Sediment cores were collected in different areas with different ecological states in Lake Taihu to observe vertical variation in physicochemical characteristics of sediments and porewater inorganic nitrogen.The three areas were Xukou Bay dominated by macrophytes,Central Lake with strong wave and less algal bloom,Meiliang Bay with severe algal bloom.The results showed that water content,organic matter,and TN decreased with increasing sediment depth in the three sampling sites,with the highest values observed in Meiliang Bay while the lowest values in Central Lake.Meanwhile,dissolved oxygen within sediments decreased with increasing sediment depth,and the highest concentration was found in Xukou Bay and the lowest in Meiliang Bay.Porewater ammonium concentration increased dramatically downward in the sediments,in contrast to nitrate and nitrite concentrations.A comparison of inorganic nitrogen concentration from within top 5-cm sedimentary porewater and the overlying water suggested that release risk of nitrate and nitrite was low in all three areas;both Xukou Bay and Meiliang Bay had a relatively high risk for ammonium release into overlying water,while the risk was low in Central Lake.
[1] Von Gunten H.R.,Sturm M.,Moser R.N.200-year record of metals in lake sediments and nature background concentrations[J].Environmental Science and Technology,1997,31:2193-2197.
[2] 秦伯强,胡维平,陈伟民.太湖水环境演化过程与机理[M].北京:科学出版社,2004.162-170.
[3] 李江,金相灿,姜霞,刘利军.太湖不同营养水平湖区沉积物理化性质和磷的垂向变化[J].环境科学研究,2007,20(4):64-69.
[4] Qu Wenchuan,Dickman M,Wang Sumin.Multivariate analysis of heavy metal and nutrient concentrations in sediments of Taihu Lake,China[J].Hydrobiologia,2001,450:83-89.
[5] Rysgaard S,Glud R N,Risgaard P N,Dalsgaard T.Denitrification and anammox activity in Arctic marine sediments[J].Limnology and Oceanography,2004,49(5):1493-1502.
[6] Soto-Jimenez M F,Paez-Osuna F,Bojorquez-Leyva H.Nutrient cycling at the sediment-water interface and in sediments at Chiricahueto marsh:a subtropical ecosystem associated with agricultural land uses[J].Water Research,2003,37:719-728.
[7] Serryua C,Edelstein M,Pollingher U,Serruya S.Lake Kinneret sediments:nutrients composition of the pore water and mud water exchanges[J].Limnology and oceanography,1974,19(3):489-508.
[8] 赵兴青,杨柳燕,于振洋,樊启慧,詹忠,肖元庚,尹大强,秦伯强.太湖沉积物理化性质及营养盐的时空变化[J].湖泊科学,2007,9(6):698-704.
[9] 范成新,杨龙元,张路.太湖底泥及其间隙水中氮磷垂直分布及相互关系分析[J].湖泊科学,2000,12(4):359-366.
[10] 李英杰,胡小贞,年跃刚,沈炳刚,张黎.草型和藻型湖泊间隙水营养盐特征的比较研究[J].水生态学杂志,200992(5):25-29.
[11] Reilly J F,Horne A J,Miller C D.Nitrate removal from a drinking water supply with large flee-surface constructed wetlands prior to groundwater recharge[J].Ecological Engineering,2000,14:33-47.
[12] 朱爱美,叶思源,卢文喜.鳌山湾沉积物间隙水营养盐的含量极其分布[J].江苏环境科技,2006,19(2):20-22.
[13] 金相灿,姜霞,徐玉慧,王琦.太湖东北部沉积物可溶性氮、磷的季节性变化[J].中国环境科学,2006926(4):409-413.
[14] Graca B,Witek Z,Burska D,Biafcowska I,Lukawska-Matuszewska K,Bolatek J.Pore-water phosphate and ammonia below the permanent halocline south-eastern Baltic Sea and their benthic fluxes under anoxic conditions[J].Journal of Marine System,2006,63:141-154.
[15] 张兴正,陈振楼,邓焕广,许世远.长江口北支潮滩沉积物-水界面无机氮的交换通量及季节变化[J].重庆环境科学,2003,2S(9):31-35.
[16] 范成新,相崎守弘.好氧和厌氮条件对霞浦湖沉积物-水界面氮磷交换的影响[J].湖泊科学,1997,9(4):337-342.
[17] 张水元,刘瑞秋,黎道丰.保安湖沉积物和间隙水中氮和磷的浓度及其分布[J].水生生物学报,2000,24(5):434-438.
[18] 胡俊,刘永定,刘剑彤.滇池沉积物间隙水中氮、磷形态及相关性的研究[J].环境科学学报,2005,25(10):1391-1396.
