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1.
Matrix-bound phosphine (MBP) has been measured in sediment from two cores in Lake Illawarra on the south east coast of Australia. The sediments were also dated in the upper layers. MBP concentrations found range from 142 to 1813 ng kg−1, dw (dry weight of sediment) with some values being amongst the highest ever measured. Values of MBP in deeper sediments were higher than for near surface samples, but the patterns with depth were not consistent. Strong correlations were noted between MBP and organic phosphorus (OP, r > 0.8) and with total phosphorus (TP, r > 0.7), but only moderate correlations were found with organic carbon (OC, r > 0.5). No correlations were found between MBP concentrations and the age of the sediments. It was confirmed that high MBP concentrations are indicative of a phosphorus rich environment. The results tend to support the premise that MBP is generated by microbial attack on OP under anaerobic conditions.  相似文献   

2.
Matrix bound phosphine (MBP), a kind of chemically reduced phosphorus, has received limited attention in prevailing modeling of the phosphorus biogeochemical cycle. MBP has been found to occur in marine sediments. MBP in the sediments of the Yellow Sea and its coastal areas was measured by gas chromatography from 2004 to 2007. MBP levels in surface sediments were 0.19–38.24 ng kg−1 in the shelf of the Yellow Sea, 0.34–17.15 ng kg−1 in the Jiaozhou Bay, 2.11–71.79 ng kg−1 in the Sanggou Bay and 0.28–319.32 ng kg−1 in the rivers around the Jiaozhou Bay. High levels of MBP occurred in the northern and middle areas of the Yellow Sea. Obvious seasonal variation of MBP was observed in surface sediments of the Sanggou Bay, with the highest MBP level occurring in summer and the lowest in winter. MBP in surface sediments of the inner Jiaozhou Bay was higher than those in the outer region. MBP levels increased with depth in the top 5–10 cm sediments of the Jiaozhou Bay and on the intertidal flats. Environmental factors such as type of sediments, temperature, organic matter and human activity were found to affect the concentrations and distribution of MBP in marine sediments.  相似文献   

3.
The concentrations, compositional profiles, and potential ecological risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in sediments of the Daliao River Estuary were investigated. Total concentrations of PCDD/Fs, PCBs, and PCNs were in the range of 11.3-133.2 ng/kg dry weight (dw), 1 971-37 632 ng/kg dw and 33.1-284.4 ng/kg dw, respectively. The total TEQ values varied from 0.37 to 4.08 ng/kg dw, with the dominant contributions by PCDD/Fs, then by PCBs and PCNs. The spatial distributions of PCDD/Fs, PCBs and PCNs in the river estuary were much related to hydrodynamic conditions. The risk of contamination to the deeper sea was increased in the flood seasons. Moreover, our data confirmed that both organic matter in sediments and molecular properties of dioxin-like compounds were the factors which strongly influenced the partition behavior of these dioxin-like compounds between sediments and water phase in the estuarine zone.  相似文献   

4.
Phosphorus (P) concentrations in sediments and in surface and interstitial water from three gravel bars in a large river (Garonne River, southern France) were measured daily, downstream of a wastewater treatment plant for a city of 740 000 inhabitants (Toulouse). Measurements were made of vertical hydraulic gradient (VHG), total dissolved phosphorus (TDP), soluble reactive phosphorus (SRP) and total phosphorus (TP) in water and of three extractable forms of phosphorus (water extractable, NaOH extractable and H2SO4 extractable) in hyporheic sediments from the gravel bars. Dissolved phosphorus was the major contributor to TP (74–79%) in both interstitial and surface waters on all sampling dates, and in most cases surface water P concentrations were significantly higher than interstitial concentrations. Hyporheic sediment TP concentrations ranged between 269 and 465 µg g?1 and were highest in fine sediment fractions. Acid‐extractable P, a non‐bioavailable form, represented at least 95% of sediment TP. A positive relationship was observed between VHG and TP in two of the gravel bars, with wells that were strongly downwelling having lower TP concentrations. These results suggest that in downwelling zones, hyporheic sediments can trap surface‐derived dissolved P, and that much of this P becomes stored in refractory particulate forms. Bioavailable P is mainly present in dissolved form and only occupies a small fraction of total P, with particulate P comprising the majority of total P. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

5.
Concentrations of polychlorinated dibenzo-p-dioxins (dioxins)(PCDDs) and polychlorinated dibenzofurans (PCDFs)(furans) in sediments from Port Jackson ranged from 32 to 4352 pg WHO-TEQ DF g(-1)dw with a mean of 712 pg g(-1)dw. Maximum total dioxins plus furans concentrations in this sediment was 6,290,000 pg g(-1)dw, which is the highest recorded in Australia and among the highest reported for sediment globally. Permanent bans were placed on fin fishing and prawn trawling in February, 2006 for the whole estuary, based on dioxin tissue burdens. A distinct congener profile corresponded to chemicals known to have been produced by industry on the shores of Homebush Bay in the upper estuary. These chemicals are being dispersed extensively and exceed pre-anthropogenic concentrations in even distant, less developed parts of the harbour. Remediation of sediments is currently being undertaken, with the intention of containing dispersion of dioxins and reducing body burdens in fin fish and prawn populations.  相似文献   

6.
王琦  姜霞  金相灿  徐玉慧 《湖泊科学》2006,18(2):120-126
采用EDTA螯合剂法和不同的化学提取法,研究了太湖3个不同营养水平湖区中8个位点表层沉积物总磷、各组分磷及生物可利用磷的含量分布,探讨了太湖不同营养水平湖区表层沉积物的释磷潜力和生物可利用磷的来源.结果表明,太湖不同营养水平湖区表层沉积物总磷、无机磷和生物可利用磷含量分布差异较大,且与各湖的营养水平相一致.有机磷含量与有机质和含水率显著相关;沉积物中Fe-P和Ca-P对生物可利用磷的贡献较大,这部分磷具有较大的潜在释放风险.  相似文献   

7.
Influence of wave on sediment resuspension and nutrients release from sediments, collected from Lake Taihu and Lake Chaohu, was studied in flume experiments. Under strong-wave conditions, concentrations of suspended solids (SS), total phosphorus (TP) and dissolved total phosphorus (DTP) in overlying water were increased significantly following the sediments re-suspension. During the experiments on sediments of Lake Taihu and Lake Chaohu, TP concentrations increased 6 times and 3 times, and DTP concentration increased 100% and 70% more than it in presuspension, respectively. Concentration of soluble reactive phosphorus (SRP) of experiment on sediment of Lake Taihu increased 25%. During the massive sediment suspension, the dissolved phosphorus in pore water and much of the phosphorus adsorbed by the sediment particles were released into overlying water. The phenomena in this wave flume experiment are quite similar to the situation observed in situ of Lake Taihu. The critical wave stresses of sediment re-suspension are nearly equal. The change of concentrations of SS, TP, and SRP was the same as that in situ situation. This study showed that concentrations of TP and SRP in lake water could be increased significantly by wave disturbance. Phosphorus release was significantly enhanced by wave disturbance at the beginning of massive sediment re-suspension, but decreased later.  相似文献   

8.
太湖表层沉积物中有机氯农药残留及遗传毒性初步研究   总被引:9,自引:2,他引:7  
赵中华  张路  于鑫  李正魁 《湖泊科学》2008,20(5):579-584
采用GC-ECD对太湖表层沉积物中的有机氯农药含量进行了定性定量分析.太湖20个采样点均有不同程度的有机氯农药检出,16种有机氯农药总量为4.22-460.99ng/g(dw),北部湖区、潮心区以及沿岸区等均有高值点出现,与沉积物有机质含量、氮磷营养盐含量分布并不一致.检出率最高的有机氯农药组分为DDTs、HCHs.DDTs含量检出顺序为P,P'-DDT>P,P'-DDD>P,P'-DDE,说明环境中可能仍然具有DDT箱入特征;HCHs中?HCH,?HCH检出相当,怃-HCH检出较高,主要为早期残留.结合鼠伤寒沙门氏菌/哺乳动物微粒体酶系(Ames)试验研究太湖典型溯区表层沉积物中有机污染物的遗传毒性,初步确定可能的生态风险因子.  相似文献   

9.
Influence of wave on sediment resuspension and nutrients release from sediments, collected from Lake Taihu and Lake Chaohu, was studied in flume experiments. Under strong-wave conditions, concentrations of suspended solids (SS), total phosphorus (TP) and dissolved total phosphorus (DTP) in overlying water were increased significantly following the sediments re-suspension. During the experiments on sediments of Lake Taihu and Lake Chaohu, TP concentrations increased 6 times and 3 times, and DTP concentration increased 100% and 70% more than it in presuspension, respectively. Concentration of soluble reactive phosphorus (SRP) of experiment on sediment of Lake Taihu increased 25%. During the massive sediment suspension, the dissolved phosphorus in pore water and much of the phosphorus adsorbed by the sediment particles were released into overlying water. The phenomena in this wave flume experiment are quite similar to the situation observed in situ of Lake Taihu. The critical wave stresses of sediment re-suspension are nearly equal. The change of concentrations of SS, TP, and SRP was the same as that in situ situation. This study showed that concentrations of TP and SRP in lake water could be increased significantly by wave disturbance. Phosphorus release was significantly enhanced by wave disturbance at the beginning of massive sediment re-suspension, but decreased later.  相似文献   

10.
This study provides baseline information on the extent of contamination in sediments of the Jobos Bay estuary and surrounding areas in Puerto Rico. Sediments from Jobos Bay area (n = 14) had higher overall average concentrations than those from La Parguera area (n = 5, used as reference site), in μg/g dw, for As (17 vs 9), Cu (29 vs 14), Pb (11 vs 4), and Zn (64 vs 28); and in %, for Fe (2.6 vs 0.6). Sediments (n = 8) screened for PAHs and PCBs exhibited total concentrations (ng/g dw) that ranged from 40.4 to 1912, and from not detected to 11.21, respectively. The quality of sediments of Jobos Bay could be classified as low to moderate pollution. The proximity to anthropogenic sources of contamination warrants a monitoring program for inorganic and organic pollutants in Jobos Bay area for an effective coastal management program of this tropical ecosystem.  相似文献   

11.
太湖沉积物理化性质及营养盐的时空变化   总被引:10,自引:3,他引:7  
在不同季节,采集太湖梅梁湾和贡湖湾沉积物柱状样,研究沉积物Eh、pH、总氮、总磷以及有机质四季垂向剖面分布变化特征.研究结果表明,在表层下(0-3 cm),Eh随沉积物深度的增加迅速下降,很快进入还原状态.沉积物剖面上pH变化幅度不大,在6.4-7.8之间,冬季沉积物pH均有所降低.太湖沉积物中含有丰富的营养盐,总氮和总磷最高浓度分别为2.68和0.864 mg/g,其剖面分布特征表明,沉积物表层总氮和总磷含量远高于底层,其含量随深度增加而降低,但四季变化趋势不明显.沉积物中有机质含量在10 cm以上变化幅度较大,随着沉积物深度的增加,有机质含量明显减少,季节变化幅度不大.比较不同采样点发现,位于梅梁湾生态系统试验区内的S1位点沉积物氮磷内源负荷最大.  相似文献   

12.
In July 1978, total phosphorus and organic carbon were determined in the sediments of Tolo Harbour, a sewage-polluted estuary in north-east Hong Kong. Concentrations were correlated with % silt-clay in each of three areas. Phosphorus concentrations were highest in central Tolo Harbour, lower by about 1.5μg at. P g?1 in the outer estuary, Tolo Channel, and lowest in the polluted inner reaches near large coastal reclamations. The latter values, about 3.0 μg at. P g?1 lower than in central Tolo Harbour, might reflect a selective adsorption of phosphate by reclamation sediments. Organic carbon concentrations were high in the inner reaches and decreased towards the outer channel. Correlations between phosphorus and organic carbon were compared with a published correlation for the east coast of England: in Hong Kong, phosphorus concentrations showed a smaller increase as organic carbon increased, and reached only one-third of the English values as organic carbon approached 2.0%.  相似文献   

13.
以巢湖重污染入湖河流双桥河为研究对象,研究了底泥疏浚对水质以及沉积物中总氮、总磷和有机质的短期影响及长期效应.结果表明,双桥河水质的季节变化显著,受上游城市污水及周边面源污染的影响,疏浚对水质改善作用不明显.表层沉积物中总氮、总磷及有机质含量在疏浚结束后1个月有所降低,但是2年后分别回复到疏浚前的189.77%、111.62%和152.87%.疏浚结束2年后,沉积物中磷主要以钙磷和有机磷的形式存在,铝磷和铁磷的含量较少,弱结合态磷的含量最低;但是表层沉积物中的弱结合态磷、铝磷和铁磷结合态磷含量较疏浚前分别升高了728.32%、13.52%和37.73%,并呈现出表层富集现象,存在较高的污染物释放风险.这可能是由沉积环境改变、外源污染未得到有效控制引起的.因此,为了维持疏浚的长期效果,应该对外源污染源进行有效控制.  相似文献   

14.
滇池水体不同形态磷负荷时空分布特征   总被引:1,自引:1,他引:0  
利用Arc GIS空间插值的方法,通过2013年逐月监测(12个月)36个站点水量及不同形态磷浓度,揭示滇池水体磷浓度和磷负荷的时空变化,并探讨不同形态磷负荷的组成贡献,旨在为进一步实施滇池水污染治理及污染负荷控制提供依据.结果表明:滇池水体总磷(TP)浓度在0.13~0.46 mg/L之间,其中颗粒态磷(PP)浓度占TP浓度的72.6%,溶解性活性磷(SRP)浓度占TP浓度的12.8%,溶解性有机磷(DOP)浓度占TP浓度的14%;2013年水体TP负荷为251 t/a,其中PP负荷为190 t/a,SRP负荷为26 t/a,DOP负荷为34 t/a;滇池水体PP负荷对TP负荷的贡献最大,为76%,其次为DOP和SRP,贡献分别为13%和10%;TP及不同形态磷浓度与其负荷在季节分布上差异显著,负荷随季节变化呈现秋、冬季较高,春、夏季较低,而浓度呈现夏、秋季较高,冬、春季相对较低的趋势.定量评估滇池水体不同形态磷负荷及其组成贡献,对进一步揭示滇池藻源和泥源内负荷对水污染的贡献具有重要意义.  相似文献   

15.
Oligochaete communities were used to assess the biological recovery of sediments after the abatement of eutrophication in Lake Geneva (Switzerland). In 1995, mean relative abundance of oligotrophic worm species (OS) was around 30% in areas of low organic sedimentation (LOS) whereas, in areas of high organic sedimentation (HOS), it was below 15%. The abundance of OS observed in LOS areas was close to values predicted from total phosphorus (TP) concentrations in the water. Recovery from eutrophication proceeded at the same pace in the water (TP) and in the sediment (OS) of LOS areas, whereas it was delayed in the sediment of HOS areas. Lake Geneva was mesotrophic according to the oligochaete communities of LOS areas, but it was meso-eutrophic according to those of HOS areas.  相似文献   

16.
17.
余成  陈爽  张路  王兆德  申秋实  高群 《湖泊科学》2017,29(2):334-342
磷是坦噶尼喀湖生态系统中必不可少的营养元素,直接决定湖体初级生产力的高低,进而影响到周边居民对于动物蛋白的获取来源.为了解坦噶尼喀湖磷的外源输入,选择湖泊东北部的入湖河流,对表层沉积物(16个样点)中总磷(TP)和各形态磷含量及其分布特征进行分析,并探讨磷的形态分布特征与土地利用方式之间的相关关系.结果表明,入湖河流沉积物TP含量为73.05~239.94 mg/kg,平均含量为152.64±55.37 mg/kg,其中最高值出现在马拉加拉西河口.采用Psenner法对磷进行连续浸提并比较不同形态磷含量,由高及低依次为铁铝结合态磷(Fe/Al-P)钙结合态磷(CaP)有机磷(Org-P)残渣态磷(Res-P)弱吸附态磷(Labile-P).土地利用类型对TP及各形态磷含量影响较大,其中TP含量表现为河口湿地城镇附近林草地区,表明地表径流和人类活动会对TP含量产生影响,而对于不同形态磷含量,Laible-P、Fe/Al-P、Org-P含量均表现为河口湿地林草地城镇附近,Ca-P、Res-P含量均表现为城镇附近河口湿地林草地.分析沉积物理化性质与各磷形态之间的相关性,发现沉积物总氮(TN)、有机质和总有机碳与Fe/Al-P、LabileP和TP相关性较好,与Org-P、Ca-P和Res-P相关性较差,表明TN和有机质的输入,会伴随沉积物中磷含量的升高,其增量的赋存形态主要为氧化还原敏感态磷和Labile-P.沉积物粒径组成与各磷形态含量存在相关性,细粒径沉积物与各形态磷含量呈显著正相关,粗粒径沉积物与各形态磷呈显著负相关,表明细小颗粒更易吸附磷.  相似文献   

18.
Using sediment traps, we aimed to elucidate the temporal and spatial variations in sediment fluxes in large and shallow Lake Peipsi, over the May to October 2011 period, and analyze the factors behind those variations. The effects of weather factors (mean and maximum wind velocity, water level and water temperature) on sediment resuspension and the concentrations of suspended solids (SS), total phosphorus (TP), soluble reactive phosphorus (SRP), and chlorophyll a (Chl a) were investigated. Moreover, the internal loading of TP due to sediment resuspension was determined. The sediment resuspension rates were significantly higher in the shallower waters than in the deeper parts of the lake. Resuspension was a major factor in sedimentation dynamics of the lake, which is presently subject to eutrophication. The rates of sediment resuspension followed the same pattern as gross sedimentation during the study period, and their respective values differed significantly between sampling dates. The highest resuspension rates were observed in September (mean 55.4 g dw m?2 day?1), when the impacts of wind events were particularly pronounced. Weather factors that were recorded approximately 2 weeks before water and sediment sampling affected the gross sedimentation and sediment resuspension. The water quality variables of SS, TP, SRP, Chl a were similarly affected. During the study, TP concentrations of the water were mainly determined by the resuspension of sediments containing a large pool of organic material. Although internal loading of TP due to resuspension was several times greater than external loading, external loading determines the amount of phosphorus that enters the lake and can be resuspended.  相似文献   

19.
Forms of phosphorus in sediments from 25 lakes in the middle and lower reaches of Yangtze River were analyzed by the sequential extraction procedure. Contents and spatial distrubution of algal available phosphorus (AAP) in sediments of Lake Taihu, the third largest freshwater lake of China, were also studied. Relationships between phosphorus forms in sediment and macrophytes coverage in sample sites, as well as phosphorus forms in sediments and chlorophyal contents in lake water were discussed. Exchangeable form of phosphorus (Ex-P) in surface sediments was significantly positive correlative to total phosphorus (TP), dissolved total phosphorus (DTP) and soluble reactive phosphorus (SRP) contents in the lake water. Bioavailable phosphorus (Bio-P) contents in sediments from macrophytes dominant sites were significantly lower than that in no macrophyte sites. In Lake Taihu, Ex-P content in top 3 cm sediment was highest. However, content of ferric fraction phosphorus (Fe-P) was highest in 4–10 cm. Bioavalilble phosphorus (Bio-P) contents in surface sediments positively correlated to Chlorophyll a contents in water of Lake Taihu with significant difference. Therefore, contents of Bio-P and AAP could be acted as the indicators of risks of internal release of phosphorus in the shallow lakes. It was estimated that there were 268.6 ton AAP in top 1 cm sediments in Lake Taihu. Sediment suspension caused by strong wind-induced wave disturbance could carry plenty of AAP into water in large shallow lakes like Lake Taihu.  相似文献   

20.
Determinations of dissolved reactive and total dissolved mercury, particulate and sedimentary mercury, dissolved organic carbon (DOC), particulate organic carbon (POC) and suspended particulate matter (SPM) have been made in the estuary of river Douro, in northern Portugal. The estuary was stratified by salinity along most of its length, it had low concentrations of SPM, typically <20 mg dm(-3), and concentrations of DOC in the range <1.0-1.8 mg dm(-3). The surface waters had a maximum dissolved concentration of reactive mercury of about 10 ng dm(-3), whereas for the more saline bottom waters it was about 65 ng dm(-3). The surface waters had maximum concentrations of total suspended particulate mercury of approximately 7 microg g(-1) and the bottom waters were always <1 microg g(-1). Concentrations of mercury in sediments was low and in the range from 0.06 to 0.18 microg g(-1). The transport of mercury in surface waters was mainly associated with organic-rich particulate matter, while in bottom waters the dissolved phase transport of mercury is more important. Lower particulate organic matter, formation of chlorocomplexes in more saline waters and eventually the presence of colloids appear to explain the difference of mercury partitioning in Douro estuarine waters.  相似文献   

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