鸣翠湖间隙水与上覆水中氮、磷的分布特征研究

为探究湖泊沉积物与水体中氮、磷的迁移规律,收集鸣翠湖5个代表性采样点的间隙水和上覆水,测定TP、TN、氨氮等浓度,分析氮、磷的分布特征。通过相关性分析对间隙水和上覆水中氮、磷的关系作初步探讨,最后对鸣翠湖水体富营养化状况进行评价。结果表明:鸣翠湖间隙水和上覆水中氮、磷浓度梯度明显,具有间隙水向上覆水释放的趋势,其湖泊富营养化污染的内源作用已经非常明显。间隙水中TP、TN、氨氮的平均质量浓度分别为0.15、3.83、2.23mg/L;上覆水中TP、TN、氨氮的平均质量浓度分别为0.07、2.17、0.24mg/L。鸣翠湖水体已呈现出富营养化状态。     

过氧化钙缓释材料对河道水固磷及底泥控磷的机理研究

用聚乙二醇2000(PEG2000)和硬脂酸(SA)包埋粉末过氧化钙(CP)成功制备了CP缓释材料CP@PEG2000-SA。比较了粉末CP和CP@PEG2000-SA对上覆水中溶解性总磷的影响和对底泥中磷酸铝盐(Al-P)、磷酸铁盐(Fe-P)和磷酸钙盐(Ca-P)的影响。结果表明,CP@PEG2000-SA投加量宜为1.8kg/m2,在CP用量相同的条件下计算得到粉末CP投加量为1.0kg/m~2。投加粉末CP在10d内上覆水中溶解性总磷浓度迅速降至最低后又上升,而投加CP@PEG2000-SA可以实现35d内溶解性总磷持续缓慢下降。上覆水中的内源性磷一般来自底泥中Fe-P的释放。投加粉末CP虽能固定Fe-P含量,但起不到长效作用,甚至可能导致Al-P的释放。投加CP@PEG2000-SA可控制氧气释放速率,稳定pH,使得上覆水中溶解性总磷向底泥中的Al-P、Ca-P和Fe-P转化,起到长效抑制底泥中内源性磷向水体释放并同时吸收水体中磷的双重效应,达到了控磷目的。     

水源水库沉积物磷的赋存形态及其与间隙水磷的关系

为了探明水源水库沉积物磷的赋存形态及其对水体磷的影响,采用连续提取方法,研究了周村水库沉积物中磷的赋存形态分布特征,并探讨了沉积物各形态磷与总磷、烧失量及间隙水中磷的相关性。结果表明,周村水库内源磷负荷较高,沉积物中TP表现出表层富集的现象,表层沉积物中TP空间分布存在较大差异,上游浅水区为554~563 mg·kg~(-1),库心附近为424~1 161 mg·kg~(-1),而坝前深水区高达812~2 969 mg·kg~(-1)。无机磷(IP)是总磷(TP)的主要成分,占TP的79.26%~89.12%,IP主要由铝/铁磷(Al/Fe-P)构成。沉积物中的Al/Fe-P含量很高,具有很大的磷释放潜能。沉积物中各形态磷的浓度垂向分布随深度增加而逐渐降低,其中B、C两点变化最为明显。相关性分析结果表明,间隙水PO3-4-P与Fe-P存在较好的相关性,说明Fe-P对周村水库沉积物间隙水中PO3-4-P浓度分布有着重要的影响,周村水库水体季节性分层导致恒温层厌氧情况的发生,Fe-P在厌氧还原条件下释放进入间隙水并向上覆水扩散,进而可能对水体水质产生影响。     

产芝水库底泥和其间隙水中氮、磷分布特征

在现场调查和样品采集的基础上,对产芝水库主要采样点底泥及其间隙水中TN、NH+-N、NO3--N和TP浓度进行了测定,并对底泥TN,TP和其间隙水中TN、总溶解性磷(TDP)浓度进行了相关性分析.研究结果表明,产芝水库底泥含水率和有机质含量在表层均较高;而底泥中氮、磷浓度自深度为10 cm处向表层多表现出增加的趋势,间...     

不同水温时底泥扰动对不同形态磷分布的影响

研究了江南地区典型水温条件下,底泥扰动对上覆水中不同形态磷迁移的影响.结果表明,不同水温条件下,底泥扰动均有利于上覆水中溶解态磷(即溶解性总磷酸盐(DTP),包括溶解性正磷酸盐(DIP)和溶解性有机磷(DOP))向底泥迁移.与对照试验相比,不同水温时的扰动均导致DIP/TP和DTP/TP明显降低.与初始状态(第0天时)相比,扰动导致DIP/TP分别降低了39.61百分点(冬季水温)和17.38百分点(夏季水温),而DTP/TP则分别降低了39.16百分点(冬季水温)和19.06百分点(夏季水温).相反,对照试验中,DTP/TP分别上升了24.90百分点(冬季水温)和23.37百分点(夏季水温).这说明底泥扰动促进了溶解态磷向颗粒态磷(PP)的转化.     

菖蒲对沉积物中各形态磷垂直分布的影响

在实验室模拟条件下,培育根系较发达的湿地植物菖蒲(Acorus calamus),以探究其对沉积物中各形态磷垂直分布的影响。结果表明:(1)实验60d后,对照组上覆水TP、溶解性活性磷(SRP)显著升高(P0.05),而菖蒲组上覆水TP、SRP降低。(2)对照组各形态磷含量在沉积物各深度之间无显著差异(P0.05)。菖蒲组沉积物中各形态磷含量(除盐酸提取磷)均不同程度低于对照组和初始值。菖蒲组沉积物中TP、有机磷、氢氧化钠提取磷在沉积物5cm处变化幅度最大,与初始值相比分别降低94.08、58.30、56.19mg/kg;无机磷在沉积物2cm处下降了35.40mg/kg。(3)菖蒲通过自身的生长吸收以及改变周围环境因子,直接或间接地影响了沉积物各形态磷的垂直分布。     

溶解氧对底泥扰动状态下水体中磷去除和固定的影响

以太湖梅梁湾底泥和上覆水为研究对象，通过实验室实验研究了底泥扰动状态下溶解氧水平（2～4mg／L、5～6mg／L、7～8mg／L）对上覆水中磷去除和固定的影响。结果表明，底泥扰动和溶解氧水平对上覆水中磷迁移有明显影响。扰动时间延长，溶解性磷酸盐（DIP）和溶解性总磷（DTP）均呈降低的趋势；但溶解氧水平提高，上覆水中DIP和DTP浓度有所增加。底泥扰动和溶解氧水平改变了悬浮物上不同形态磷的数量分布。随着溶解氧水平提高，NH4Cl-P（1～5d平均值）和Fe／Al—P（1～5d平均值）含量及其占总磷（Tot—P）的百分比均呈逐渐降低的趋势。另外，闭蓄态铁铝结合态磷（Fe／Al—P）占Fe／Al—P的比值从51．2％（2～4mg／L）增加至54．1％（7～8mg／L）。     

污水厂出水及下游大沽排污河磷形态及浓度变化规律研究

为分析研究不同污水厂出水及下游排污河磷形态及浓度的变化规律,2014年3—8月对污水厂A、B出水及其排污河下游与大沽排污河5个点位水体中的总磷(TP)、溶解性总磷(TDP)、溶解性无机磷(DIP)、溶解性有机磷(DOP)、颗粒态磷(PP)进行了动态监测。结果表明,各点位水体均以DIP为主,污水厂A出水TP变化范围为0.27~2.31 mg/L,均值为1.04 mg/L,下游各形态磷浓度低于出水浓度,污水厂B出水TP浓度范围为0.10~3.12 mg/L,均值为0.49 mg/L,下游各形态磷浓度除DOP外均高于出水浓度。大沽排污河的总磷浓度变化范围为0.60~6.26 mg/L,均值为1.82 mg/L。其他外源磷输入对大沽排污河磷形态及浓度影响大于污水厂。     

土地处理系统表层土壤中磷赋存形态及其转化过程

以在江淮地区典型经济欠发达村镇(忠庙)构建的化粪池-土地处理系统为对象,研究了土地处理系统表层土壤中磷赋存形态及其转化过程。结果表明,土地处理系统表层土壤中TP含量在149.2～159.4 mg/kg之间,且在运行实验后其含量有所增加。在磷赋存形态方面,Ca-P占TP含量的百分比最高,达到33.1%,随后依次为Ex-P、Org-P、Fe-P和Oc-P,分别为26.1%、19.6%、14.2%和7.0%;在磷活性方面,活性磷(Ex-P和Fe-P)占TP含量的百分比较大,在运行实验后由38.0%增至40.3%,可能是由于惰性磷(Oc-P、Ca-P和Org-P)转化所致,而Org-P矿化速率大于其累积速率。相关性分析表明,除Ca-P外,其他各形态磷均与土壤pH不相关,而Org-P与OM、TP、Ex-P和Ca-P均呈正相关。     

三垟湿地沉积物-间隙水-上覆水界面磷形态研究

沉积物与上覆水间营养物质交换,成为导致水体发生富营养化的首要化学变迁过程.分别在三垟湿地的柑橘林(S1)、景观用地(S2)和生活用地(S3)取样,研究了沉积物-间隙水-上覆水界面磷形态以及相互关系.结果表明:(1)沉积物TP增加时,间隙水PO3-4和可溶性总磷(TDP)也增加.要削减磷在上覆水中的含量,控制间隙水PO3-4或TDP是一良策.(2)随着沉积物铁磷、铝磷的增加,间隙水PO3-4也增加.在三垟湿地沉积物中,铁磷和铝磷含量都可作为间隙水PO34-含量的指示.(3)S1、S2和S3的沉积物活性磷、间隙水TDP和上覆水TDP存在明显的浓度梯度,沉积物活性磷＞间隙水TDP＞上覆水TDP.说明在三垟湿地中,沉积物活性磷是磷释放的关键因子,而沉积物-间隙水界面则是磷释放的关键界面.     

Influences of sediment properties and macrophytes on phosphorous speciation in the intertidal marsh

Phosphorus (P) in wetlands is mainly bound to sediment in various species, which is essential to predict water column P levels. The purpose of this work is to understand the influences of sediment properties and vegetation types on P speciation. Sediments under four vegetation types in the tidal flat and offshore sandbar in Hangzhou Bay of China were collected seasonally. The rank order of P species in sediment based on concentration was exchangeable P (Exch-P)?相似文献   

合肥市南淝河不同排口表层沉积物磷形态分布特征

对合肥市南淝河不同排口处表层沉积物进行了采样,并采用修正后的标准测试程序SMT和钼锑抗紫外分光光度法测定了其中的总磷(TP)、无机磷(IP)、有机磷(OP)、铁/铝磷(Fe/Al-P)和钙磷(Ca-P),同时分析了各形态磷之间以及与沉积物有机质之间的相关性。结果表明,由于各排口附近不同的水动力条件,污染状况以及沉积环境,各排口表层沉积物总磷(TP)的质量分数存在显著差异,其值在771.23~3 065.36 mg/kg之间,除二里河排口(S15)沉积物磷以钙磷(CaP)为主外,其他采样点表层沉积物磷均以铁/铝磷(Fe/Al-P)为主,各形态P的最低值均在位于南淝河上游的S4点,TP、IP、Fe/Al-P的最大值均出现在位于望塘污水厂排口下游60 m处的S6点,潜在释放磷比例最大值在南淝河上游受农业面源污染影响较大的S3点。沉积物各形态磷之间存在着不同程度的相关性,各形态磷与有机质存在着显著的正相关。以上结果表明,南淝河沉积物磷形态分布特征受排口类型影响显著,其中城市污水处理厂尾水可能是受纳水体沉积物重要的磷源。     

Characteristics of phosphorus components in surface sediments from a Chinese shallow eutrophic lake (Lake Taihu): new insights from chemical extraction and <Superscript>31</Superscript>P NMR spectroscopy

As a primary factor responsible for lake eutrophication, a deeper understanding of the phosphorus (P) composition and its turnover in sediment is urgently needed. In this study, P species in surface sediments from a Chinese large eutrophic lake (Lake Taihu) were characterized by traditional fractionation and ³¹P nuclear magnetic resonance (NMR) spectroscopy, and their contributions to the overlying water were also discussed. Fractionation results show that NaOH-P predominated in the algal-dominated zone, accounting for 60.1% to total P in Zhushan Bay. Whereas, refractory fractions including HCl-P and residual-P were the main P burial phases in the macrophyte-dominated zone, the center and lakeshore. Recovery rates of the total P and organic P were greatly improved by using a modified single-step extraction of NaOH-EDTA, ranging from 22.6 to 66.1% and from 15.0 to 54.0%. Ortho-P, monoester-P, and pyro-P are identified as the major P components in the NaOH-EDTA extracts by ³¹P NMR analysis. Trace amount of DNA-P appeared only in sediments from algal- and macrophyte-dominated zones, ascribing to its biological origin. The relative content of ortho-P is the highest in the algal-dominated zone, while the biogenic P including ester-P and pyro-P is the highest in the macrophyte-dominated zone. Moreover, ortho-P and pyro-P correlated positively with TP and chlorophyll a in the overlying water, whereas only significant relationships were found between monoester-P, biogenic P, and chlorophyll a. These discrepancies imply that inorganic P, mainly ortho-P, plays a vital role in sustaining the trophic level of water body and algal bloom, while biogenic P makes a minor contribution to phytoplankton growth. This conclusion was supported by the results of high proportion of biogenic P in algae, aquatic macrophytes, and suspended particulate from the published literature. This study has significant implication for better understanding of the biogeochemical cycling of endogenous P and its role in affecting lake eutrophication.     

Phosphorus fractions and the effect of pH on the phosphorus release of the sediments from different trophic areas in Taihu Lake, China

The sediment characteristics, different phosphorus (P) fraction concentrations and the effect of pH on P release were investigated in a shallow eutrophic lake in China. The total phosphorus (TP) concentrations in the sediments ranged greatly from 420 to 3408 mg kg(-1) and inorganic P (IP) was the main P fraction. For the heavily eutrophic sediment, IP mainly consisted of NaOH-P; while for the mesotrophic sediments, IP mainly consisted of HCl-P. The rate of P release decreased as pH increased from 2 to 6. But it increased as pH increased from 8 to 12. It is suggested that high pH promoted the release of NaOH-P, and low pH promoted the release of HCl-P, and there was no P release occurring in the neutral condition.     

城市富营养化水体底泥净化磷效果

以城市富营养化水体底泥和上覆水为材料,研究了扰动状态下底泥对外源磷的净化效果。结果表明,扰动状态下,200 g湿底泥从上覆水中共吸收外源磷19.92 mg,而静止状态下,200 g湿底泥仅吸收了13.61 mg。然而,厌氧状态下,前者内源磷释放量仅占吸收磷量的43%,而后者则高达63.4%。说明底泥扰动不仅强化了底泥对外源磷的吸收,而且也强化了内源磷的固定能力。这与扰动状态下外源磷在不同形态磷间的数量分布有关。底泥扰动和静止状态下,难释放态磷(HCl-P、闭蓄态Fe/Al-P)的增加量分别占底泥吸收外源磷量的36%和21%。     

Phosphorus mass balance and input load estimation from the wet and dry periods in tropical semiarid reservoirs

The dynamics of total phosphorus (TP) in 18 strategic reservoirs of the high-density reservoir network of the Brazilian semiarid was evaluated during the wet and dry periods for the past 12 years. Seasonal overlying concentrations presented no significant differences for about 90% of the reservoirs (p>0.05). This was attributed to a trade-off between the hydrological/limnological processes occurring in the two seasons. Then, a transient complete-mix mass balance model was applied with particular adaptations for the tropical semiarid reservoirs to estimate the TP load for each season. Because of the relatively well-mixed conditions and high hypolimnetic dissolved oxygen concentrations during the wet season, the wet load was assumed to represent the external TP load. On the other hand, because of the absence of reservoir inflow during the dry season, phosphorus release under anoxic sediment conditions and wind-induced resuspension under shallow water depths, the dry load was assumed to reflect the internal TP load. The maximum external loads were related to peak inflows, notably after drought periods. Consistently, the largest internal loads were obtained during the drought periods, when the reservoirs were shallower and more prone to phosphorus release and resuspension. By comparing the impact of the two input load types, the wet period load was predominant in 72% of the reservoirs. The areal phosphorus loads ranged from 0.66 to 7.29 gP m² year^?1, which were consistent with the literature, despite the very high density of reservoirs. Finally, power-law curves including data for all studied reservoirs were adjusted between the dry period load and volume, dry and wet period loads, wet period load and inflow, and total load and catchment area, resulting in satisfactory R² (0.84–0.98).

     

组合型生态浮床对水体修复及植物氮磷吸收能力研究

在天鹅湖水体中构建以水生植物和陆生喜水植物为实验植物,浮法控制器、水循环增氧系统和造浪-输送系统相集合的组合型生态浮床。在中试研究中,研究了其对天鹅湖上覆水和沉积物中营养物质的修复动态。结果表明,经过4个多月的组合型生态浮床生态修复,天鹅湖上覆水中TN、NH4+-N和TP的去除率分别达到61.92%、63.09%和80.0%,沉积物中TN和NH4+-N含量的去除率分别达到23.79%和37.04%,TP含量升高了43.71%;组合型生态浮床的5种浮床植物的氮磷累积量差异显著,再力花和美人蕉对氮磷的吸收速率显著高于菖蒲、薄荷和水稻,再力花和美人蕉对氮的吸收速率达到12.19 g/(m2.d)和7.90 g/(m2.d),对磷吸收分别达到0.81 g/(m2.d)和0.99 g/(m2.d)。美人蕉和再力花对氮磷的吸收量均是茎叶>根系,其中美人蕉茎叶氮、磷吸收量分别为根系的2.73倍和1.93倍,再力花分别为1.83倍和1.19倍,通过浮床系统植物水上部分的收割可以去除水体中的氮磷。     

底泥扰动状态下内源磷释放过程模拟研究

为了揭示底泥扰动对内源磷释放的影响,通过室内实验模拟了底泥多次扰动状态的整个过程。结果表明,底泥扰动刚结束(0 h),溶解态磷(DIP、DTP)显著降低;底泥扰动结束后(1、6和24 h),溶解态磷发生"滞后释放"。第1 d,在1、6和24 h采样时段,DIP、DTP的"滞后释放量"最大,分别达到20.0 1mg/kg,22.12 mg/kg,16.85 mg/kg和17.21 mg/kg,22.12 mg/kg,9.69 mg/kg。第2 d,该释放量分别降低了44.80%~57.87%和42.52%~61.24%。随着底泥扰动次数的增加,溶解态磷的"滞后释放"逐渐转变为"负释放",同时,DIP/TP和DTP/TP逐渐降低。这说明,底泥扰动应该是促进了上覆水中溶解态磷向底泥的迁移和强化了底泥对磷的固定作用,同时降低了水体中磷的可生物利用性。因此推测,底泥扰动延缓了水体富营养化的发展进程。