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1.
太湖梅梁湾沉积物-水界面氮迁移特征初步研究   总被引:36,自引:7,他引:29  
用乙炔为抑制剂,气相色谱法测定了1997年夏季太湖梅梁湾口沉积物-水界面的反硝化率和N2O的自然排放率,太湖梅梁湾沉积物的反硝化率为1.4-5.6μmolN2/(m^2.h),N2O的复原斐和率为0.08-0.66μmolN2/(m^2.h),探讨了沉积物-水界面NO^-3的交换动态。指出沉积物内硝化-反硝化作用是太湖湖泊生态系统氮循环过程中一个重要的环节。在湖泊水土界面氮交换中,沉积物是具有吸收  相似文献   

2.
商景阁  张路  张波  范成新 《湖泊科学》2010,22(5):708-713
以中国长足摇蚊(Tanypus chinensis)幼虫对沉积物的生物扰动过程为研究对象,运用稳定同位素示踪及同位素配对技术,深入探讨长足摇蚊幼虫扰动对太湖梅梁湾沉积物硝酸盐界面迁移、溶解氧侵蚀深度及沉积物反硝化速率及两种不同反硝化过程(非耦合反硝化(DW)和耦合反硝化(DN))的影响.摇蚊幼虫扰动后,添加15N两种处理沉积物氧气消耗速率由355.49±131.49μmol/(m2.h)变化为546.39±261.41μmol/(m2.h),而未添加15N两种处理由313.57±61.63μmol/(m2.h)变化为554.17±184.36μmol/(m2.h),硝酸盐界面迁移结果表明:扰动显著加强了水体硝酸盐向沉积物迁移的速率,加强沉积物作为上覆水中NO3-N汇的作用,摇蚊幼虫扰动组的硝酸盐迁移速率从-33.75±29.25μmol/(m2.h)提高到-210.14±117.25μmol/(m2.h).同位素添加实验发现,摇蚊幼虫底栖扰动能显著提高沉积物总反硝化速率,与对照组相比,总反硝化速率从31.83±8.79μmol/(m2.h)上升到228.98±54.09μmol/(m2.h),增加了约6倍左右.利用同位素配对法计算对两种不同反硝化过程进行区分,发现非耦合反硝化速率从15.78±8.51μmol/(m2.h)上升到182.96±45.22μmol/(m2.h),耦合反硝化速率从16.04±5.63μmol/(m2.h)增加到46.01±8.97μmol/(m2.h),预示着底栖生物扰动能同时增加耦合和非耦合两种反硝化过程,而非耦合反硝化过程的增加强度远大于耦合反硝化.  相似文献   

3.
太湖梅梁湾水土界面反硝化和厌氧氨氧化   总被引:18,自引:3,他引:15       下载免费PDF全文
运用无扰动芯样实验室内流动培养、稳定同位素示踪、同位紊气态产物测定及同位素配对技术,对太湖梅梁湾北部到南部的4个梯度样点的水土界面反硝化和厌氧氨氧化速率进行研究.结果表明,梅梁湾内及湾外开敞湖区4个样点的水土界面反硝化脱氮速率为(46.36±13.26)-(16.34±22,74)μmol/(m~2·h),厌氧氨氧化脱氮速率为(7.50±2.21)-(2.05±2.90)~mol/(m~2.b).梅梁湾北部河口区水土界面总脱氮能力明显高于梅梁湾南部及开敞湖区.通过对脱氮过程的进一步研究发现.北部脱氮过程主要以上覆水硝酸盐为底物的非耦合反硝化过程(D_w)为优势过程,而梅梁湾外开敞湖区则以沉积物硝化过程耦合控制的反硝化(D_n)为主.影响D_n、D_w在反硝化中比重的主要因素是沉积物溶氧侵蚀深度和上覆水NO_3~-.浓度的差异;梅梁湾厌氧氨氧化脱氮比例占总脱氮比例为12%-14%,湾外开敞湖区则占11%,影响其比例差异的主要因子是反硝化强度的大小及其反硝化中间产物--亚硝酸盐含量的差异.  相似文献   

4.
长江口崇明东滩沉积物反硝化作用研究   总被引:15,自引:0,他引:15  
选择长江河口崇明岛东部潮滩为典型研究区域, 从2003年7月到2004年7月在崇明东滩(CM)进行了隔月采样, 研究表明水体自身N2O产生速率很低, 沉积物是上覆水体N2O的来源, 沉积物中N2O产生速率在-0.08~1.74 mmolN·m-2·h-1之间, 夏季是N2O产生速率较高的季节. 不同潮滩部位N2O产生速率的差异, 以及N2O产生速率与反硝化速率、温度、溶解氧的相关关系表明中潮滩(CM-2)沉积物反硝化作用可能是N2O的主要产生源, 低潮滩(CM-3)沉积物中N2O来源于氮素循环的多个反应过程. 冬季和夏季是潮滩沉积物反硝化作用较强的季节, 晚秋(11月)、初春(3月)反硝化速率相对较低, 潮滩沉积物反硝化速率季节变化较大(1.12~34.09 mmolN·m-2·h-1). 温度、溶解氧以及二者的共同作用是影响潮滩沉积物反硝化作用进行的显著因素.  相似文献   

5.
水塘是连接上游集水坡地和下游水体的重要水文通道,也是氮素发生生物地球反应的重要场所.作为氮素高效去除的首要机制,水塘的反硝化脱氮潜力及其影响因素亟待揭示.本研究选择太湖上游丘陵区天目湖流域4类(茶园塘、村塘、养殖塘、林塘)共14个典型水塘为研究区,分别监测了其夏、秋季水质和沉积物变化特征,并利用膜进样质谱法(MIMS)直接测定水塘水体中溶存的反硝化产物N2浓度.结果发现,14个水塘上覆水中N2过饱和浓度在1.36~28.35 μmol/L之间,平均值为(8.23±6.04)μmol/L,夏季和秋季N2过饱和浓度分别为(8.81±4.08)和(7.64±7.46)μmol/L,夏季高于秋季,不同类型水塘N2过饱和浓度大小顺序为:茶园塘>村塘>养殖塘>林塘;结合水气交换通量模型估算了反硝化潜力,14个水塘的反硝化速率均值为(4.75±3.27) mmol/(m2·d),反硝化速率大小顺序为:茶园塘>村塘>养殖塘>林塘.相关分析结果表明,反硝化作用与水体中硝态氮浓度呈显著正相关,与溶解氧浓度呈显著负相关;反硝化作用同样与沉积物中硝态氮含量呈显著正相关,与容重呈负相关,说明水塘反硝化作用同时受上覆水中硝态氮、溶解氧以及沉积物容重等理化性质共同调节.进一步通过与传统的反硝化测算方法对比验证,发现采用膜进样质谱法并结合水气交换通量模型来估算水体反硝化潜力具有可行性,同时操作简便、所需样品少、测定速度快,适用于淹水环境反硝化作用的测定.  相似文献   

6.
姜星宇  姚晓龙  徐会显  张路 《湖泊科学》2016,28(6):1283-1292
反硝化(Denitrification,DNF)和硝酸盐异化还原为氨(Dissimilatory Nitrate Reduction to Ammonium,DNRA)是硝酸盐异养还原的2个主要途径.反硝化被认为是彻底去除水体氮负荷的主要过程;而硝酸盐异化还原为氨则将水体中的硝态氮转化为氨氮.2个过程均以硝酸盐为电子受体,并存在相互竞争关系.这2个过程的研究对理解湿地氮转化以及指导湿地氮污染修复具有重要意义.运用无扰动沉积物柱样流动培养、15NO-3-N同位素示踪实验,并采用氨氧化-膜接口质谱仪联用(OX/MIMS)测定氨氮同位素产物的方法,对鄱阳湖碟形湖湿地、巢湖重污染河流湿地、巢湖重污染湖泊湿地3种类型湿地沉积物-水界面的硝酸盐异养还原过程进行研究,结果表明存在显著差异.3种类型湿地DNF速率的范围为(6.36±2.57)~(99.98±14.05)μmol/(m2·h),DNRA速率的范围为(0.51±0.45)~(79.82±6.08)μmol/(m2·h).在3种类型湿地中,随着氮污染程度加重,DNF和DNRA速率均显著增加,且DNRA过程在总的硝态氮异养还原中所占的比重不断增大,说明较高的硝酸盐负荷、较高的沉积物有机质含量更有利于DNRA过程的竞争.而对反硝化方式的进一步研究发现,巢湖重污染河流、湖泊湿地主要以非耦合反硝化为主导过程,而鄱阳湖碟形湖湿地则更倾向于以硝化过程耦合控制的反硝化为主.  相似文献   

7.
王君波  朱立平 《湖泊科学》2008,20(6):715-722
从沉积物磷的化学形态特征、沉积物-水界面的环境条件和水库的水文参数等角度探讨了山仔水库沉积物磷对上覆水体的磷浓度贡献,并从沉积物间隙水与水体垂向溶解性磷的浓度梯度估算对水体磷浓度的贡献大小.结果表明:山仔水库沉积物具有大的释放磷的潜力,沉积物间隙水和水体之间存在着明显的溶解性磷的浓度梯度,沉积物的溶解性磷释放通量在0.0420—0.167μg/(cm^2·d))之间,沉积物磷对水体营养贡献大小在0.7%-6%之间,其中秋冬季节沉积物磷对水体的贡献大于春夏季节,当外源减少时,沉积物磷负荷在一定时间内将成为水库营养状态的重要贡献因子。  相似文献   

8.
高寒草甸是青藏高原广泛分布的植被类型,面积约1.2×106km2,位于青藏高原腹地的西藏当雄县即是典型分布区之一.以2003年生长季在当雄草原站用涡度相关法连续观测的CO2通量数据为基础,分析了净生态系统二氧化碳交换量(NEE)与光合有效辐射(PAR)之间的关系,及其表观量子产额(α)和表观最大光合速率(Pmax)在生长季中的变化特征.结果表明:白天的NEE与PAR之间符合很好的直角双曲线关系;α随生长季依次为草盛期>草盛初期>种子成熟期>枯黄期,最大为0.0244μmolCO2·μmol?1PAR,最小仅0.0098μmolCO2·μmol?1PAR;Pmax在草盛初期、草盛期、种子成熟期变化不大,平均0.433mgCO2·m?2·s?1(9.829μmolCO2·m?2·s?1),在枯黄期仅0.35mgCO2·m?2·s?1(7.945μmolCO2·m?2·s?1).青藏高原高寒草甸的α值与世界上其他的草原生态系统相比,明显偏小.  相似文献   

9.
太湖梅梁湾南部水体有机污染物降解表观动力学初步分析   总被引:2,自引:1,他引:1  
有机污染是太湖水质恶化的重要原因之一.本文在20℃和30℃恒温振荡条件下,应用化学反应动力学原理定量模拟和研究了太湖梅梁湾南部附近水体中,有机污染指标COD(Mn)降解的一级反应过程.应用Arrenius系列公式,分别得到20℃和30℃下的降解速率常数(k20=0.01856d(-1),k30=0.0364d(-1))、表观活化能(Eu=4.9×104J)及指前因子A.提出太湖梅梁湾南部水体COD衰减表达式为:Ct=C0·exp[-1.49×10e7(-4.9×104/RT)t].  相似文献   

10.
反硝化作用是将氮素从湖泊中彻底去除的重要途径之一,对于减轻湖泊富营养化具有重要意义。为了探究太湖沉水植物附着生物的生物量、潜在反硝化速率变化规律及其与环境因素的关系,在沉水植物生长盛期(7月),以太湖沉水植物主要分布区域东部湖湾作为采样区域,研究了太湖常见的3种沉水植物上附着生物的生物量,并利用乙炔抑制法测定沉水植物上附着生物的潜在反硝化速率,分析了太湖沉水植物附着生物的生物量及其潜在反硝化速率的主要影响因素。结果表明,太湖常见的3种沉水植物单位体表面积附着生物的生物量(AFDM)在0.037~0.789 mg/m2之间,均值为(0.389±0.261) mg/m2,沉水植物上附着生物的生物量存在空间差异,最大值出现在贡湖湾G1采样点((0.794±0.007) mg/m2),最小值出现在胥口湾X1采样点((0.041±0.005) mg/m2)。太湖沉水植物单位体表面积附着生物的潜在反硝化速率在3.09~58.80 μmol/(m2·h)之间,均值为(24.75±5.96)μmol/(m2·h)。太湖沉水植物附着生物的潜在反硝化速率存在空间差异,其中最大值出现在贡湖湾G1采样点((58.80±20.20) μmol/(m2·h)),最小值出现在胥口湾X1采样点((3.09±1.79) μmol/(m2·h))。相同条件下,沉水植物附着生物的生物量及潜在反硝化速率因植物种类的不同而存在差异,狐尾藻(Myriophyllum spicatum)上的附着生物的生物量及潜在反硝化速率显著高于苦草(Vallisneria natans)。相关性分析结果表明,沉水植物上附着生物的生物量与水体氮磷浓度相关。沉水植物附着生物的潜在反硝化速率与附着藻类的生物量、水体溶解有机碳及pH存在显著相关关系,这3种因子可以解释81.2%的沉水植物附着生物潜在反硝化速率变化,本研究结果可为进一步研究浅水湖泊脱氮过程及富营养化治理提供一定的理论依据。  相似文献   

11.
It have been measured the denitrification rates (DR) of sediment in Saginaw Bay, Lake Huron, by N2 production method. Triplicate samples of sediment core were collected at two GLERL long-term monitoring sites of the Bay in July and August of 1995. The DR are 48.81 -24.99 and 32.81-40.51 micromol N2 -2h-1 in the Inner and Outer regions of Saginaw Bay, respectively.The characters of DR in Saginaw Bay were studied also in this paper. The DR were influenced by the interactions between the Saginaw River as a main pollution source and the Lake Huron as a reservoir of high quality water. The impacts of zebra mussels (Dreissena Polymorpha) on denitrification in Saginaw Bay, Lake Huron, were discussed, Significant differences in NH4+ exchange fluxes were detected in the inner and outer bays. The molar ratios of N2:TIN were similar at both sampling sites. Measured DR were positively correlated to O2 consumption rates in the headspace. Additionally, a negative correlation between NH4+ and NO3- concentrations in the overlying water was found.  相似文献   

12.
通过采集太湖西北部闾江口、八房港、月亮湾和竺山湾疏浚区与未疏浚对照区8个样点共32根沉积物柱状样于室内进行内源负荷模拟研究和沉积物基本性质分析发现,除闾江口疏浚区沉积物总磷和可交换态磷含量高于未疏浚区外,其余指标如烧失量、总氮、可交换态氮等均表现为未疏浚区沉积物高于疏浚区沉积物的特征,说明疏浚区沉积物营养盐的释放潜力低于未疏浚对照组.八房港、月亮湾以及竺山湾疏浚区沉积物铵态氮、正磷酸盐的潜在释放速率均比相应未疏浚对照区沉积物低,疏浚区沉积物铵态氮的潜在释放速率分别是未疏浚区的65.3%、88.8%和21.9%,正磷酸盐的潜在释放速率分别是未疏浚区的-26.6%、11.3%和50.2%.而闾江口疏浚区沉积物铵态氮和正磷酸盐的潜在释放速率却远高于未疏浚区(疏浚区分别为未疏浚区的2.6倍和6.4倍),这可能与闾江口水体呈现弱还原环境及沉积物中有机质含量高有关,另外也可能与闾江口沉积物污染物的赋存深度和疏浚工程的疏浚深度有关.  相似文献   

13.
Michigan basin regional ground water flow discharge to three Great Lakes   总被引:1,自引:1,他引:0  
Ground water discharge to the Great Lakes around the Lower Peninsula of Michigan is primarily from recharge in riparian basins and proximal upland areas that are especially important to the northern half of the Lake Michigan shoreline. A steady-state finite-difference model was developed to simulate ground water flow in four regional aquifers in Michigan's Lower Peninsula: the Glaciofluvial, Saginaw, Parma-Bayport, and Marshall aquifers interlayered with the Till/"red beds," Saginaw, and Michigan confining units, respectively. The model domain was laterally bound by a continuous specified-head boundary, formed from lakes Michigan, Huron, St. Clair, and Erie, with the St. Clair and Detroit River connecting channels. The model was developed to quantify regional ground water flow in the aquifer systems using independently determined recharge estimates. According to the flow model, local stream stages and discharges account for 95% of the overall model water budget; only 50% enters the lakes directly from the ground water system. Direct ground water discharge to the Great Lakes' shorelines was calculated at 36 m3/sec, accounting for 5% of the overall model water budget. Lowland areas contribute far less ground water discharge to the Great Lakes than upland areas. The model indicates that Saginaw Bay receives only approximately 1.13 m3/sec ground water; the southern half of the Lake Michigan shoreline receives only approximately 2.83 m3/sec. In contrast, the northern half of the Lake Michigan shoreline receives more than 17 m3/sec from upland areas.  相似文献   

14.
太湖草/藻型湖区沉积物-水界面环境特征差异   总被引:3,自引:0,他引:3  
在太湖草、藻型湖区进行冬、夏两季多点采样,分别对采样点的水环境特征、泥面以上5 cm上覆水中营养盐以及沉积物的含水量、中值粒径、有机碳、氮、磷、金属元素和溶解氧进行测定.结果表明:夏季藻型湖区表层水体pH高于中、底层,冬季草型湖区各层水体pH高于藻型;草型湖区水体浊度夏季低于藻型,冬季反之;藻型湖区上覆水中的硝态氮和磷酸根浓度显著高于草型;草型湖区沉积物中含水量冬季显著高于夏季;草型湖区沉积物中总有机碳显著高于藻型;Fe、Zn、Ca、Pb、Na和K等元素在草、藻型湖区间差异显著;沉积物中溶解氧表现为冬季深于夏季,藻型深于草型的规律.  相似文献   

15.
太湖浮游植物细胞裂解速率的酯酶活性法初步研究   总被引:1,自引:1,他引:0  
本研究从2009年8月至2010年10月,每月采集太湖3个不同富营养化湖区水样,运用酯酶活性法,测定了颗粒态酯酶、溶解性酯酶活性以及酯酶衰变周期,估算了太湖浮游植物细胞裂解速率.研究结果表明,太湖颗粒态酯酶活性为0.58~35.15 nmol FDA/(L.h),溶解性酯酶活性为0.55~7.59 nmol FDA/(L.h),酯酶衰变周期为7~75 h,细胞裂解速率为0.02~0.77 d-1,三个采样点细胞裂解速率没有显著差异.颗粒态酯酶活性与叶绿素a浓度之间具有显著的线性关系,说明运用酯酶活性法估算太湖浮游植物细胞裂解速率是可行.此外,叶绿素a浓度与温度变化趋势基本一致,梅梁湾和湖心叶绿素a浓度具有显著差异.贡湖湾叶绿素a浓度与细胞裂解速率之间具有显著的反比例关系,说明细胞裂解速率也是影响太湖藻类生物量的重要因素.  相似文献   

16.
肖启涛  胡正华  张弥  王伟  肖薇 《湖泊科学》2021,33(2):561-570
外源引水等水力调控措施常用于湖泊水环境综合整治中,作为人类施加到湖泊显著的外界活动,其对湖泊甲烷(CH4)扩散通量的影响鲜有报道.贡湖湾作为"引江济太"工程长江来水进入太湖的第一站,其CH4通量变化是对水力调控的最好响应.基于2011年11月至2013年8月逐月的野外观测表明,贡湖湾平均CH4扩散排放量为0.073 mmol/(m2·d),显著高于参考水域(湖心区) CH4排放量(均值:0.017 mmol/(m2·d)).贡湖湾不同站点间CH4通量也表现出显著差异,但湖心区域无此现象.贡湖湾和湖心2个区域的CH4扩散通量均有明显的时间变化,且与水温呈显著正相关.但因受到外源来水的影响,贡湖湾CH4通量时间变化的温度依赖性相对较低.总体上外源引水显著提高了湖体CH4排放量,考虑到湖泊CH4通量受内部因子和外部因子的综合协调影响,其潜在的控制机制还需要进一步探讨.  相似文献   

17.
Results of Seepage Meter and Mini-Piezometer Study, Lake Mead, Nevada   总被引:2,自引:1,他引:2  
The seepage meter and the mini-piezometer were utilized in an attempt to evaluate ground-water reservoir interactions over a 12-month period at Echo Bay in Lake Mead. In conjunction with these techniques three standard piezometers, refraction seismic data, and water chemistry data were utilized to interpret seepage device results. During a four-month period, from December 1979 to March 1980, an 8 ft (2.5 m) rise in reservoir stage, the reservoir contributed water to Echo Wash bank storage at rates of up to 0.29 gpd/ft2 (12 lpd/m2). Ground-water discharge occurred for the remainder of the project, during a stage decline from April 1980 to May 1980, a rise in June 1980, and leveling off and slight decline for the remainder of the year, July 1980 to December 1980. The maximum seepage meter ground-water discharge rate of 3.0 gpd/ft2 (122 lpd/m2) was recorded in December 1980. Seepage meter water chemistry data for June were similar to Lake Mead water chemistry and were interpreted to be previously recharged Lake Mead water. September water chemistry data showed two possible components of ground-water discharge, a high SpC calcium sulfate Echo Wash ground water and a lower SpC Lake Mead recharged bank storage water. December ground-water chemistry data showed discharge to be a high SpC calcium sulfate water similar to Echo Wash ground-water quality which was apparently unaffected by Lake Mead inflow. Mini-piezometer data were collected at each seepage meter site. However, these data usually did not provide correlative results with seepage meter data probably because of suspended sediment in the piezometer water column and plugging of the perforated tip. Seepage meters were successfully utilized to characterize reservoir ground-water interaction in Echo Bay.  相似文献   

18.
An examination of the lithology, paleomagnetic and Mossbauer Effect Spectroscopy (MES) log data and 14C determinations of cores taken from three small basins located in western Lake Erie, in conjunction with data obtained from earlier studies, has been used to re-evaluate the postglacial history of the area. After the re-advance of the Laurentide Ice Sheet into the Huron basin and the eastern part of the Erie basin during the Port Huron stadial about 13,000 yrs B.P., lacustrine clay was deposited across much of the western Erie basin in a lake ponded against the glacial ice front to the east. However, by 12,000 yrs B.P. as the ice front retreated, the waters from the Huron basin bypassed Lake Erie, first by the Kirkfield outlet to Lake Ontario, and later by the Fossmill and North Bay outlets to the Ottawa River. This resulted in the draining of water from most of the western Erie basin. Extensive swamps choked with plants formed in the small basin areas, and the surrounding low-lying former lake bottom was subjected to subaerial weathering. It would appear that by about 9,500 yrs B.P. there was an increase in surface run off into these basins and the swamps evolved into shallow, relatively warm-water lakes in which calcareous-rich clay was deposited. Isostatic rebound of the northeastern outlets of the Huron basin led to a gradual tilting of the basin and a progressive migration of the southern shoreline of Lake Huron (Lake Stanley phase) to the southwest. By about 5000 yrs B.P. the water level in the southern Huron basin had been raised sufficiently to re-open the Port Huron outlet into the Erie basin. This resulted in a substantial rise in the lake level in the Erie basin, terminated the deposition of calcareous-rich clay in the small basins, and led to the deposition of normal lacustrine sediments in the modern phase of Lake Erie.  相似文献   

19.
A combination of field measurements, modelling and laboratory experiments was used to evaluate the potential impact of sediment resuspension on phosphorus (P) dynamics. The study was carried out in two adjacent shallow coastal lakes (Lake Honda and Lake Nueva) which, due to their geographic proximity (only 200 m apart), are subject to equal meteorological forcing and represent ideal systems to study how morphometry and sediment properties relate to wind events. The focusing factors (a measure of the fluxes of sediment into the water column through resuspension) estimated by comparing settling fluxes measured in surface sediment traps with those measured in bottom traps, were significantly larger (approximately 34% larger) in Lake Honda (LH; 1.18) than in Lake Nueva (LN; 0.88). Our model estimates of resuspension fluxes (E) were also ca. 40% larger in LH than in LN, in agreement with the observed focusing factors. The larger resuspension fluxes encountered in LH, in comparison with LN, can mainly be explained by differences in lake morphometry. Still, they could arise from differences in grain size distribution or in benthic algae concentration encountered in the lake sediments. By means of adsorption experiments in the laboratory, we show that resuspension events will have different effects on P-dynamics in LH and LN. While the resuspended material from LH tends to adsorb phosphate (PO4 3−), removing it from the water column, in LN the resuspended sediments tend to increase the availability of PO4 3− in solution. These differences arise from (1) higher concentrations of PO4 3− in water in LH compared to LN; and (2) larger PO4 3−adsorption capacity of the LH sediments as a result of the more abundant iron oxyhydroxides and clay.  相似文献   

20.
湖泊水华存在复杂的生消过程,然而目前较多研究聚焦在水华持续阶段对湖泊生态系统的影响,却较少关注水华生消过程对湖泊水体和沉积物理化性质的影响.以巢湖为对象,根据历史资料确定水华区和非水华区,在相同位点分别于水华形成前期、形成期、持续期和消亡期采集水体和沉积物样品,分析水华生消过程对湖泊水体和沉积物理化指标及营养盐的影响.结果表明,巢湖研究区域水华形成期为5月中旬至6月中旬,持续期为6月中旬至9月上旬,之后进入水华消亡期.水体透明度、p H值和溶解氧在水华区与非水华区大部分时间存在显著差异,且随水华生消过程呈现不同的变化趋势,但水温、氧化还原电位和电导率在水华区和非水华区无显著差异,并随水华生消过程呈现相同的变化趋势.非水华区水体和沉积物中各形态氮、磷浓度明显低于水华区,且随时间变化幅度相对较小.在水华区,水体氮、磷浓度(总溶解性氮、硝态氮、氨氮、总氮、总溶解性磷、磷酸盐)在水华形成期和水华持续前期呈下降趋势,但在水华持续后期和水华消亡期呈增加趋势;沉积物氮、磷浓度(总氮、总磷)和总有机质含量显著高于非水华区,三者在水华区和非水华区随水华生消过程呈现不同的变化趋势.研究表明,水华生消过程对湖泊营养盐和水体及沉积物性质有不同的影响,这对湖泊富营养化治理和水华防治具有重要意义.  相似文献   

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