太湖西部环湖河道污染物输移速率变化特征   总被引：8，自引：2，他引：6  

朱金格  刘鑫  邓建才  彭俊翔  张海涛 《湖泊科学》2018,30(6):1509-1517

阐明污染物出入湖输移速率对于湖泊陆域污染控制具有重要意义.本文研究了太湖西部主要环湖河道总氮（TN）、溶解性总氮（DTN）、总磷（TP）、溶解性总磷（DTP）和高锰酸盐指数（COD_Mn）输移速率变化特征.结果表明环湖河道上述指标净输入速率分别为707.9、727.0、28.8、18.2和700.9 g/s.城东港、百渎港、大浦港和沙塘港4条河道TN、DTN、TP、DTP和COD_Mn输入速率分别占西部河道总输入速率的62.7%、63.6%、67.1%、66.6%和64.8%.太浦河、长兜港和大钱港TN、DTN、TP、DTP和COD_Mn输出速率占总输出的86.5%、86.9%、85.0%、85.3%和80.6%.污染物净输入速率受水情影响,TN和DTN浓度汛前最大,而TP、DTP、COD_Mn浓度汛期增大,汛后分别降低44.2%、48.8%和39.8%.城东港氮、磷输入速率受浓度控制,其他河道各指标输移速率受流量控制.近岸湖体TN浓度与入湖速率呈显著正相关,而离岸湖体TN、TP、COD_Mn浓度对入湖速率的变化响应不明显.  相似文献   

Nitrous Oxide and Methane Emissions in Spring Maize Field in the Semi‐Arid Regions of Loess Plateau     

《洁净——土壤、空气、水》2017,45(1)

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A coastal three-dimensional water quality model of nitrogen in Jiaozhou Bay linking field experiments with modelling     

Dongliang Lu  Keqiang Li  Shengkang Liang  Guohong Lin  Xiulin Wang 《Marine pollution bulletin》2017,114(1):53-63

With anthropogenic changes, the structure and quantity of nitrogen nutrients have changed in coastal ocean, which has dramatically influenced the water quality. Water quality modeling can contribute to the necessary scientific grounding of coastal management. In this paper, some of the dynamic functions and parameters of nitrogen were calibrated based on coastal field experiments covering the dynamic nitrogen processes in Jiaozhou Bay (JZB), including phytoplankton growth, respiration, and mortality; particulate nitrogen degradation; and dissolved organic nitrogen remineralization. The results of the field experiments and box model simulations showed good agreement (RSD = 20% ± 2% and SI = 0.77 ± 0.04). A three-dimensional water quality model of nitrogen (3DWQMN) in JZB was improved and the dynamic parameters were updated according to field experiments. The 3DWQMN was validated based on observed data from 2012 to 2013, with good agreement (RSD = 27 ± 4%, SI = 0.68 ± 0.06, and K = 0.48 ± 0.04), which testifies to the model's credibility.  相似文献   

鄱阳湖区水体氮、磷污染状况分析   总被引：25，自引：4，他引：21  

王毛兰  周文斌  胡春华 《湖泊科学》2008,20(3):334-338

通过系统测定鄱阳湖湖水、主要入湖口河水及部分农田水、地下水及城市污水氮磷含量,对其氮、磷污染状况进行了分析,同时对湖水及河水的氮、磷来源进行了初步讨论.结果表明,鄱阳湖区水体已达到一定程度的氮、磷污染,特别是饶河段氮含量较高(0.89-3.15mg/L),信江磷含量较高(0.098-0.22mg/L),而湖体的总氮、总磷含量也分别达到1.06±0.28mg/L和0.067±0.042mg/L,已具备富营养化的条件.  相似文献   

The Light Regime Effect on Triacylglycerol Accumulation of Isochrysis zhangjiangensis     

FAN Xuran  CAO Xupeng  CHU Yadong  WU Peichun  XUE Song 《中国海洋大学学报(英文版)》2019,(2):474-480

Stress state of microalgal cells is caused under unfavorable conditions such as disordered light regime and depleted nitrogen. The stress state can impair photosynthetic efficiency, inhibit cell growth and result in the accumulation of triacylglycerol(TAG) from protective mechanisms. Continuous light or nitrogen starvation was applied on microalgae and performed effectively on inducing TAG production. To evaluate the light regime effect on inducing TAG production, the effect of different light regimes on nitrogen-starved Isochrysis zhangjiangensis was investigated in this work. The continuous light and nitrogen starvation elevated TAG content of biomass by 73% and 193%, respectively. Furthermore, the TAG accumulation of I. zhangjiangensis cell under nitrogen starvation decreased under aggravated stress from continuous illumination. Our results demonstrated that culturing the cells with 14 L: 10 D light regime under nitrogen starvation is the optimal mode to achieve maximal accumulation of TAG. A recovery in light regime was necessary for I. zhangjiangensis cultivation.  相似文献   

Identification of hyperspectral vegetation indices for Mediterranean pasture characterization     

F. Fava  R. Colombo  S. Bocchi  M. Meroni  M. Sitzia  N. Fois  C. Zucca 《International Journal of Applied Earth Observation and Geoinformation》2009

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Carbon and nitrogen isotope composition of particulate organic matter in relation to mucilage formation in the northern Adriatic Sea   总被引：1，自引：0，他引：1  

J. Faganeli  N. Ogrinc  N. Kovac  K. Kukovec  I. Falnoga  P. Mozetic  O. Bajt 《Marine Chemistry》2009,114(3-4):102-109

Carbon and nitrogen stable isotope ratios of particulate organic matter (POM) were studied approximately weekly during spring and summer 2003 and 2004 in the Gulf of Trieste (northern Adriatic Sea) in order to track the temporal variations and differences between two years. In parallel, particulate organic carbon (POC) and particulate nitrogen (PN), phytoplankton biomass (chlorophyll a), and N and P nutrients were monitored. All studied parameters, especially N and P nutrients and chlorophyll a, showed higher concentrations and larger variability in spring 2004. As a consequence the macroaggregates were produced in late spring 2004. The C and N isotope composition of POM was not directly linked to phytoplankton biomass dynamics. The δ¹³C_POC values covaried with temperature. In 2004, δ¹³C_POC variations followed the δ¹⁵N_PN values as well as the δ¹³C_DIC values which were probably more dependent on the photosynthetic use of ¹²C. Variations in δ¹⁵N_POM values were most probably the consequence of variations in N nutrient sources used in phytoplankton assimilation. The significant correlation between δ¹⁵N_PN values and nitrate concentrations in 2004 implies intense nitrate assimilation in the presence of higher nitrate concentration. This suggests nitrate as the key nutrient in the »new primary production«, later producing macroaggregates with a mean δ¹³C and δ¹⁵N values of − 19‰ and 5‰, respectively. A low fractionation factor ε, < 1‰, lower than that reported in other marine and lacustrine systems, was found probably to be a consequence of distinct phytoplankton species, i.e. several classes of autotrophic nanoflagellates, and specific growth conditions present in the Gulf of Trieste. The tentative use of C isotope composition of POM revealed a higher contribution of allochthonous organic matter in 2004 compared to 2003 due to higher riverine inflow.  相似文献   

沙海蜇(Nemopilema nomurai)模拟消亡过程中氮与磷的释放     

李学刚  李宁  马清霞  袁华茂  段丽琴  宋金明 《海洋与湖沼》2012,43(3):507-512

在实验室内模拟研究了沙海蜇消亡过程中氮与磷的释放特征。模拟结果表明:沙海蜇消亡过程中向水体释放氮、磷可分为两个阶段,且氮的释放速率比磷高一个数量级。在沙海蜇消亡的初期阶段,水体中溶解态氮、磷和总氮、总磷的浓度迅速增高,氮可以达到其消亡过程中的最高浓度;在后期阶段,水体中溶解态氮和总氮的浓度不断下降,但水体中的磷在这一阶段达到消亡过程中的最高浓度碱性条件有利于氮的释放,酸性条件有利于磷的释放;盐度越高氮与磷的释放速率越小;温度对氮、磷的释放影响不大;水体中氮与磷含量越高,沙海蜇消亡的速度越慢,而且氮的浓度越高,氮与磷释放到水体中的速率就越慢。  相似文献   

湖泊沉积物氮磷内源负荷模拟   总被引：75，自引：1，他引：75  

范成新  张路  杨龙元  黄文钰  许朋柱 《海洋与湖沼》2002,33(4):370-378

在对骆马湖沉积物及其间隙水物化性质、空间分布等分析基础上 ,在实验室控制的恒温静态条件下 ,模拟了软性富泥区柱状芯样在不同季节温度下的沉积物 水界面氮、磷交换过程。根据模拟不同温度下的柱状沉积物氮、磷释放速率及其代表时段下的物质释放量计算 ,以及应用孔隙水物质扩散模型进行的计算 ,全湖内源氮、磷负荷分别约为 ( 1 1 1 3.2± 71 .3)t/a和 ( 1 2 .5 0± 0 .95 )t/a,分别占骆马湖年氮、磷入湖量的 7.4%和 1 .2 %。沉积物中氮、磷含量差异大及铁含量较高可能是氮释放通量偏高和磷释放通量较小的主要因素。  相似文献   

地下水NO3^-氮与氧同位素研究进展     

邓林曹玉清  王文科 《地球科学进展》2007,22(7):716-724

人为活动通常是地下水硝酸盐污染的主要原因。不同来源的NO3^-具有不同的氮、氧同位素组成,利用地下水NO3^-中的δ15N和δ18O值可有效识别地下水硝酸盐污染的来源。引起地下水中NO3^-含量显著减少的不同物理、化学和生物过程,所产生的氮、氧同位素分馏效应有明显差别。地下水系统中反硝化作用发生时,NO3^-中氮和氧同位素分馏系数呈一定比例。因此NO3^-中δ15N和δ18O值也是示踪地下水硝酸盐循环,尤其是反硝化作用的有效手段。利用NO3^-中氮和氧双同位素,并与其他环境同位素及化学分析技术相结合,示踪NO3^-来源及其循环是地下水硝酸盐污染研究的重要方向之一。综述了利用地下水硝酸盐中氮和氧同位素识别NO3^-污染源与循环的研究进展,简述了近年迅速发展的阴离子交换树脂取样法,概述了此方面研究存在的主要问题,并展望了今后的研究方向。  相似文献