首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到17条相似文献,搜索用时 93 毫秒
1.
滇池现代沉积物中磷的地球化学及其对环境影响   总被引:47,自引:2,他引:47  
湖泊沉积物中,磷是产生富营养化的重要元素.湖泊中磷元素含量、地球化学行为以及它的复杂矿物学特征,使人们对磷的研究极为重视.滇池湖中总磷超标10.3倍,底泥沉积物中P2O5平均含量0.52%,最高可达1.92%.滇池地处磷矿区,是磷质来源最丰富的湖泊,统计表明,磷含量每年在不断增长.滇池沉积物中磷主要以吸附态、有机态、铁结合态、钙结合态、铝结合态等几种形式存在.这些形态磷在底泥中是不稳定的,它们在环境改变条件下,又将磷释放到水体中.微生物在磷的循环过程中起了重要作用,乳酸菌对不溶性磷酸盐的分解,使湖泊中可溶磷含量增高.聚磷菌对磷元素的富集以及聚磷菌死亡后发生有机磷的矿化作用,是湖泊中水合磷酸盐矿物沉积的重要途径.当湖泊中这种不稳定的水合磷酸盐矿物在条件具备的情况下,经沉积物覆盖成岩作用后,最终形成磷灰石。  相似文献   

2.
太湖及其主要入湖河流沉积磷形态分布研究   总被引:57,自引:6,他引:57  
选择了我国第三大浅水湖泊--太湖及其主要入湖河流进行沉积磷形态的连续提取研究.太湖湖区沉积磷中不稳态磷(LP)及铝结合态磷(Al-P)含量很低,其余形态磷为铁结合态磷(Fe-P)<钙结合态磷(Ca-P)<有机磷(Org-P).河流沉积物中有机磷的相对含量高于湖泊沉积物,绝对含量平均值约为湖泊沉积物的3.9倍,铁结合态磷的绝对含量约为湖泊沉积物的3/4,湖区沉积物Fe-P含量与水体中PO3-4-、Chla呈显著正相关关系,同时与间隙水的氧化性呈显著负相关关系.太湖各湖区沉积物的磷形态表现为空间差异较大,活性组分的差异性要大于活性较差的组分.总的来说北部湖区沉积物中Fe-P和Org-P含量高于其他湖区,这与太湖北部湖区水体高营养级和藻类爆发关系密切.湖区沉积磷的垂直分布规律较复杂,既有随深度增加的,也有随深度降低的,河流沉积物同样如此.这与太湖及河流生态条件、污染物排放以及沉积动力学条件不同有关.  相似文献   

3.
红枫湖、百花湖沉积物中磷的存在形态研究   总被引:35,自引:1,他引:34  
湖泊沉积物中磷存在形态,是理解湖泊系统中磷的生物地球化学循环的重要方面,对研究湖泊富营养化等环境问题具有重要意义。本次工作中,采用连续提取化学分析技术,对红枫-百花尖沉积物中磷的存在形态及其剖面变化进行了研究,磷的存在形态包括:吸附态磷(Losely sorbedP)、铁结合态磷(Fe-bound P)、钙结合态磷(Ca-bound P)、矿物晶格中结合力强的残留态磷(Detrial-P)和有机态  相似文献   

4.
长江口海域表层沉积物中磷的形态分布及环境意义   总被引:4,自引:0,他引:4  
用分级浸取的方法对2009年2月采自长江口海域27个表层沉积物样品中P的形态和相关环境特征进行了研究。结果表明,物质来源和沉积物粒度是各形态P的含量与分布的主要控制因素。Ex-P(可交换态磷),Fe-P(铁结合态磷),Al-P(铝结合态磷),Lea-OP(可浸取有机磷)和CFA-P(自生钙磷)5种形态的沉积磷在适当条件...  相似文献   

5.
密云水库沉积物-水界面磷的地球化学作用   总被引:11,自引:4,他引:11  
以密云水库为例,研究了水库沉积物中有机质的含量与有机磷的关系,表明表层沉积物中的总有机碳和有机磷的含量都明显高于底层,是由于一些以磷为营养素的富营养化指示藻类在水体中逐年增加,它们死亡后的残骸经分解-矿化后在底积物中累积的结果。沉积物和孔隙水中磷的剖面特征研究表明,表层沉积物和孔隙水中的磷都有明显上升的趋势,是由于沉积物的表层微生物和活性有机碎屑层比较丰富,有机质降解和含磷的有机化合物分解,使溶解性磷酸盐进入孔隙水。对沉积物磷形态、总有机碳及孔隙水中总磷对磷释放的影响进行了线性相关分析,结果表明上覆水中的磷主要来自沉积物的铁结合态磷、铝结合态磷、溶解态磷三种形态,孔隙水中总磷以及总有机碳含量对上覆水中总溶解磷浓度存在较大的影响,这些为研究水库沉积物作为水库内污染源对水质的影响提供了基础资料。  相似文献   

6.
南海湖沉积物中Hg的形态分布特征   总被引:2,自引:0,他引:2  
以包头市南海湖为研究对象,采用连续化学提取法,系统开展了沉积物中Hg的形态分布研究。结果表明,表层沉积物中Hg含量的水平分布总体呈现湖心区低,西南和东北部湖区高的趋势。腐殖酸结合态为表层沉积物中Hg的主导形态,次为交换态和水溶态。表层沉积物中生物有效态Hg的含量甚高,占总汞的76%~94%,对整个生态系统具有潜在危害性。沉积柱芯中总Hg表现为表层富集并随深度增加而降低的变化趋势。B、F站位柱状沉积物中腐殖酸结合态Hg随深度有规律的递减,H站位20 cm以上Hg的主导形态为腐殖酸结合态,残渣态次之;20~30 cm的主导形态则为残渣态及可交换态。  相似文献   

7.
水体中富营养化水平与磷元素的赋存形态密切相关。目前围绕引起富营养化关键因子之一的磷形态的垂向分布特征、各磷形态间的迁移转化行为及其影响因素取得了比较明确的研究进展。为进一步揭示不同磷形态在沉积物-水体系中迁移转化行为随时空的变化特征,本文采用磷钼蓝分光光度法对沱江流域简阳段间隙水中可溶性活性磷(SRP)、可溶性非活性磷(SUP)及总溶解性磷(TDP)进行测定;采用SMT法和改进的沉积物无机磷形态连续提取法对沉积物中总无机磷(TIP)、总磷(TP)、难提取磷(Res-P)、可交换态磷(Exc-P)、铁结合态磷(Fe-P)、铝结合态磷(Al-P)、钙结合态磷(Ca-P)进行提取,磷钼蓝分光光度法进行测定,以揭示沉积物-水体系中磷的赋存形态垂向分布行为特征,并将实验数据与十年前该地区磷的赋存形态结果进行对比,探讨磷赋存形态的变化趋势及影响因素。结果表明:间隙水中SRP、SUP和TDP的含量分别为0.004~0.36mg/L、0.080~3.19mg/L和0.056~3.28mg/L;沉积物中TP、TIP、Res-P、Exc-P、Al-P、Ca-P含量分别为1235.40~1646.94mg/kg、860.00~1318.59mg/kg、130.31~537.13mg/kg、1.35~14.10mg/kg、0.007~0.12mg/kg、743.13~1109.91mg/kg,Fe-P未检出。对比十年前后沉积物-水体系中磷赋存形态的变化可知,由于受到外源磷输入的影响,间隙水中SRP、SUP以及TDP含量虽然在-10cm以上变化不明显,但在-10cm以下明显增大,且导致沉积物中TP、TIP含量增加;偏碱性的沉积环境导致Al-P的释放,其含量明显减小;Exc-P含量的减小与其转化为稳定的Ca-P或Res-P形态有关。研究认为:随着时空的变化,沱江简阳段沉积物呈现外源磷输入和内源磷释放的综合污染。总体而言,由于输入的磷形态大部分以稳定的Ca-P和Res-P形态存在于沉积物中,使得表层间隙水中生物可直接利用的磷含量总体变化不大,该地区富营养化程度不会加重。维持沉积环境的弱碱性,有利于Al-P、Exc-P等向Ca-P的有效转换,抑制河流富营养化。  相似文献   

8.
密云水库沉积物中磷的形态和分布特征   总被引:26,自引:3,他引:26       下载免费PDF全文
采用连续提取化学分析技术,对密云水库的柱状沉积物和表层沉积物样品进行了磷形态的提取分析,研究了各种形态磷在表层及垂立方向上的分布特征。分析结果表明,密云水库沉积物中以无机磷为主,有机磷次之,无机磷占总磷的76.88%。95.09%。沉积物中总磷及其不同形态无机磷在垂直方向上的分布变化规律为:总磷、可溶态磷含量随深度增加而降低,Ca—P合量随深度增加而增加,Al—P和闭蓄态磷变化幅度不大,Fe—P、有机磷的垂直方向变化情况较复杂。潮、白河流域总磷与各形态磷在表层及垂直方向上的分布差异在一定程度上反映出近年来水库所受上游流域工业活动和人为污染的影响情况。  相似文献   

9.
采集了7组滇池近代沉积物柱芯,测定了其中总P(TP)、Fe、Al、Ca的含量,并首次获得了埋深大于25 cm的沉积物的不同形态磷的数据,分析了TP与不同形态磷的时空分布特征及TP与总Fe、Al、Ca含量的关系,探讨了滇池内源磷释放潜力的区域差异和制约因素。结果表明,自北向南,TP含量出现随深度先升高后降低的变化特征,各形态P之间的关系为:碎屑磷(DP)>有机磷(OP)≈铁结合态磷(Fe-P)>闭蓄态磷(Oc P)>钙结合态磷(Ca-P)>铝结合态磷(Al-P)>可交换态磷(SRP)。纵向上Fe-P随深度逐渐升高,Oc P逐渐降低,其它形态P的变化规律不明显;区域上TP、DP、OP、Fe-P、Ca-P和Al-P南部高于北部。在滇池南部DP通量较高的区域,TP与Fe、Al呈正相关关系,与Ca呈负相关关系,其它区域无相关性。分析表明,滇池南部内源磷的释放潜力大于中部和北部,而南部内源磷受DP输入的影响,风浪扰动对北部内源磷的释放有更强的抑制作用。  相似文献   

10.
为了控制水体富营养化,对沉积物中磷的分布特征进行了研究。在海河干流采集13个表层沉积物和表层水样,采用逐级提取法获得可交换态磷(NH4Cl-P)、可还原态磷(BD-P)、铁铝结合磷(NaOHP)、钙磷(HCl-P)和残渣态磷(Res-P),分析各形态磷空间分布及其对水相(间隙水、表层水)磷的影响。结果表明:海河干流表层沉积物中总磷质量分数较高,为808.5~1 698.7mg·kg-1,上游和下游的采样点含磷量较低,中游采样点含磷量较高;不同形态磷的质量分数差异较大,NH4Cl-P、BD-P、NaOH-P、HCl-P和Res-P的质量分数变化范围分别为8.1~31.1、41.9~84.9、151.6~348.2、312.2~819.9、226.8~1 003.0mg·kg-1,分别占总磷(TP)的0.65%~1.85%、3.19%~6.57%、10.8%~24.34%、20.26%~52.18%、24.41%~58.33%;间隙水中总溶解性磷与沉积物中NH4Cl-P、BD-P、NaOH-P的质量分数相关性较高,相关系数分别达到0.892、0.848、0.749。研究结果表明海河内源磷释放的主要控制方向为NH4Cl-P、BDP、NaOH-P。  相似文献   

11.
 Sediments in the rivers and basins around Washington, DC, have high concentrations of phosphorus, which, based on geographic distributions, is largely derived from urban runoff and municipal sewage. Dissolved-particulate phosphate exchange reactions and biological uptake of dissolved phosphorus from the water column may be an added source of phosphorus to the sediments. Concentrations of total sedimentary phosphorus ranged from 24 to 56 μm P/g-dw, and were highest in areas near combined sewer outfalls. As a part of this study, sedimentary phosphorus was fractionated into Fe-P, Ca-P, Al-P, and organic phases using a selective-sequential leaching procedure. The distribution of the phases in all sediments analyzed follow the order , Fe-P>Ca-P>Al-P. Spatial variations in the amounts of phosphorus in the different phases is related to the sources of phosphorus to the area. The proportions of occluded Al-P and organic P are 10–20% of the total P, respectively. This suggests that phosphorus from natural sources is small compared to anthropogenic inputs in this area. The high leachable Fe-P and Ca-P in these sediments might contribute a substantial amount of P to the water column under conditions of remobilization. Received: 20 February 1996 · Accepted: 2 April 1996  相似文献   

12.
There were many differences between rivers and lakes such as flow velocity, hydraulic retention time, water vegetation community and other chemical-physical factors that may lead to different characteristics of sedimentary phosphorus. In our research, sedimentary phosphorus fractions and its phosphorus adsorption differences between the lower Nansi Lake and its main inflow rivers were compared. The results showed that the contents of NaOH-P, Org-P, IP-P, and TP in lake sediments were obviously higher than those in its inflow river sediments while HCl-P had no obvious difference between them. Based on analysis, the unstable NaOH-P would accumulate in lake sediments, while it is difficult for it to retain in sediments of rivers because of a high frequency of flood flows and unstable bed sediments. In addition, water vegetation communities were helpful in the accumulation of Org-P in lake sediments. From phosphorus adsorption experiments results, the Ceqc (equilibrium concentration of phosphorus release/adsorption) of lake sediments was higher than that of river sediments. It was indicated that sedimentary phosphorus would be more easily released from lake sediments than river sediments. So in future more work should be focused on internal P loading from lake sediments release.  相似文献   

13.
The Daliao river system in China has been seriously affected by long-term intensive industrial, urban and agricultural activities. The objectives of this study were to determine the total phosphorus (TP) content and forms of phosphate in the sediments and investigate geochemical relationships between P forms and sediment mineral phases. Twenty-seven samples of surface sediments were collected and analyzed for P and major elements. Chemical forms of phosphate in the sediments were measured by sequential selective extraction method. Results indicate that TP in the sediments of the Daliao river system averaged 703 mg kg−1, in the range from 206 to 1,342 mg kg−1. The sediments in the tributaries and near cities contained high TP, due to discharge of municipal and industrial effluents. The distribution of phosphate in the various mineral phases followed the order: Ca-P > RES-P > RS-P > Fe-P > Al-P > S/L-P for the Hun river and Taizi river, and Ca-P > Fe-P > RES-P > RS-P > Al-P > S/L-P for the Daliao river. Fe and Ca contents in the sediments were positively correlated to Fe associated P (Fe-P and RS-P) and Ca-P, respectively. In addition, sediment organic matter, Fe and Ca contents were positively correlated to TP in the sediments. However, Al content was not correlated to Al-P or TP in the sediments. Generally, the sediments contaminated by effluents and in tidal zone contained more bioavailable P. Possible release of P from these sediments to overlying water might pose potential risk on estuarine eutrophication.  相似文献   

14.
平水期洞庭湖不同形态磷赋存特征   总被引:4,自引:0,他引:4       下载免费PDF全文
王丛丹  汪金成  杨宇  钱宝  杨朝云  阎梅 《水文》2019,39(6):74-79
通过现场调查和室内实验,对平水期洞庭湖24个断面上覆水-沉积物磷的污染程度、分布特征进行研究;同时,分析了各形态磷间的相关性,探讨了磷的赋存形态对水体富营养化的影响、沉积物释放量和释放风险。结果表明,水体内总磷分布规律为南洞庭西洞庭东洞庭大通湖,东洞庭湖以颗粒态磷为主,西洞庭湖、南洞庭湖、大通湖均以溶解态磷、无机磷为主。沉积物中总磷的分布规律为南洞庭西洞庭东洞庭大通湖。东洞庭湖、西洞庭湖、南洞庭湖则以Ca-P为主,大通湖以Fe/Al-P为主。Ca-P与Fe/Al-P呈现较显著的负相关关系。大通湖释放风险较大,可释放量大;东洞庭湖有一定的可释放量,应对这两个湖泊给予较多的关注。与国内其他湖泊比较,洞庭湖沉积物中TP处于中下水平,IP在沉积物中占据较高比例。湖区沉积物中Fe/Al-P与水体中DIP、DTP、TP均具有较显著的负相关关系,存在磷的内源释放。  相似文献   

15.
北京平原沉积物稀土元素地球化学特征及物源意义   总被引:2,自引:0,他引:2  
文中总结了北京平原永定河、潮白河流域钻孔沉积物中稀土元素分布特征,两流域沉积物稀土元素总量∑REE、轻重稀土比(LREE/HREE)及轻(La/Sm)N、重(Gd/Yb)N稀土分馏特征差异较为显著。粒度对沉积物稀土分布(总量、轻重稀土比及分馏特征)有一定影响;各流域沉积物均表现为轻稀土相对富集、弱Eu负异常的球粒陨石标准化曲线。细颗粒沉积物稀土分馏特征(La/Yb)N有较好的物源示踪意义。根据沉积物(La/Yb)N值对永定河、潮白河交互沉积区不同深度沉积物进行了物源示踪,不同深度上沉积物来源不同。此外,同一流域上、中、下游沉积物稀土分馏特征不同。常量元素Al2O3/Fe2O3与稀土元素(La/Yb)N划分结果相符,但精度低于稀土元素物源分析。  相似文献   

16.
The fatty acid composition of sediments from Narragansett Bay show significant variation between certain areas of the Bay. Both the organic carbon and fatty acid concentrations decrease with increasing distance from the Providence River area—an area which received municipal sewage and industrial effluents. The ratio of the fatty acid concentration to organic carbon concentration is fairly constant for all stations sampled. The variations in the relative abundance of fatty acids may reflect either the influence of fatty acids discharged to the river area by sewage effluents or the synthesis of fatty acids by microbial populations which probably differ for the areas compared. Temporal variations in fatty acid composition and fatty acid concentration are minimal. Lipolytic activity has been demonstrated and probably acts on glycerides deposited to the sediments releasing free fatty acids shortly after deposition. A model for the diagenesis of fatty acids in Recent sediments is proposed based upon the above findings and upon earlier reports by the authors and by other investigators.  相似文献   

17.
Increasing eutrophication and seasonal anoxia in bottom water in the Changjiang Estuary and its adjacent waters has progressed in recent decades, caused by elevated anthropogenic N and P input. Sedimentary biogenic elements were investigated to determine whether the biogenic proxies could be used in paleoenvironmental studies in an energetic estuary, as well as to reconstruct the histories of environmental changes in the East China Sea (ECS). Two 210Pb-dated cores from the coastal and offshore waters were analyzed for organic C (TOC) and its stable isotope (δ13C), total N (TN), biogenic Si (BSi), total P (TP) and P species. In coastal sediment, the variations of P species, especially Fe-P, Al-P and detrital apatite P (Det-P), reflected the dry–wet oscillations in the Changjiang River for the past century, which has influenced the sediment grain size and terrestrial material input. Much lower BSi content (0.756%) at 16–22 cm likely recorded the pronounced decrease in silicate flux in the Changjiang River and its lower flow in the late 1980s. In offshore sediment, higher concentrations of TOC, TN, BSi, Ex-P, Fe-P and Lea-OP indicated higher primary productivity in response to the strong winter monsoons during the 1960s–1980s, and their 20-a fluctuations were in agreement with the decadal variations of the winter monsoon. Low contents and little variations of Al-P and Det-P indicated the slight influence of the terrestrial sediment input in offshore waters. The influence of human activities on the environment in recent decades has also been recorded in coastal sediment. Grain-size normalized concentrations of TOC, TN, TP, Ex-P, Fe-P and Lea-OP increased by 24%, 23%, 15%, 13% and 51% in the upper 16 cm of coastal sediment, indicating elevated P and N load and primary productivity since the 1990s. Elevated TN/TP ratios and decreased BSi/TOC recorded the changed nutrient structure and the decrease in the proportion of the diatom to phytoplankton community. However, the sediment record indicated that the eutrophication might actually have started from the end of the 20th century rather than the reported middle of 20th century. In contrast, biogenic elements in offshore sediment did not reflect disturbance by human activities. This study revealed that multi-nutrient proxies in sediment in the ECS could indicate natural environmental changes including runoff and the winter monsoon over the past century, as well as the influence of human activities in recent decades. Phosphorus species with distinct origins and biogeochemical behaviors could effectively reflect different aspects of past environmental conditions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号