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151.
Konstantinos Komnitsas Ioannis Pyliotis Dimitra Zaharaki Emmanouil Manoutsoglou 《Environmental Forensics》2015,16(1):109-116
The aim of the present study is to explore the implications of using different quality guidelines and approaches for marine sediment characterization. As a case study, the sediments of Souda Port, Crete, Greece, were examined in order to assess heavy metal contamination and to estimate anthropogenic contribution and potential adverse effects to aquatic environment, as well as to indicate feasible future management options. The concentration of six heavy metals (Co, Cr, Cu, Ni, Pb, and Zn) was determined and compared with different sediment quality guidelines (SQGs) and regional/national criteria established for dredged material characterization and management. In addition, the geo-accumulation index (Igeo) was calculated and the sediments toxicity and heavy metals bioavailability were determined. Based on the experimental data, it is deduced that Souda sediments are characterized as moderately polluted only in terms of Co, Ni, and Pb. 相似文献
152.
The utilization of reclaimed water could be an efficient tool to alleviate water scarcity,especially for dry river augmentation.However,it is crucial to monitor water quality to ensure safety to human health and to avoid negative effects on the environment.Reclaimed water samples were collected bimonthly from May to November in 2010 in Chaobai River,and the physiochemical parameters were determined.The main results are as follows:The parameters exceeding the threshold value of the water guidelines are mainly nutrition related to nitrogen and phosphorus,which are known to increase the risk of eutrophication in surface waters.Additionally,nitrite and nitrate can be detrimental to human health.The majority of the parameters have a peaking concentration in May,whereas others either show significant temporal variation over the entire period or remain relatively constant in all four months.Correlation analysis shows that some parameters(pH,T and B) have no significant correlation with others,whereas significant positive correlation was found for Sr with EC and TDS,for CI with TDS,for Si02 with TP and for NO3-N with TN and a significant negative correlation between SO4 and Ba.According to principal component analysis,60.108%of the total data is represented by dominant solutes,and the second principal component with a percentage of 31.876 comprises parameters related to nitrogen.Subsequent cluster analysis of parameters identified four groups,which represent different compositions,and samples in May differ from others. 相似文献
153.
Stream-bed sediment samples were collected in 2001 and 2004 along the Fratta-Gorzone River (Italy) to assess the level of
heavy metal contamination. The river stretch most affected by discharges of tannery effluent showed total and pseudo-total
Cr levels (up to 2,860 mg/kg) that greatly exceed national and international chemical sediment quality standards. The most
contaminated section of the river bed is located downstream of the main industrial discharge. However, a large fraction of
the Cr present in the sediment appears to be of lithogenic origin. At most sites, more than 50% of Cr is not soluble in aqua-regia
and thus unlikely to be very mobile or easily bio-available. A negligible risk to the benthic community can be inferred for
Pb, Zn, Cd, Cu and Ni. This work highlights the limitation of using existing chemical sediment quality standards alone for
risk assessment. The collection and analysis of suspended solids, the determination of river discharge and of dissolved Cr
at 10 field stations allowed to estimate the particulate and dissolved Cr load and to locate the river stretch that was the
likely source of contaminated sediment. The pumping of dilution water from the Adige River into the Fratta-Gorzone River did
not produce the expected contaminant dilution effect due to re-suspension of contaminated solid particles and the release
of Cr in solution. 相似文献
154.
This study examines the impact of the creation of marine protected areas (MPAs), from both economic and biological perspectives. In particular, we examine the effects of protected patches and harvesting on resource populations. We conclude that protected patches are an effective means of conserving resource populations, even though extinction cannot be prevented in all cases. We discuss the dynamic optimization of a harvest policy by choosing E(t), the harvesting effort, as the dynamic variable. We also discuss the optimal equilibrium harvest policy and explain the biological and bioeconomic interpretations of the results. 相似文献
155.
156.
16S rRNA高通量测序研究集雨窖水中微生物群落结构及多样性 总被引:5,自引:15,他引:5
为探究集雨窖水中细菌多样性及功能与主要水质因子之间关系,应用16S rRNA基因-Illumina MiSeq高通量测序技术分析和比较了不同类型集雨水窖中窖水的微生物群落结构及多样性.通过提取4组样品基因组DNA,对16S rRNA V4区测序,共获得用于物种分类的OTU 1605条,涵盖了22门、42纲、71目、115科、146属的细菌.微生物多样性分析表明,窖水具有很高的细菌多样性,不同样品多样性存在差异,细菌优势菌群分布呈现出大量的稀有种和少数常见种的模式.菌群分类发现,拟杆菌门(Bacteroidetes)、变形菌门(Proteobacteria)、放线细菌门(Actinobacteria)、疣微菌门(Verrucomicrobia)和OD1是主要的细菌菌门,其相对丰度占群落的87.1%~94.8%;放线菌门的放线细菌纲(Actinobacteria)、酸微菌纲(Acidimicrobiia),拟杆菌门的噬纤维菌纲(Cytophagia)、黄杆菌纲(Flavobacteriia)、鞘脂杆菌纲(Sphingobacteriia),变形菌门中α-变形菌纲(α-Proteobacteria)、β-变形菌纲(β-Proteobacteria)、γ-变形菌纲(γ-Proteobacteria),疣微菌门丰收神菌纲(Opitutae)、疣微菌纲(Verrucomicrobiae)、Pedosphaerae,OD1的ZB2为纲层次上的优势菌;红细菌属(Rhodobacter)、脱氮单孢菌属(Dechloromonas)、黄杆菌属(Flavobacterium)、不动杆菌属(Acinetobacter)、丛毛单孢菌属(Comamonas)、假单孢菌属(Pseudomonas)、嗜氢菌属(Hydrogenophaga)等优势菌属大多数为具有脱氮除磷功能的反硝化菌和异养硝化-好氧反硝化菌;RDA分析表明,不同环境因子对微生物群落的影响有着明显的不同,即第Ⅱ簇内的菌属主要与反映窖水有机物含量的指标UV254、高锰酸盐指数、BOD5之间呈显著正相关关系,而第Ⅲ簇内的菌属主要与反映窖水氮、磷水平的指标TN、NO2--N、NO3--N、TP、NH4+-N显著正相关,体现了生态功能的簇内相似性及簇间差异性.研究结果加深了对窖水微生物群落结构和多样性的认识,为深入研究窖水细菌多样性及功能与水质因子之间关系提供了借鉴. 相似文献
157.
美国水质基准技术分析与我国相关基准的构建 总被引:14,自引:10,他引:14
介绍了以保护自然生态系统中水生生物为主要目标的美国水质基准技术指南. “指南"在研究个体水平的动、植物毒性数据的基础上进行数理分析,得出数值化的环境水质基准,并给出了相关计算模式和技术路线. 指出基准构建在种群、群落和生态系统水平等的毒性试验数据应用方面还有待发展完善,另外,“指南”中选择的试验生物也不适用于我国水质基准的制订研究. 以辽河流域为例,对我国水质基准的研究提出如下建议:①试验生物应选择有区域代表性的特征物种,我国基本可以采用US EPA规定的物种选用原则,但须包括鲤科鱼类;②关注种群和群落水平的毒性数据;③基于当地物种和水质状况或水生态功能分区信息制订区域水质基准. 相似文献
158.
黄河口表层沉积物中重金属的环境地球化学特征 总被引:15,自引:6,他引:15
为了探讨多重环境因素变化下黄河口沉积物中重金属的环境地球化学行为,研究了2011年7~8月黄河口14个表层沉积物样品中Cu、Pb、Zn、Cr、As和Hg等6种重金属的分布特征、环境影响因素及其生态风险.结果表明,黄河口表层沉积物中6种重金属平均含量分别为Cu:(16.5±2.7)mg.kg-1,Pb:(16.0±3.4)mg.kg-1,Zn:(21.0±3.3)mg.kg-1,Cr:(17.4±3.1)mg.kg-1,As:(6.5±1.2)mg.kg-1,Hg:(0.044 4±0.030 7)mg.kg-1.与我国近海其它区域比较,研究区域重金属含量均处于较低水平.表层沉积物中河口南侧沉积物中重金属含量比北侧高,并随河口向外沉积物中重金属含量逐渐降低,此分布趋势在莱州湾西南部尤为明显.重金属间无显著相关关系,重金属含量与细颗粒物、总有机碳(total organic carbon,TOC)之间亦无显著相关关系,表明黄河口表层沉积物中重金属受到汛期黄河上游复杂来源的影响,且粒度、TOC皆非主控因素;TOC与黏土的相关系数达0.724(P<0.05),显示TOC更易富集于黏土中.与多种背景值及一致性沉积物质量基准比较,黄河口部分站位Pb含量超出背景值,但该含量水平引发有害生物效应的可能性不大,尽管重金属含量偏低,生态风险较小,但近年来Hg、Pb的风险有升高的趋势. 相似文献
159.
通过对2013年10月东北三江平原农作物收获期大气颗粒物的在线监测,结合卫星火点数据与后向轨迹模拟,分析了秸秆燃烧和作物收割等农业活动对大气颗粒物质量浓度及粒径分布的影响.结果表明:作物收获前期?中期和后期大气PM2.5的平均质量浓度分别为36.0,158.3,33.8μg/m3;现场观测表明,水稻收割(321.1μg/m3)和秸秆燃烧(2777.1μg/m3)时监测田块内PM2.5的平均浓度分别是收割前和燃烧前平均浓度的2.5倍和11.5倍;卫星火点及后向轨迹分析发现,观测期间PM2.5与该地区卫星火点数量的变化趋势比较一致,且气团轨迹经过火点较集中区域时测得较高的PM2.5浓度值;对不同粒径(<1μm,1~2.5μm,2.5~10μm)大气颗粒物质量浓度的观测表明,收获中期受大面积秸秆燃烧的影响,0~1 μm粒径组分明显增加,而收获后期由于降水过程对0~1μm粒径颗粒物的清除效率较低,故该粒径颗粒物仍维持较高比例. 相似文献
160.
采用底泥质量标准(SQGs)法和潜在生态风险(RI)法对滇池外海22个点位20cm柱状底泥中重金属As、Hg、Cr、Cd、Pb、Zn和Cu浓度分布及潜在生态风险进行了研究.结果表明,Pb的最高浓度达319mg/kg,9个点位超过风险评价中值或高概率效应浓度,是超标最严重的重金属.各元素污染程度顺序为PbCuHgAsCdCrZn.Pb、Cu、Hg的污染层为15~20cm,其余重金属污染层为10~15cm.潜在生态风险(RI)评价表明,滇池外海底泥重金属污染总体处于中等生态风险水平,北部为"强"等级,潜在风险顺序为HgCdAsPbCuCrZn.两种方法的评价结果具有一定的差异性,在实际应用中需结合起来使用.此外,滇池底泥重金属浓度与潜在生态风险表现出一致的区域性差异,即北部大于南部,西部大于东部. 相似文献