典型城市居民集中区初期降雨径流污染特征和生物炭对其氮磷去除效果研究  

Pollution Characteristics of Initial Rainfall Runoff in Typical Urban Residential Areas and Removal Efficiency of Nitrogen and Phosphorus by Biochar

作　　者：张瀚文 张志勇[2,3] 郭文景 王小治 刘海琴[2,3] 张迎颖[2,3] 周庆 ZHANG Hanwen;ZHANG Zhiyong;GUO Wenjing;WANG Xiaozhi;LIU Haiqin;ZHANG Yingying;ZHOU Qing(School of Environmental Science and Engineering,Yangzhou University,Yangzhou 225127,China;Institute of Agricultural Resources and Environment,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;Key Laboratory of Agro-Environment in downstream of Yangtze Plain,Ministry of Agriculture and Rural Affairs,Nanjing 210014,China)

机构地区：[1]扬州大学环境科学与工程学院,江苏扬州225127 [2]江苏省农业科学院农业资源与环境研究所,江苏南京210014 [3]农村农业部长江下游平原农业环境重点实验室,江苏南京210014

出　　处：《安全与环境工程》2022年第2期120-131,150,共13页Safety and Environmental Engineering

基　　金：水体污染控制与治理科技重大专项项目(2017ZX07203003)。

摘　　要：居民集中区初期降雨径流是城市面源污染的重要来源之一,其主要污染物包括总氮(TN)、总磷(TP)、硝态氮(NO;-N)等,可引发受纳水体富营养化,从而对城市居民集中区的水体环境安全和城市景观造成危害。以典型城市(无锡)居民集中区为研究对象,采用现场监测的方式重点开展了典型城市居民集中区不同下垫面初期降雨径流中主要污染物浓度和污染负荷等研究,并通过多途径表征、吸附动力学、热力学等方法研究了原生物炭(BC)、改性铁生物炭(BC-Fe)、磁性改性铁生物炭(BC-Fe_(3)O_(4))等不同生物炭材料对典型城市居民集中区初期降雨地表径流中主要污染物的吸附性能和削减效果。结果表明:典型城市居民集中区初期降雨地表径流中主要污染物为氮和磷,不同下垫面类型(交通主干线、居民区内道路、屋面、公园绿地、停车场)地表径流中单位面积产生的TN和TP污染负荷量分别为4.17 kg/(hm^(2)·a)、2.82 kg/(hm^(2)·a)、0.88 kg/(hm^(2)·a)、0.69 kg/(hm^(2)·a)、0.62 kg/(hm^(2)·a)和0.78 kg/(hm^(2)·a)、0.56 kg/(hm^(2)·a)、0.13 kg/(hm^(2)·a)、0.06 kg/(hm^(2)·a)、0.18 kg/(hm^(2)·a),交通主干线地表径流中产生的单位面积污染负荷量最高,但由于居民区内道路汇水面积是交通主干线的4.76倍,故居民区内道路地表径流中产生的TN和TP总污染负荷量最高;BC-Fe材料对污染物的吸附效果最佳,而BC-Fe_(3)O_(4)材料可实现吸附剂的二次回收利用;在弱酸性条件下,3种生物炭材料对溶液中NO_(3)^(-)-N和PO_(4)^(3-)的吸附容量最高,其吸附规律采用准二级动力学方程和Freundlich热力学模型的拟合效果较优;BC-Fe材料对实际污染水体中TN和TP的吸附容量最高可达24.24 mg/g和3.58 mg/g,所需添加量最少,使用成本最低,但BC-Fe_(3)O_(4)材料具有较好的可回收性、无二次污染等优势;不同的铁改性方法导致了生物炭对主要污染物的吸附效果和机制�Initial rainfall surface runoff in residential areas is one of the important sources of urban non-point source pollution.The main pollutants include total nitrogen(TN),total phosphorus(TP),nitrate nitrogen(NO;-N),etc.,which can cause eutrophication of receiving water body,thus decreasing the aquatic quality and urban landscape in urban residential areas.Taking a typical urban residential area(Wuxi city in Jiangsu Province)as the study area,this paper investigates the pollutant concentration and pollution load of the initial rainfall runoff on different underlying surfaces by field monitoring.The paper also studies the characterization methods,adsorption kinetics and thermodynamics of raw biochar(BC),modified iron biochar(BC-Fe)and magnetic carbon(BC-Fe_(3)O_(4)).We also explore the adsorption and reduction performance of different biochar materials on the main pollutants in the initial rainfall runoff.The results are as follows:the main pollutants in the initial rainfall runoff of typical residential areas are nitrogen and phosphorus,and the annual pollution loads of TN and TP per unit area of traffic avenue,roads in residential area,roof,park green space and parking lot are 4.17 kg/(hm^(2)·a),2.82 kg/(hm^(2)·a),0.88 kg/(hm^(2)·a),0.69 kg/(hm^(2)·a),0.62 kg/(hm^(2)·a)and 1.78 kg/(hm^(2)·a),0.56 kg/(hm^(2)·a),0.22 kg/(hm^(2)·a),0.06 kg/(hm^(2)·a),0.18 kg/(hm^(2)·a),respectively.According to the estimated pollution load per unit area,the pollution load per unit area generated by the runoff of traffic avenue is the highest,but the roads in residential area are 4.76 times of traffic avenue,so the total pollution load from the road flow in residential area is the highest.The adsorption effect of modified BC-Fe is the best adsorbent among the several biochar materials,and magnetic modified iron biochar can realize the secondary recovery of adsorbent.The adsorption capacity of NO_(3)^(-)-N and PO_(4)^(3-) is the highest under weak acid condition,and pseudo first order kinetic equation and Freundlich thermodyna

关 键 词：城市居民集中区 初期降雨地表径流 氮磷 污染负荷 改性生物炭 

分 类 号：X522[环境科学与工程—环境工程]