;LIU Hengyang(College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100;Key Laboratory of Marine Environment and Ecology,Ministry of Education,Ocean University of China,Qingdao 266100;Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100;North China Municipal Engineering Design&Research Institute Co.,Ltd,Tianjin 300000)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第10期197-205,共9页
Acta Scientiae Circumstantiae
基金
国家自然科学基金项目(No.42177053)。
关键词
生物滞留系统
铁改性生物炭
融雪剂
有机氮
矿化
bioretention systems
iron-modified biochar
snowmelt agent
dissolved organic nitrogen
mineralization
