大鹏湾海水中氮和磷的分布变化     

周毅频  李绪录  夏华永 《广东海洋大学学报》2011,31(3)

依据香港特别行政区环境保护署于1999—2007年106个航次的调查资料,结合国家海洋局南海分局于1998—2007年10个航次的调查资料,简要描述和分析大鹏湾海水中可溶性无机氮(DIN)和可溶性无机磷(DIP)含量的多年平均分布变化。结果表明,DIN和DIP含量均夏、冬季较高,而春、秋季较低;受香港和深圳等陆源排放影响,四季吐露港西部和沙头角海区域的DIN和DIP含量普遍比其他区域高;夏季南澳养殖场附近水域的DIN也明显较高,可能与养殖场的饵料投放有关。大鹏湾海水中平均氮磷原子比大于16,而DIN和DIP的平均含量分别为0.069和0.009 mg/L。夏季,由于外海高盐水的入侵,底层水中DIN和DIP含量明显高于表层。9 a调查期间,大鹏湾香港海区海水中DIN和DIP含量的年际变化呈较明显下降趋势,而氮磷原子比的年际变化则呈上升趋势。  相似文献   

南方典型灌区农田地表径流氮磷流失特性   总被引：4，自引：0，他引：4  

洪林  李瑞鸿 《地理研究》2011,30(1):115-124

农田地表径流氮磷流失与土地利用、土壤和灌溉方式有着极为重要的联系,而且具有十分明显的地域特点。本文选取我国南方丘陵地区典型灌区——湖北省漳河灌区的水旱作物(分别为水稻和玉米)作为研究对象,开展了农田地表径流N素和P素流失特性及其影响因素的试验研究。结果表明:土地利用类型对地表N素流失量的影响显著,地表TN流失量表现为旱地>水田;土地利用类型对地表P素的流失量有较大影响,但差异性未达到显著水平,地表TP流失量表现为水田>旱地。随着降雨强度的增大,铵态氮和硝态氮浓度均呈减小的趋势,有机氮的比例由3.2%增至69.7%,无机氮比例由96.8%降至30.3%,更多的有机氮随地表径流流失;随着降雨强度的增大,农田排水总磷和磷酸磷也呈增加的趋势。采用节水灌溉方式,降雨利用率提高了14%~23%,节水率达15%,降雨排水量减少20~25 mm左右,能够有效降低农田氮、磷等养分流失对地表水的污染。作物生育期和地形地势差异也会影响降雨径流特征和农田养分流失。  相似文献   

工业膨胀蛭石对水体中磷的去除研究     

金诗迪  秦文莉  夏枚生  叶瑛  韩兵男 《岩石矿物学杂志》2014,33(2):377-384

研究了工业膨胀蛭石对模拟养殖废水中磷酸盐的吸附性能,考察了pH值、吸附时间、固液比对吸附效果的影响,并通过原子吸收光谱法测定了蛭石在对磷酸盐吸附过程中主要金属元素的浸出含量,探究膨胀蛭石吸附水中磷的吸附平衡,对吸附机理进行了探讨。结果表明,工业膨胀蛭石对磷酸盐的吸附量可达2.76 mg/g,pH值在3~9的范围内有较高的吸附量;K、Ca、Mg这3种元素的浸出含量随着溶液中磷酸盐浓度升高而增加,Fe、Al元素则相应减少;工业膨胀蛭石对磷的吸附机理主要是先通过离子交换作用交换出层间阳离子,然后与H2PO-4、HPO2-4反应形成沉淀被吸附;吸附等温曲线均符合Freundlich公式与Langmuir公式,相关系数分别为0.978 1和0.985 1。  相似文献   

基于Mark5B＋GPU脉冲星观测系统     

李佳功  徐永华  李志玄  汪敏  季凯帆 《天文研究与技术》2014,(4):335-342

云南天文台40m射电望远镜进行的脉冲星观测数据量巨大,必须实现数据的实时处理,否则将会产生海量的数据积压.为实现这一目标,采用图形处理器架构,对Mark5B数据进行解码、消色散、折叠等处理.实验结果表明,对以1s8MB的实时采样,可以在0.51s内处理完成,从而实现了实时处理的要求.首先介绍这一观测系统各部分的图形处理器实现,然后相对于传统中央处理器构架,对各部分的运算速度进行了详细的对比.针对时间开销最大的消色散部分,分析了单次傅里叶变换的数据量大小对执行效率的影响.从系统最终的输出轮廓和柱状图上可以看到实时处理的结果符合要求.最后对存在的问题和未来的工作进行了讨论.  相似文献   

湖泊沉积物中磷形态标准物质研制   总被引：6，自引：6，他引：0  

袁建  王亚平  许春雪 《岩矿测试》2014,33(6):857-862

水体富营养化与沉积物中磷元素的形态有密切关系。为了准确测定沉积物中不同形态的磷的含量,欧盟在2000年研制了第一个湖泊沉积物中磷形态标准物质(BCR 684),但基本用尽已不能满足需求,而且该标准物质采集于欧洲某湖泊,沉积物类型及污染情况与我国湖泊不相匹配。本文结合我国沉积物的类型和湖泊污染状况,研制了我国首批2个湖泊沉积物中磷形态标准物质(编号为 GBW 07462和GBW 07463)。候选物样品采集地点为江苏太湖和湖南洞庭湖,样品经过自然干燥、研磨、灭菌、陈化等加工处理,随机抽取15个子样采用单因素方差分析(F检验法)进行均匀性检验,检验的F实测值均小于临界值,表明样品均匀性良好。根据ISO导则35推荐方法对候选物样品在一年内进行四次稳定性检查,分析结果无方向性变化,再通过2次验证实验,样品稳定性良好。此批磷形态标准物质采用8家实验室联合定值,定值参数包括五种磷形态:总磷、无机磷、有机磷、磷灰石态磷、非磷灰石态磷;磷形态提取方法采用欧盟SMT法,测定方法采用钼锑钪光度法和电感耦合等离子体发射光谱法(实验过程中用欧盟BCR 684作为质量监控);按照《一级标准物质研制规范》(JJG 1006—1994)和ISO导则35的要求给出了五种磷形态的标准值和不确定度。此批磷形态标准物质样品代表了我国典型富营养化湖泊的沉积物类型,采样点的区域代表性强,定值项目选择合理、量值准确,可应用于环境、地质、农业、地球化学等研究领域沉积物的磷形态样品质量监控。  相似文献   

黄河三角洲新生湿地磷分布特征及吸附解吸规律   总被引：3，自引：0，他引：3  

孙军娜  徐刚  邵宏波 《地球化学》2014,(4):346-351

采用改进的 Hedley 磷分级方法研究了黄河三角洲新生湿地由河向海过渡带表层土壤磷形态变化和分布特征,并通过等温吸附解吸实验阐明了沿程土壤对外源磷的持留能力和释放风险。结果表明,各样点无机磷占总磷93%以上,是磷的主要存在形态。土壤中有机磷含量较低,可能与较低的有机质含量有关。无机磷中稀盐酸磷是最主要存在形态,与各样点Ca/Al含量密切相关。有效磷含量在18.6~33.4 mg/kg之间,仅占总磷的3.2%~5.9%,可能会限制湿地植物的生长。覆有植被的土壤中有效磷含量显著高于河滩和海滩土壤,说明植被存在对有效磷的积累有一定促进作用。由吸附解吸实验可知,加入较低浓度（0.05~5 mg/L）的外源磷时,随着初始磷浓度的升高,土壤对磷的吸附量增加,吸附率为70%~99%,解吸率小于7%,这说明各样点土壤的除磷能力较强,且流失风险较低。  相似文献   

Influence of the hyporheic zone on the phosphorus dynamics of a large gravel‐bed river,Garonne River,France     

Philippe Vervier  Sonia Bonvallet‐Garay  Sabine Sauvage  H. Maurice Valett  José‐Miguel Sanchez‐Perez 《水文研究》2009,23(12):1801-1812

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   

AVAILABILITY OF PHOSPHORUS FROM SELECTED INORGANIC PHOSPHATES TO JUVENILE ABALONE, HALIOTIS DISCUS HANNAI INO   总被引：2，自引：0，他引：2  

Tan Bei-ping  Mai Kang-sen  Xu Wei 《中国海洋湖沼学报》2002,20(2):118-128

The availability of phosphorus to juvenile abalone,Haliotis discus hannai from primary, secondary and tertiary calcium phosphate, primary sodium or potassium phosphate separately or in combination was determined in a 120-day feeding trial. Seven semi-purified diets were formulated to contain relatively constant dietary phosphorus, ranging from 0.78%–0.82%. The concentrations of dietary phosphorus were presumed to be slightly below the requirement for abalone. A brown alga,Laminaria japonica, was used as a control diet. Abalone juveniles of silimar size (average weight 1.18 g; average shell length 18.74 mm) were distributed in a single-pass, flow-through system using a completely randomized design with eight treatments and three replicates each treatment. The survival ranged from 71.1% to 81.1%, and was not significantly (P>0.05) related to dietary treatment. However, the weight gain rate (41.72%–65.02%), daily increment in shell length (36.87–55.07 μm) and muscle RNA-DNA ratio (3.44–4.69) were significantly (P<0.05) affected by dietary treatment. Soft body alkaline phosphatase activity (10.9–19.8 U/g wet tissue) and carcass levels of lipid (7.71%–9.33%) and protein (46.68%–49.35%) were significantly (P<0.05) responsive to available phosphorus of the diets. Dietary treatment had significant effect (P<0.05) on concentrations of phosphorus in the whole body (WB) and soft body (SB). Apparent digestibility coefficients (45%–97%) of phosphorus were also significantly (P<0.05) different between dietary treatments. The results indicated that among these inorganic compounds, primary calcium, potassium and sodium phosphates separately or in combination could be utilized effectively by juvenile abalone as dietary phosphorus sources (availability ranging from 87%–97%). However, secondary and tertiary calcium phosphates were found to be low in availability, the values being 45% and 77%, repectively. Project 39670572 supported by the Natural Science Foundation of China (NSFC).  相似文献   

激光热透镜法测定水中痕量磷的研究     

杨胜科  朱小雲  阎宏涛 《地球科学与环境学报》1996,(1)

本文采用激光热透镜分析法测定水中痕量磷．研究并讨论了测定磷的各种影响因素，并与分光光度法进行比较．结果表明，热透镜分析方法比分光光度法具有较高的灵敏度．其线性范围为２～６０ｎｇＰ／ｍＬ，方法检出限为０．４ｎｇＰ／ｍＬ．用于雨水及地下水中痕量磷测定，结果满意．  相似文献   

Multiple objective evaluation of a simple phosphorus transfer model     

Russell M. S. Smith  Howard S. Wheater 《水文研究》2004,18(9):1703-1720

A simple phosphorus (P) transfer model of the Welland catchment, UK, is evaluated against multiple objective functions using a Monte Carlo approach that combines calibration, identifiability, sensitivity and uncertainty analysis. The model is based on simple conceptual rainfall‐runoff and river routing components, combined with estimates of the daily non‐point source load derived from annual landuse‐based export coefficients, disaggregated as a function of the runoff. The model has limited data requirements, consistent with data availability, and is parsimoneous with respect to the number of parameters identified through inverse modelling. The best performing parameter sets capture the main aspects of the observed flow and total P (TP) concentrations and provide a suitable basis for a decision‐support tool. However, a trade‐off is evident between matching the observed flow peaks, flow recessions and TP concentrations simultaneously, highlighting some limitations of the model structure and/or calibration data. Model analysis indicates that daily non‐point source load cannot be described as a function of near‐surface runoff and land use alone, but that other influences, including seasonality, are important. However, further model development to improve performance is likely to introduce additional complexity (in terms of parameter numbers), and hence additional problems of parameter identifiability and output uncertainty, which in turn raises issues of the information content of the available data. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献