西溪湿地底泥重金属竖向分布规律

浙江大学学报(农业与生命科学版) 36(5):578~584,2010

Journal of Zhejiang University(Ag r ic &Life Sci )

文章编号:1008 9209(2010)05 0578 07DOI:10.3785/j.issn.1008 9209.2010.05.016西溪湿地底泥重金属竖向分布规律

陈如海1,詹良通1,陈云敏1,胡洪志2

(1.浙江大学建筑工程学院软弱土与环境土工教育部重点实验室,浙江杭州310058; 2.杭州市林水局,浙江杭州310014)

摘 要:利用特制的底泥取样器从杭州西溪湿地钻取通长的底泥试样,对不同深度底泥中重金属Cu、Pb、Zn进行测试,并分析重金属在表层底泥、底泥孔隙水及上覆水中的含量及相关性,用地累积指数法对底泥的污染程度进行评价.结果表明:该湿地0 6m深度内的底泥为轻度-中度污染,埋深大于0 6m的底泥没有被污染或者污染程度较轻;重金属在表层底泥孔隙水中的含量显著大于其在上覆水中的含量,由于浓度梯度,底泥孔隙水中的重金属会释放到上覆水中,因此如只实施换水处理难以根除水体污染问题,疏浚受污染的底泥是更有效的治理措施.根据测试结果,0 6m深度可作为湿地底泥疏浚的参考依据.

关 键 词:底泥;重金属;水质;孔隙水;湿地

中图分类号:X52 文献标志码:A

CHEN Ru hai1,ZH AN Liang tong1,CHEN Yun min1,HU H ong zhi2(1.M inistr y of Education Key L aboratory of Sof t Soils and Geoenvironmental Engineering,College of Civ il Engineering and A rchitectur e,

Zhej iang Univer sity,H angz hou310058,China; 2.H angz hou Municip al Bureau of For estry&W ater Resources,H angz hou310014,China)

Vertical distributions of heavy metals in bottom sediment in Xi xi national wetland.Jo urnal of Z hejiang U niv ersity(A g ric &L ife Sci ),2010,36(5):578 584

Abstract:A special sampler was made to dr ill o ut long and integ rated sediment samples fr om Xi x i natio nal wetland of Z hejiang P rov ince,and the contents of Cu,Pb and Zn in the sediments at differ ent depths w ere test ed to evaluate pollutio n deg r ee of the heav y metals,as well as to det ermine their distr ibutio n alo ng depth in the wetland using the method of geo accumulatio n index.T he t ests and evaluation r esults show ed that the sediments w ere moderately po lluted w ithin0 6m below the riv er bed,

and not polluted at the depth deeper than0 6m.T he concentr atio n of heavy metals in the shallo w

sediments w as fo und to be higher than t hat in po re w ater,w hich w as in turn much mo re than that in t he abov e w ater.H eav y metals in po re w ater of sediment s co uld be released into the above w ater due to t he concentr atio n g radient,indicating that the water quality in the w etland could no t be co mpletely recover ed o nly by r eplacing the polluted w ater w ith clean wat er,but needed to dr edg e the co nt aminat ed sediments in the wet land.T he top0 6m sediment should be dr edg ed fr om an eco no mic po int of v iew.

Key words:botto m sediment;heavy metals;w ater qualit y;po re wat er;w etlands

收稿日期:2009 11 25

基金项目:国家自然科学基金重点资助项目(50538080);杭州市水利规划设计研究院委托项目.

作者简介:陈如海(1976 ),男,江苏盐城人,博士研究生,从事环境岩土工程研究.E mail:crh76@.

通信作者:詹良通,男,教授,博士生导师,从事非饱和土力学、环境岩土工程及边坡工程研究.T el:0571 ********;E mail: z hanlt@.