Water flow and solute transport model of potentially toxic elements through unsaturated zone at regional wellfield Kosnica          下载免费PDF全文

Stanko Ružičić  Marta Mileusnić  Kristijan Posavec  Zoran Nakić  Goran Durn  Vilim Filipović 《水文研究》2016,30(22):4113-4124

The objective of this work was to build a prognostic water flow model and potentially toxic elements (lead, cadmium, zinc) transport model in the unsaturated zone. Research was conducted in the catchment area of Kosnica regional wellfield, where the unsaturated zone is characterised by Fluvisol. Lower sorption capacities were determined in the first horizons for all three potentially toxic elements. Correlation coefficient of the measured and simulated values of tracer concentration is 0.58 for the AC horizon and 0.84 for the 2C/C1 horizon. Based on calibrated water flow and transport parameters, a prognostic water flow model and potentially toxic elements (lead, cadmium, zinc) transport model in the unsaturated zone was built. In case of an accidental spill of potentially toxic elements with concentrations of 1000 mg/l, the risk of contamination of the aquifer is present. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

一种户外开放式微藻培养体系优化     

周艳  汪旭  王蕴博  徐海青  王仕举  窦世娟  杨明  李莉云  刘国振 《广东海洋大学学报》2021,(2)

【目的】建立可用于大规模培养的户外开放式微藻培养体系。【方法】设计一种微藻平面开放浅层培养(Flat,open and shallow,FOS,简称浮法)体系,以小球藻(Chlorella sorokiniana)为模式藻种,探讨温度、光照、pH值和培养基营养成分等因素在该培养体系中对小球藻生长的影响,开展900 L体系的户外培养试验。【结果】浮法体系主要由塑料袋和垫板组成,在该培养体系中的小球藻在20~40℃范围内均可生长,最适生长温度为30~35℃。小球藻生长有明显的照度依赖性,无光时几不生长,随着照度升高,生长速度加快,在较高的照度下表现有光饱和现象。以TAP为基础培养基,在碳源或氮源缺乏时小球藻几不生长。pH 7.5左右有利于小球藻生长。900 L体系的户外培养试验的生物量(干物质得率)为0.15 g/(L·d)。【结论】在此新型户外平面开放浅层微藻培养体系中,温度、照度、pH值及营养成分等对小球藻的生长均有不同程度的影响。该体系有成本低、操作简便、容易控制、自然资源利用率高等特点,有大面积推广潜力。  相似文献   

Joint toxic effects of heavy metals and atrazine on invasive plant species <Emphasis Type="Italic">Solidago Canadensis L</Emphasis>.     

HAN Zhaoxiang*  HE Gu  ong  WANG Jiahong  Lü Chunxia School of Chemical Engineering  Huaihai Institute of Technology  Lianyungang  China School of the Environment  Nanjing University  Nanjing  China Jiaonan Agricultural Bureau  Qingdao  China 《中国地球化学学报》2011,30(4):523-530

In this study, the joint effects of Cd(Ⅱ), Pb(Ⅱ) and atrazine (ATR) on Solidago Canadensis L. were investigated. The results showed that soil containing Cd, Pb and ATR could inhibit root elongation of Solidago Canadensis L., and that there was a positive linear relationship between the inhibitory rate of root elongation and the concentrations of Pb(Ⅱ). The mixture of Cd(Ⅱ) and Pb(Ⅱ)-ATR in soil showed a significant adverse effect on root and shoot biomass of Solidago Canadensis L. Acetylsalicylic acid (ASA) contents increased slightly at the lower concentrations of Cd(Ⅱ)-ATR, then decreased when Cd(Ⅱ)-ATR concentrations were higher than those of 1.0 TUmix(Cd+ATR). The toxic effect of Pb(Ⅱ)-ATR on the ASA contents of Solidago Canadensis L. was greater than that of Cd(Ⅱ)-ATR. Soluble sugar contents firstly decreased and then increased with increasing concentrations of Cd(Ⅱ)-ATR and displayed fluctuation with increasing concentrations of Pb(Ⅱ)-ATR. Total protein contents in-creased with increasing concentrations of Cd(Ⅱ) and Pb(Ⅱ)-ATR , relative to the control sample. The NP-SH con-tents showed a significant increase up to 12.2 mg/gfw of Cd(Ⅱ)-ATR, followed by a significant decline to 4.5 mg/gfw after 14 days of exposure. The effect of Pb(Ⅱ)-ATR was similar to that of Cd(Ⅱ)-ATR but the amount of NP-SH was not higher than that of Cd(Ⅱ)-ATR.  相似文献   

Cloning and characterization of a delta-6 desaturase encoding gene from Nannochloropsis oculata     

马晓磊  俞建中  朱葆华  潘克厚  潘瑾  杨官品 《中国海洋湖沼学报》2011,29(2):290-296

A gene(NANOC-D6D) encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a cDNA library of Nannochloropsis oculata(Droop) D.J.Hibberd(Eustigmatophyceae).The unicellular marine microalga N.oculata synthesizes rich long chain polyunsaturated fatty acids(LCPUFAs),including eicosapentaenoic acid(20:5n-3,EPA).The deduced protein contains 474 amino acids that fold into 4 trans-membrane domains.The neighbor-joining phylogenetic tree indicates that NANOC-D6D is ...  相似文献   

四种单胞藻和海洋红酵母对刺参浮游幼虫生长与变态成活的影响     

张萍萍  李琪  孔令锋  于瑞海 《中国海洋大学学报(自然科学版)》2011,41(10):30-34

本实验研究4种单胞藻与海洋红酵母(Rhodomonas sp.)搭配以及单胞藻混合投喂对刺参浮游幼虫体长生长及变态存活率的影响。采用三角褐指藻(Phaeodactylum tricornutum)、小新月菱形藻(Nitzschia closteriumf.minutissima)、牟氏角毛藻(Chaetoceros muelleri)和等鞭金藻(Isochrysis galbana)与海洋红酵母分别以1∶0、0.8∶0.2、0.6∶0.4、0.4∶0.6、0.2∶0.8和0∶1的比例搭配投喂刺参浮游幼虫,观测浮游幼虫每天的体长变化以及变态成活率。结果表明,单胞藻与海洋红酵母以适当比例混合投喂能提高刺参幼虫的体长日增长率,单独投喂海洋红酵母的刺参变态成活率也显著高于单独投喂单胞藻组。采用2种单胞藻以0.5∶0.5的比例混合投喂浮游幼虫,结果表明牟氏角毛藻与小新月菱形藻混合投喂组刺参浮游幼虫的变态成活率高于牟氏角毛藻与等鞭金藻的混合组。  相似文献   

福建省山仔水库和杜塘水库沉积物叶绿素a比较研究     

林慧  苏玉萍  庄一廷  钟厚璋  林佳  金华 《福建地理》2011,(4):42-48

采集了福建省山仔水库和杜塘水库的冬季沉积物,采用显微镜观察和荧光分析方法,对不同深度沉积物叶绿素a的含量以及微藻的丰度进行了分析．研究结果表明,山仔水库沉积物表层叶绿素a含量达到4692ng／g底泥干重,微藻的丰度为33．79×10^6Cells／g底泥干重,其中蓝藻门的丰度为6．77×10^6Cells／g底泥干重;杜塘水库沉积物表层叶绿素a含量为2301ng／g底泥干重,微藻的丰度为16．5×10^6Cells／g底泥干重,其中蓝藻门丰度为8．91×10^6vvCells／g底泥干重,山仔水库沉积物表层叶绿素a的含量和微藻丰度都约是杜塘水库的2倍,沉积物中叶绿素a的含量和微藻的生物量与其富营养化程度表现出一致性：富营养化程度高的山仔水库,沉积物中叶绿素a含量和微藻丰度相应也高,沉积物叶绿素a含量可以反映2个水库水体的富营养化状态．  相似文献   

Standing crop and primary production of benthic microalgae on the tidal flats in Yueqing Bay     

Qiang Hao  Yuming Cai  Xiuren Ning  Chenggang Liu  Xin Peng  Xuexi Tang 《中国海洋大学学报(英文版)》2011,10(2):157-164

The standing stock and primary production of benthic microalgae on tidal flats were measured seasonally at 3 transects (Puqing, Dahengchuang and Puqi) in Yueqing Bay during 2002 2003. The results showed that the integral chlorophyll a (Chl a) concentration in tidal flat mud exhibited a seasonal variation with the order of magnitude: winter (14.0 4.2 mg m-2) > spring (13.0 6.3 mg m-2) > autumn (7.7 5.9 mg m-2) > summer (4.6 3.2 mg m-2). The primary production showed an order of magnitude: spring (270.5 224.9 mgC m-2 d-1)>winter (238.7 225.5 mgC m-2 d-1)>autumn (214.1 56.2 mgC m-2 d-1)>summer (71.6 44.6 mgC m-2 d-1). Both chlorophyll a and primary production showed maximum values in the surface layer of sediment, and decreased rapidly with increasing depth due to sun light limitation. The results of variance analysis indicated that seasonal variation and tidal flat condition affected Chl a greatly, but had no significant effect on primary production. The annual primary production of benthic microalgae on tidal flats in Yueqing Bay was estimated at 16143 tons carbon, which is sufficient to support 1.02×105 tons shellfish production. The environmental factors affecting chlorophyll and primary production on the tidal flats in Yueqing Bay were discussed. By comparing with other bays on China’s coast, it was observed that Yueqing Bay is a region with high benthic microalgae standing crop and primary production, which may be related to the type of its sediment.  相似文献   

Total concentration,speciation and mobility of potentially toxic elements in soils around a mining area in central Iran     

《Chemie der Erde / Geochemistry》2015,75(3):323-334

The current study was designed to investigate the extent and severity of contamination as well as the fractionation of potentially toxic elements (As, Cd, Cr, Cu, Pb, Zn, Ni) in minesoils and agricultural soils around a Pb–Zn mine in central Iran. For this purpose, 20 agricultural soils and eight minesoils were geochemically characterized. Results showed that minesoils contained elevated concentrations of As (12.9–254 mg kg⁻¹), Cd (1.2–55.1 mg kg⁻¹), Pb (137–6239 mg kg⁻¹) and Zn (516–48,889 mg kg⁻¹). The agricultural soils were also polluted by As (5.5–57.1 mg kg⁻¹), Cd (0.2–8.5 mg kg⁻¹), Pb (22–3451 mg kg⁻¹) and Zn (94–9907 mg kg⁻¹). The highest recorded concentrations for these elements were in soils influenced directly by tailing ponds. Chromium, Cu and Ni content in agricultural soils (with average value of 74.1, 34.6 and 50.7 mg kg⁻¹, respectively) were slightly higher than the minesoils (with average value of 54.5, 33.1 and 43.4 mg kg⁻¹, respectively). Sequential extraction data indicated that there were some differences between the speciation of PTEs in soil samples. In the agricultural soils, Zn and Cd were mainly associated with carbonate bound fraction, As and Pb with reducible fraction, Cu with oxidisable fraction and Cr and Ni with residual phase. With respect to mobility factor values, Zn and Cd in the agricultural soils have been found to be the most mobile while As mobility is negligible. Also, the mobility factor of As, Cd and Pb in agricultural soils adjoining tailing ponds was high. In minesoil sample Cd was most abundant in the carbonate form, whereas other studied elements were mainly present in the reducible and residual fractions; therefore, despite the high total concentrations of As, Pb and Zn in the minesoils, the environmental risk of these elements was low. Based on the obtained data, a portion of Cu, Cr and Ni input was from agricultural activities.  相似文献   

Ocean manganese nodules as stromatolite with a fractal like-signature     

《Physics and Chemistry of the Earth》2013

Deep-sea manganese (Mn) nodules are problematic in terms of factors such as their characteristic form and genesis. There are many reports of bacterial species from manganese nodules. However, the genesis of these nodules has not been fully confirmed. Samples, mainly from the Clarion Clipperton Fracture zone in the Pacific Ocean, were examined by mineralogical methods and X-ray CT. Thin sections of these samples showed columnar stromatolite structures with rhythmic bands. Mineralized bacteria were observed by SEM and TEM. Surface morphology could be described as having a fractal-like nature. The fractal characteristics of spherical to dome-like forms were fundamentally composed of at least four ranks. The 4th order form corresponds to the stromatolite dome top shapes. Similar granular domain units and porous characteristics in manganese nodules were clearly observed by X-ray CT sections. Mathematical simulation based on fractal models reproduced similar morphological characteristics to the natural samples. So, we arrived at the concluding hypothesis that manganese nodules are aggregated stromatolite with fractal-like characteristics. Furthermore, we discussed the possibility that the nature of the layer manganese oxide minerals as the major component of the nodule and associated Fe-oxyhydroxide minerals may become an absorber/scavenger of strategic heavy metals and also toxic metals in the environments.  相似文献   

微藻基因工程在高价值化合物生产上的应用     

王康  崔玉琳  高政权  孟春晓  秦松 《海洋科学》2021,45(12):142-149

微藻在生产蛋白质、油脂、色素等方面具有作为细胞工厂的潜力,在解决传统生物量生产和市场未来的一些局限性方面发挥着推进作用.基因工程促进了微藻的改良,推动了微藻的产业化进程.本文综述了近年来微藻基因工程的研究进展以及基因工程在微藻生产生物燃料、医药等方面的应用.本文能为基因工程技术在微藻中的研究及应用提供思路,从而使微藻以及微藻产品变得更具有经济竞争力.  相似文献