疏浚底泥脱水固结处理后氮磷营养盐释放特征研究  

Study on the release characteristics of nitrogen and phosphorus nutrients fromdredging sediment after dewatering and consolidation treatment

作　　者：李运奔 张建华[2] 殷鹏[2] 范成新[1] 申秋实[1,3] LI Yunben;ZHANG Jianhua;YIN Peng;FAN Chengxin;SHEN Qiushi(Key Laboratory of Lakes and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China;Jiangsu Water Resources Service Center,Nanjing 210029,China;Sino-Africa Joint Research Center,Chinese Academy of Sciences,Wuhan 430074,China)

机构地区：[1]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,江苏南京210008 [2]江苏省水资源服务中心,江苏南京210029 [3]中国科学院中非联合研究中心,湖北武汉430074

出　　处：《江苏水利》2020年第12期9-16,共8页Jiangsu Water Resources

基　　金：江苏省水利科技项目(2018004);国家自然科学基金项目(41877488);中国科学院海外科教基地建设项目(SAJC201609)。

摘　　要：以太湖西沿岸区、梅梁湾、东太湖底泥为对象,采用室内模拟的方法,在静态和动力扰动2种不同情景下,研究了疏浚底泥脱水固结处理后内源氮磷营养盐释放特征。结果表明:各研究区域底泥氮磷营养盐释放能力较强,TN、TP释放速率分别在7.26~29.65 mg/(m 2·d)和-0.37~1.42 mg/(m 2·d)之间。脱水固结处理后,疏浚底泥内源TN、TP释放能力明显降低,其TN、TP静态释放速率分别释放为3.36~22.98 mg/(m 2·d)和-0.37^-0.07 mg/(m 2·d),底泥内源氮磷释放能力尤其是TP释放能力明显减小。在动力扰动的情况下,脱水固结处理清淤污泥TN释放速率为6.31~30.96 mg/(m 2·d),较原状底泥降低85%以上,TP释放速率为-0.23~0.37 mg/(m 2·d),较原状底泥降低98%以上。脱水固结处理后底泥含水率、孔隙度均大幅减小,抗扰动能力增强,内源氮磷营养盐释放能力减弱,内源氮磷二次污染风险明显降低。Taking the sediments of west coast of Taihu Lake,Meiliang Bay and East Taihu Lake as research objects,the release characteristics of endogenous nitrogen and phosphorus nutrients from dredged sediments after dewatering and consolidation were studied by using the method of indoor simulation under two different scenarios of static and dynamic disturbance.The results showed that the release capacity of nitrogen and phosphorus nutrients from sediments in each study area was strong,and the release rates of TN and TP ranged 7.26~29.65 mg/(m 2·d)and-0.37~1.42 mg/(m 2·d),respectively.After dewatering and consolidation treatment,the release capacity of endogenous TN and TP of dredged sediments was significantly reduced,and the static release rates of TN and TP were 3.36~22.98 mg/(m 2·d),-0.37^-0.07 mg/(m 2 d).The release capacity of endogenous nitrogen and phosphorus in sediments,especially the release intensity of TP,was significantly reduced.With the dynamic disturbance,the release rates of TN and TP of the dredged sediments after dehydrated solidification treatment were 6.31~30.96 mg/(m 2·d)and-0.23~0.37 mg/(m 2·d).Compared with the dynamic release rates of the in-situ sediments,the dynamic release rates of TN and TP of the dredged sediments after dehydrated solidification treatment reduced more than 85%and 96%,respectively.After the dehydrated solidification treatment,the moisture content,porosity,fluidity and resuspension ability of the dredged sediments were reduced and the release ability of TN and TP decreased significantly,which weakened the risk of secondary pollution from sediment internal nutrients release largely.

关 键 词：疏浚 底泥 固结 氮磷营养盐 太湖 

分 类 号：X524[环境科学与工程—环境工程]