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1.
太湖大气氮、磷营养元素干湿沉降率研究   总被引:19,自引:0,他引:19       下载免费PDF全文
分析了2002年7月—2003年6月太湖周边地区太湖站、拖山岛、东山站、无锡、苏州、湖州、常州、金坛等8个站、点大气TN、TP沉降通量和降水化学组成观测资料,测定和计算了水气界面TN、TP的表观总沉降率(RT)、湿沉降率(RW)和干沉降率(RD)。太湖大气TN的年平均RT为4226kg/(km2.a),TP的年平均RT为306kg/(km2.a)。大气TN、TP的年沉降负荷分别占由环湖河道等点污染源输入的N、P总负荷的48.8%和46.2%。指出形成太湖大气TN污染的主要途径是湿沉降,而大气TP污染则主要来自气溶胶等固体物质的干沉降;小雨携带入湖的大气TN、TP污染物通量高于中雨和大雨。TN总沉降率曲线在春季3—5月出现高峰值的现象对太湖水体的富营养化具有潜在的促进影响。  相似文献   

2.
惠州大亚湾春夏季大气氮磷沉降的研究   总被引:2,自引:0,他引:2  
通过对惠州大亚湾春夏季大气沉降的采样分析,探讨了大亚湾大气干湿沉降中氮磷营养盐的特征。结果表明,观测期间总氮和总磷的月均沉降通量分别为257.45和1.79kg·km-2·月-1,均以湿沉降为主。氮的干湿沉降都表现出了明显的春夏季变化差异,干沉降通量夏季比春季大,而湿沉降的结果与此相反;磷的干湿沉降在两季的观测结果均趋于稳定,无明显变化。在降雨冲刷、季风气候引起的大气传输和局部污染的共同作用下,大亚湾大气中的营养盐主要以NO3--N的形式存在。大亚湾大气中的氮盐是该地区大气污染的主要控制目标。  相似文献   

3.
为研究海水养殖对海湾沉积物的累积影响, 对大亚湾的大鹏澳养殖区沉积物柱状样中总氮、总磷和有机碳的含量及剖面分布特征进行了研究, 并探讨了海水养殖区沉积物中氮、磷的污染状况。结果表明, 网箱养殖区、贝类养殖区和对照区等3个区域柱状样中总氮的含量范围分别为638.2—3803.9mg.kg-1、740.9—2152.1mg.kg-1和343.2—471.9mg.kg-1, 总磷的含量范围分别为344.7—3233.9mg.kg-1、297.9—497.5mg.kg-1和650.2—1327.2 mg.kg-1, 有机碳的含量范围分别为0.96%—2.22%、0.87%—1.13%和0.69%—0.95%。该三个因子的含量均从底层至表层呈增加趋势, 但网箱养殖区上层增加幅度最为剧烈, 贝类区次之, 对照区变化幅度最小。所有柱状样中, 总氮含量均超标, 但网箱养殖区总氮污染最为严重, 贝类养殖区次之, 对照区最轻; 网箱养殖区的总磷在上层的不同深度超标, 而贝类养殖区及对照区柱状样的总磷含量均未超标。  相似文献   

4.
广东沿海新发现的海草床   总被引:2,自引:0,他引:2       下载免费PDF全文
通过对广东沿海水域的现场调查, 新发现8个海草床, 主要分布在柘林湾、汕尾白沙湖、惠东考洲洋、大亚湾、珠海唐家湾、上川岛、下川岛和雷州企水湾。海草种类主要包括喜盐草(Halophila ovalis)、贝克喜盐草(Halophila beccarii)和矮大叶藻(Zostera japonica)等3种。海草覆盖率为6.67%—53.33%, 茎枝密度为3 428.57— 10 542.00shoots.m-2, 生物量为12.86—118.24g.m-2。海草床底上生物密度为16.67—734.67ind.m-2, 生物量为15.39—426.88g.m-2, 多样性指数为0.46—1.98, 均匀度指数为0.28—0.89。海草床生境受到的严重威胁主要来自围海养殖(养蚝、养螺)、污水排放、渔民作业方式(电鱼、电虾、扒螺、挖贝类)、自然灾害(台风和洪水)等。  相似文献   

5.
南澳岛是广东南澳县的主岛, 周边海域的环境保护被置于当地社会经济发展的重要位置。为此, 2004年 5月、7月选择以水产养殖为主的后江湾和白沙湾及以旅游为主的青澳湾作为研究对象, 对南澳岛海域重金属的 含量、分布、富集及污染状况进行了调查与评价。结果表明该海域重金属元素的平均含量为Cd: 0.19mg.kg-1, Cr: 26.86mg.kg-1, Cu: 20.71mg.kg-1, Ni: 22.78mg.kg-1, Pb: 35.67mg.kg-1, Zn: 79.48mg.kg-1, 低于近岸经济发达海域, 但高于受人类活动影响较小的外海; 在分布特征上表现为湾口高于湾内, 养殖区高于非养殖区的总趋势, 但在各海湾之间重金属含量并无显著差异, 表明南澳岛海域重金属主要来源于地表径流输入。该海域以城市污水中代表元素Cu (Cf = 2.75), Pb (Cf = 2.27)富集为主; 以海洋沉积物质量标准、沉积物质量基准和美国太平洋沿岸基线值评价, 南澳岛海域环境质量均处于健康状态, 但其潜在污染效应仍值得关注。  相似文献   

6.
采用衍生化处理和气相色谱-质谱联用分析方法, 测定了珠江口及其以东近海海域表层海水中的三氟乙酸(Trifluoroacetic acid, TFA)含量。珠江口及其以东近岸的红海湾和大亚湾海区TFA浓度范围分别为113—170ng.L–1和202—336ng.L–1。红海湾内海水中TFA的平均水平(279ng.L–1)明显高于外海海水(210ng.L–1), 说明港湾内或其周边地区可能有TFA的点源输入。此外, 外海海水中TFA平均浓度比珠江口高69.1ng.L–1, 表明这种亲水性强、稳定性高的化合物除了已知的人为来源外, 可能还存在未知的人为源或自然源, 使得海洋作为其最终的汇浓度不断累积。  相似文献   

7.
珠江河口咸潮期间浮游植物的群落特征   总被引:4,自引:0,他引:4       下载免费PDF全文
根据2007年底至2008年初珠江河口咸潮入侵期间大潮和小潮的两次调查资料, 对浮游植物的种类组成、种数和细胞密度的分布等群落特征进行了分析, 并探讨环境因素对浮游植物群落的影响。共鉴定浮游植物76种, 包括38种硅藻、18种绿藻、14种甲藻、4种蓝藻和2种裸藻。浮游植物种数分布有明显的空间变化, 一般从河口上段至下段种数减少; 大潮时浮游植物的种数低于小潮时, 并且各水层之间浮游植物种数分布不均匀。优势种以淡水硅藻为主, 如颗粒直链藻Melosira granulata、颗粒直链藻最窄变种 Melosira granulata v. angustissima、小环藻 Cyclotella sp.和海链藻Thalassiosira sp.等; 河口上段的站优势种突出, 密度分布不均匀, 均匀度值比较低。大潮和小潮期间浮游植物细胞密度的平均值分别为53.80×104个.L-1和62.21×104个.L-1, 变化范围为(1.48— 290.41)×104个-L-1和(1.52—283.62)×104个.L-1; 二者的平面分布趋势基本相同, 由河口上段至下段呈递减的格局; 硅藻类的细胞密度占明显优势。浮游植物的种类组成、种数和细胞密度的分布受盐度、营养盐等环境因子的影响, 并且具有明显的潮周期性。  相似文献   

8.
本文于2011年8月连续采集了青岛近岸大气气溶胶TSP(总悬浮颗粒物)样品,运用离子色谱法(IC)测定了可溶性无机氮磷组分的浓度,并估算了其干沉降通量,分析了天气过程对无机氮磷浓度的影响,讨论了大气干沉降对黄海初级生产力的影响。结果表明,夏季青岛沿海地区气溶胶颗粒物、NH+4-N、NO-3-N的平均浓度分别为139.96、9.70、3.08μg/m3,NO-2-N和PO3-4浓度很低,分别在0.15和1.00μg/m3以下;NH+4-N含量约为NO-3-N的3倍,二者之和占总无机氮的99%以上。天气过程显著影响颗粒物及无机氮的浓度和组成,雾天时,颗粒物、NH+4-N、NO-3-N的浓度分别升高到晴天时的1.48、1.98和2.21倍,大风天气下分别为晴天时的1.85、2.84和4.50倍;降雨对气溶胶存在明显的清除作用,对颗粒物和无机氮的清除率分别为7.70%~32.97%和54.16%~64.49%。气象要素和气团来源、路径对气溶胶浓度和组成的影响也十分显著。颗粒态无机氮磷的沉降通量分别为0.55和96.14μg/(m2·d),输入黄海后可产生94.51~138.30mg/(m2·month)的新生产力,对总初级生产力的贡献不大,但特殊天气下大气干沉降引起的新生产力可以在短时间内迅速增加。颗粒态无机氮磷的沉降通量之比为13.7,沉降后不会使黄海磷限制的营养盐结构产生明显变化。  相似文献   

9.
大通湖是湖南省面积最大的淡水养殖湖泊,冬季作为捕鱼的旺季并且水位较低,水体和表面沉积物中氮、磷容易受到渔业生产的影响。本文从地统计学出发,通过研究冬季大通湖水体和沉积物中有机质(OM)、氮(N)和磷(P)的空间结构特征及其耦合关系,探讨大通湖富营养化程度及其影响因素,为可持续水产养殖和生态修复提供科学依据。结果表明:冬季大通湖水体中总氮(TN)、总磷(TP)浓度较高,平均值分别达到了3.78mg/L和0.29mg/L,为劣Ⅴ类。水体中NH_4~+含量相对较低,平均为0.17mg/L,属于地表水Ⅱ类。与2011年数据比较,沉积物中TP浓度较高,平均升高到了1469mg/kg;而沉积物TN基本持平,平均为1224mg/kg;沉积物TP和水NO_3~-的"块金值/基台值"分别为43.4%和34.5%,表现为中等空间相关性(spatial dependence),其他N、P指标的"块金值/基台值"均低于25%,表现为强烈空间相关性。冬季大通湖沉积物OM、TN和TP在空间上呈现出有规律的带状分布,而水体N、P大体上呈现出"品"字形的斑块分布;水体中的氮磷比平均为13.03,比较适合浮游植物生长;沉积物OM只与沉积物TN和TP呈极显著正相关(P0.01),而积物中TN和TP与水体中的TN和TP相关性不显著。因此,大通湖水体修复在控制外源输入的情况下,还应考虑综合的生态系统工程措施。  相似文献   

10.
中国东部海域大气气溶胶入海通量的研究   总被引:18,自引:2,他引:16  
刘毅  周明煜 《海洋学报》1999,21(5):38-45
根据中国东部海域气溶胶浓度及分级采样资料,计算得出黄海、东海及日本以南海域沙尘气溶胶的代表元素铝(Al)每月干沉降通量分别为42.8、18.3、5.2mg/m2;其中各海域春季的干沉降通量均占全年干沉降通量的40%以上.相应每月总沉降通量分别为54.1、29.8、10.5mg/m2.渤海、黄海、东海及日本以南海域每年沙尘气溶胶总沉降通量分别为26.4、9.3、5.1、1.8g/m2.东海污染元素总沉降通量以春季最大,夏、秋季次之,冬季最小.日本以南海域锑(Sb)元素总沉降通量的季节分布为冬季最大,夏、秋季次之,秋季最小;硒(Se)元素总沉降通量的最大值出现在夏季,其他季节分布比较均匀.  相似文献   

11.
Nitrogen and phosphorus contents are analyzed in the overlying waters and pore waters taken from the Changjiang Estuary and Shanghai coastal tidal flats in this study. In addition, the diffusion fluxes of nitrogen and phosphorus across the sediment-water interface in tidal flats are estimated according to the nutrient concentration gradients at the interface. It has been indicated that the concentrations of ammonium, nitrite, nitrate and dissolved phosphorus in overlying waters range from 0.0082~2.56, 0.03~0.58, 0.69~5.38 and 0.035~0.53 mg/L, respectively, while 0.0025 ~ 1.35 mg/L for NH4+-N, 0. 0055 ~ 0.20mg/L for NO2--N, 0.61~1.14 mg/L for NO3--N and 0.11~0.53mg/L for DP insurface pore waters.The findings have revealed that ammonium, nitrite, nitrate and dissolved phosphorus diffusion fluxes across the sediment-water interface are between -0.024~0.99, -0.39~ -0.0019, -3.09~the source of phosphorus and an important sink for nitrogen in the waters.  相似文献   

12.
Flow-through flumes were used to quantify net areal fluxes of nutrients in the fringe mangrove zone of lower Taylor River in the southern Everglades National Park. We also quantified net areal fluxes along the open water portion of the channel to determine the relative importance of either zone (vegetated vs. unvegetated) in the regulation of nutrient exchange in this system. Taylor River's hydrology is driven mainly by precipitation and wind, as there is little influence of tide. Therefore, quarterly samplings of the vegetated and unvegetated flumes were slated to include typical wet season and dry season periods, as well as between seasons, over a duration of two years. Concentrations of dissolved and total organic carbon (DOC and TOC) were highest during the wet season and similar to one another throughout the study, reflecting the low particulate loads in this creek. Dissolved inorganic nitrogen (nitrate+nitrite+ammonium) was 10–15% of the total nitrogen (TN) content, with NO−x and NH+4 showing similar concentration ranges over the 2-year study. Soluble reactive phosphorus (SRP) was usually <0·05μM, while total phosphorus (TP) was typically an order of magnitude higher. Net areal fluxes were calculated from nutrient concentration change over the length of the flumes. Most flux occurred in the vegetated zone. Dissolved inorganic nitrogen and DOC were usually taken up from the water column; however, we saw no seasonal pattern for any constituent over the course of this study. Total nutrients (TOC, TN, and TP) showed little net exchange and, like SRP, had fluxes that shifted irregularly throughout the study. Despite the lack of a clear seasonal pattern, there was a great deal of consistency between vegetated flumes, especially for NO−x and NH+4, and fluxes in the vegetated flumes were generally in the same direction (import, export, or no net flux) during a given sampling. These findings suggest that the fringe mangrove zone is of considerable importance in regulating nutrient dynamics in lower Taylor River. Furthermore, the influence of this zone may at times extend into northeast Florida Bay, as the bay is the primary recipient of water and nutrients during the wet season.  相似文献   

13.
通过2009年10月—2010年7月对深圳大亚湾大鹏澳网箱养殖区、网箱外0.5km(对照区1)和网箱外2km(对照区2)等3个区域的现场调查,阐明了海水中温度、盐度、pH、溶解氧(dissolved oxygen,DO),化学需氧量(chemical oxygen demand,CODMn)、叶绿素a(Chl a)和营养盐等水质因子的时空分布特征及相关性,并评价了海区的营养状态。结果表明,与两个对照区域相比较,大鹏澳网箱养殖对海水中的CODMn、Chl a和SiO3-Si的影响不明显,对DO、pH、PO4-P、NO2-N、NH4-N、总氮(total nitrogen,TN)和总磷(total phosphorus,TP)的影响相对较大,其中对NH4-N的影响已经扩散到了网箱外0.5km区域。网箱养殖区在冬季和春季是中营养水平,而夏季则是富营养水平。总体来说,大鹏澳网箱养殖区水质有恶化的趋势,必须采取一定的有效措施对网箱区环境进行合理调控。  相似文献   

14.
Tomogashima Strait, which is an entrance of Osaka Bay, is a very important area for material transport because a large volume of pollutant-rich water in Osaka Bay is transported through this strait. We have investigated the cross sectional structures of current and material fluxes at Tomogashima Strait, Osaka Bay. Tidal current and residual flow patterns in cross section at Tomogashima Strait during summer and winter are almost the same, and residual flow in summer is stronger than that in winter. However, the net water exchange through the strait in summer was almost the same volume as that in winter. At Tomogashima Strait, total suspended matter (TSM) and particulate organic carbon (POC), and individual nitrogen and phosphorus compartments in Osaka Bay always flowed out except particulate organic nitrogen (PON). The average outflows of total nitrogen (TN) and total phosphorus (TP) at Tomogashima Strait over a year were calculated to be 145 ton/d and 30 ton/d, respectively. The average outflow of DIN and DIP at Tomogashima Strait over a year were 95 ton/d and 13 ton/d (DIN/DIP = 16), respectively. Residence times of both DIN and DIP in Osaka Bay were estimated to be about two months.  相似文献   

15.
以新型间歇增氧垂直流人工湿地系统为研究对象,采用中心复合设计响应曲面法优化垂直流人工湿地脱氮处理过程中曝气工艺参数并预测其脱氮效能。以曝气量、曝停比、曝停周期为间歇曝气影响因素,分别以人工湿地氨氮去除率和总氮去除率为响应值建立垂直流人工湿地氨氮去除率和总氮去除率的二次回归模型,通过假设检验(F-test),模型均非常显著且具有较好的相关性。间歇增氧垂直流人工湿地脱氮处理中曝气量、曝停比为对氨氮去除影响极显著的曝气参数,通过影响因子主次分析,曝气量、曝停比、曝停周期对氨氮去除率的影响顺序是:曝停比>曝气量>曝停周期;曝停周期为对总氮去除具有极显著影响的曝气参数,通过影响因子主次分析,曝气量、曝停比、曝停周期对TN去除率的影响顺序是:曝停周期>曝气量>曝停比。模型预测氨氮与总氮去除率的最佳曝气参数分别为:曝气量2 m3/h、曝停比0.25、曝停周期12 h、曝气量2 m3/h、曝停比0.25、曝停周期6 h;氨氮、总氮去除率预测值分别为98.4%、83.2%,预测值与实测值吻合。响应曲面法用于优化曝气参数对人工湿地脱氮效能影响具有可行性,可实现间歇增氧人工湿地脱氮效能的准确预测。  相似文献   

16.
池塘循环水养殖与人工湿地相组合,是将养殖生产与净化养殖废水并举的新思路,研究该组合系统中氮、磷物质的源-汇作用,对系统工艺参数的设置具有指导意义。本文研究了在复合垂直潜流人工湿地-池塘循环水养殖系统中氮、磷生源要素的流向与收支,并通过氮、磷收支评价人工湿地对池塘尾水净化效果。研究表明:在5个月的试验周期内,饲料投入是该养殖系统氮、磷收入最主要的途径,分别占总收入的65.61%和81.44%,其次是水体中带入的氮、磷。在试验初期,由于养殖生物与湿地植物的生物量较小,因此其对系统的氮、磷收入部分贡献较小。沉积物蓄积是氮、磷最主要的支出途径,占总支出氮、磷的比例为28.60%和42.23%;其次为养殖生物的收获,占总支出氮、磷的26.05%和30.77%;人工湿地植物与基质蓄积的氮、磷占总支出的15.81%和16.11%;通过池塘底泥渗漏损失的氮、磷较少。人工湿地对氨氮、总氮、总磷的去除率分别为33.72%~66.32%、36.35%~72.40%、44.69%~57.32%,且氨氮与总氮的去除率受温度影响显著。研究结果表明:人工湿地对池塘尾水有显著的净化效果,可通过植物收割、基质移除等方式去除系统内未被有效利用的氮、磷,减少池塘内源性氮、磷的蓄积。人工湿地-池塘循环水养殖模式具有良好的生态效益,是一种绿色、可持续的养殖模式。  相似文献   

17.
Physical and biological processes controlling spatial and temporal variations in material concentration and exchange between the Southern Everglades wetlands and Florida Bay were studied for 2.5 years in three of the five major creek systems draining the watershed. Daily total nitrogen (TN), and total phosphorus (TP) fluxes were measured for 2 years in Taylor River, and ten 10-day intensive studies were conducted in this creek to estimate the seasonal flux of dissolved inorganic nitrogen (N), phosphorus (P), total organic carbon (TOC), and suspended matter. Four 10-day studies were conducted simultaneously in Taylor, McCormick, and Trout Creeks to study the spatial variation in concentration and flux. The annual fluxes of TOC, TN, and TP from the Southern Everglades were estimated from regression equations. The Southern Everglades watershed, a 460-km2 area that includes Taylor Slough and the area south of the C-111 canal, exported 7.1 g C m−2, 0.46 g N m−2, and 0.007 g P m−2, annually. Everglades P flux is three to four orders of magnitude lower than published flux estimates from wetlands influenced by terrigenous sedimentary inputs. These low P flux values reflect both the inherently low P content of Everglades surface water and the efficiency of Everglades carbonate sediments and biota in conserving and recycling this limiting nutrient. The seasonal variation of freshwater input to the watershed was responsible for major temporal variations in N, P, and C export to Florida Bay; approximately 99% of the export occurred during the rainy season. Wind-driven forcing was most important during the later stages of the dry season when low freshwater head coincided with southerly winds, resulting in a net import of water and materials into the wetlands. We also observed an east to west decrease in TN:TP ratio from 212:1 to 127:1. Major spatial gradients in N:P ratios and nutrient concentration and flux among the creek were consistent with the westward decrease in surface water runoff from the P-limited Everglades and increased advection of relatively P-rich Gulf of Mexico (GOM) waters into Florida Bay. Comparison of measured nutrient flux from Everglades surface water inputs from this study with published estimates of other sources of nutrients to Florida Bay (i.e. atmospheric deposition, anthropogenic inputs from the Florida Keys, advection from the GOM) show that Everglades runoff represents only 2% of N inputs and 0.5% of P input to Florida Bay.  相似文献   

18.
郭水伙 《台湾海峡》2009,28(1):71-76
据南海环境调查资料,研究了南海水体NO3-N、NO2-N、NH4-N、DIN含量及无机氮组成的垂直变化规律.结果表明:NO3-N、NO2-N、NH4-N、DIN含量范围和均值分别为0.00~43.9,12.32;0.00~1.69,0.07;0.17-14.87,1.32;0.35~45.92,13.73μmol/dm^3.其含量分布与垂直变化特征与深海、大洋的相似,表明南海水是太平洋的变性水体.NO3-N、DIN含量的垂直分布跃层出现于75~500m间,夏季的跃层强度分别为6.61X10-’、6.68×1012Ixmol/(dm’·m),冬季的均为5.65×10^-2μmol/(dm^3·m);NO2-N含量的最大值多出现于75~100m之间,NH4-N含量的最大值出现在0m层.在浮游植物活动较旺盛的真光层中,NH4-N为无机氮的主要存在形态(平均占比为64.4%).真光层以下NO3-N为无机氮的主要存在形态(平均占比≥90.8%).对三项无机氮含量与其他生源要素、水文因子的相关分析结果表明,NO3-N含量与PO4-P、TDP、TP、SiO3-Si、S均呈显著正相关,与pH、DO、O2%、t则呈显著负相关.  相似文献   

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