闽江河口淡水、半咸水沼泽土壤碳氮磷分布及计量学特征

以闽江河口区淡水、半咸水短叶茳芏沼泽湿地为研究对象,于2013年11月~2014年8月分季节采集表层土壤样品,研究土壤有机碳(SOC)、总氮(TN)、总磷(TP)含量时空变异格局及其计量学特征,并同步观测相关环境因子.结果表明,淡水、半咸水沼泽土壤SOC、TN、TP含量范围分别为(18.24~28.36,1.44~2.24,0.45~1.01)(14.96~26.19,1.55~2.45,0.67~1.18)g/kg.淡水沼泽土壤各元素含量均具有明显的垂直变化规律;而半咸水沼泽除TN含量垂直变异明显外,其他各指标则表现为波动变化的特征.淡水、半咸水沼泽土壤C/N、C/P、N/P均值分别为12.41±1.22,29.77±6.76,2.40±0.47以及10.89±1.09,24.92±3.80,2.29±0.25.方差分析显示,各指标含量在两个沼泽均存在显著空间差异.两个沼泽土壤SOC、TP、C/N、C/P均与土壤pH和EC呈显著相关关系,而与含水率和容重相关性不显著;土壤C/N均与粉砂粒和砂粒呈极显著相关关系;土壤SOC、TN、TP含量对C/N、C/P、N/P影响显著.淡水、半咸水沼泽土壤营养元素含量分布特征是水动力学作用、外源物质输入、植物生产力和人类活动等多因子综合作用的结果.     

洪湖沉积柱中重金属的历史分布特征及来源

为了解历史上洪湖重金属的含量水平及来源,于2014年12月在洪湖中心位置采集了沉积柱,分析了沉积柱中4种重金属（Cu、Cd、Zn、Pb）的含量,并结合¹³⁷Cs和²¹⁰Pb定年技术得到沉积物中重金属高分辨率年代沉积序列.结果表明：洪湖沉积柱中4种重金属总量介于67.86~189.57mg/kg之间,4种重金属含量的高低为Pb>Zn>Cu>Cd.地累计指数表明Cu和Zn未达到污染级别,而Pb为无污染到中度污染级别,Cd为中度污染到强污染级别.沉积物中重金属含量受洪水和围湖造田的共同影响,新滩水闸建成前,洪水会导致沉积物中重金属含量先降低,随后升高.水闸建成后,洪水会导致洪湖出现内涝致使沉积物中重金属含量升高;围湖造田导致沉积物中重金属含量升高.源解析研究表明,沉积物重金属来源于非点源农业污染、交通活动以及工业废水和生活废水排放.     

中国近海和河口环境铜污染的状况

我国铜消费量已稳居世界前列,但随之而来的是铜带来的环境污染压力。铜污染问题不但在内陆环境逐渐突出,而且在近海和河口环境也日趋严重。通过分析近年来发表的我国近海河口海水、沉积物、牡蛎的铜含量数据,评估我国近海和河口环境的铜污染现状。数据显示,我国近海和河口环境大部分地区铜污染水平较低,但存在个别污染严重的区域。沉积物柱状样的数据显示,我国近海河口环境铜污染水平在过去几十年中呈逐渐上升趋势。铜污染已经开始威胁我国近海和河口环境的健康发展。"蓝牡蛎"和"绿牡蛎"是我国近海河口生物受铜污染影响的一个典型例子。多地发现"蓝牡蛎"的现象印证了铜污染源在近海河口环境普遍存在的观点。牡蛎受重金属污染而变色是一个值得研究的污染现象,它包含了复杂的生物学和生态学因素。本文探讨了"蓝牡蛎"和"绿牡蛎"形成的机制。     

Extraction of anthropogenic heavy metals from reduced sediments: Indeterminations due to authigenic sulphides and clay minerals

A mineralogical and micro‐chemical study was performed by X‐ray diffraction and SEM/EDS techniques in a reduced sediment sample from the Venice Lagoon to investigate selectivity and significance of two widely used acid extractions (cold IN HCl and hot 8N HNO₃) for the evaluation of anthropogenic metal concentrations. Hydrochloric acid determines an incomplete and variable solubilization of authigenic iron sulphides, yielding a partial extraction of the associated metals (Hg, Mn, Zn and less Ni and Cu). Nitric acid is effective in solubilizing all sulphides, however, it leads to an overestimate of the anthropogenic metal content since it partially dissolves the lattice of some clay‐minerals, particularly chlorites. When these acid extractions are used to asses metal pollution in aquatic ecosystems, the possible over or under‐estimate of the anthropogenic concentration must be taken into account, considering the mineralogical composition of the sediment.     

Seasonal and spatial variations of acid-volatile sulphide and simultaneously extracted metals in the Yangtze River Estuary

Surface sediments were collected from the Yangtze River Estuary (YRE) in May 2012, August 2012, November 2012 and February 2013 to analyse the seasonal and spatial distributions of acid-volatile sulphide (AVS), simultaneously extracted metals (SEM) and the sediment toxicity. An optimised method was used for the AVS and SEM analysis and the results showed that the seasonal variations of AVS were positively correlated with changes in water temperature and the position of higher AVS was relatively fixed. The average of SEM was gradually increased from May 2012 to February 2013 and there were abnormally high values of SEM_Cu and SEM_Ni in the YRE. Concentrations of the five SEM components were in the following order: Cd?相似文献   

Heavy metal concentration in water,sediment, and tissues of fish species (Heteropneustis fossilis and Puntius ticto) from Kali River,India

The river Kali has been one of the major recipients of industrial effluents in the Muzaffarnagar district of western Uttar Pradesh. The present studies revealed the occurrence and bioaccumulation of heavy metals (Cd, Cr, Pb, Zn, Mn) in riverine water, sediment, and muscles of two fish species, Heteropneustis fossilis and Puntius ticto. Data showed that the order of occurrence of heavy metals was Pb > Zn > Mn > Cr > Cd in river water, Mn > Zn > Pb > Cr > Cd in sediment, Zn > Mn > Cr > Cd > Pb in Puntius ticto and Cr > Zn > Mn > Cd > Pb in Heteropneustis fossilis. Results indicate that the concentrations of Cd, Pb, and Zn in river water, Pb, Zn, and Mn in sediment, Cd, Cr, Pb, and Zn concentration in muscles of Puntius ticto and Cr, Pb, and Zn concentration in in muscles of Heteropneustis fossilis are higher than the permissible standard limits. The presence of heavy metals contributed to toxicity in different organs of fish in River Kali. The bioaccumulation of heavy metals in different biotic organisms in river ecosystem may have adverse consequences on humans and livestock.     

Sources and Distribution of Heavy Metals in East China Sea Surface Sediments

Box cores and surficial sediments collected from the shelf, slope and Okinawa Trough of the East China Sea were analyzed for loss on ignition, and concentration and speciation of Al, Fe, Mn, Pb, Cd, Cu and Zn. in general, concentrations of these metals are higher in the inner shelf and lower in the midshelf, but the highest LOI, Cd and Mn levels are found in the Okinawa Trough. Spatial distributions of these metals in surficial sediments indicate that the Yangtze River is the major source for materials deposited in the inner shelf. the results of a six-stage sequential leaching experiment indicate that the fluvial input includes natural (e.g., Al and Fe) and anthropogenic (e.g., Pb) materials. the depletion concentration of these metals in the midshelf sediments reflects the dominance (～ 70%) of coarse, relict sand, while the enrichments in the inner shelf and the Okinawa Trough sediments are due to the fine grained, organic-rich sediments. the speciation of Mn in the sediments of the Okinawa Trough indicates that its distribution is diagentically or hydrothermally controlled.     

Metal distribution in marine sediments of the Mar Piccolo in Taranto (Ionic Sea,southern Italy)

The spatial distribution of selected metals (Fe, Ni, Mn, Zn, Cu, Pb, Hg and Cd) and their partition in the different chemical forms (speciation) were determined in benthic sediments from Mar Piccolo, Taranto (Ionic Sea, southern Italy). The aim of this study was to assess the degree of sediment contamination and bioavailability of metals, very important for Italian mussel culture, in a semi-enclosed marine ecosystem. In sediments, grain size distribution, total organic carbon (TOC), and humic (HA) and fulvic (FA) acids contents were also determined. The compounds TOC, HA and FA, in fact, have a great influence on metal complexation. High concentrations of copper, lead, zinc and mercury were found, especially in sediments of the first inlet of Mar Piccolo. Statistical analysis of results shows significant correlation among Cu, Pb and Zn concentrations and the influence of organic matter on the sediment distribution of Cu, Pb and Zn. Metal speciation analysis, carried out with sequential extraction method, shows that Fe and Ni are present in sediments mainly as sulphides. Mn and Pb are present principally in an ion-exchangeable form or bound to carbonate and Cu is associated to organic matter. Metal pollution index (MPI), calculated as a weighed mean of the metal contamination factors in each station, shows that with regard to Cu, Ni, Pb and Zn, some stations investigated are unpolluted (MPI <1), whereas in other areas, pollution level is not very high. On the contrary, for mercury, the pollution level in the first inlet of the basin is very high.     

Methodological approach for metal pollution evaluation in sediments collected from the Taranto Gulf

The concentrations of Hg, Cd, Pb, Cu, Ni, V, and Sn were determined in marine sediments collected from Taranto Gulf (Ionian Sea, Southern Italy). The aim of this article is to study the methodological approach in order to evaluate total metal levels determined in marine sediments of a contaminated area (Taranto Gulf, Southern Italy), to identify contaminated areas and to predict adverse biological effects based on Sediment Quality Guidelines (SQGs). The results are discussed in relation to geological characteristics of sediments in order to define background levels and anthropogenic input. Experimental results were elaborated by multivariate statistical techniques and Geographical Information System (GIS) software. The geoaccumulation index I _geo and two sets of SQGs (in particular (a) the threshold effect level (TEL), the probable effect level (PEL) and (b) the effect range-low (ERL) and the effect range median (ERM)) have been used for environmental evaluation of metal concentrations. Results show that in Taranto coastal area, Mar Piccolo basin represents the most contaminated area. A comparison with results from other Mediterranean areas demonstrates that for some metals (such as Cd, Pb, and Hg) Taranto seas represent one of the most polluted areas in the Mediterranean Sea. A comparison of metal levels with SQGs also suggests an ecotoxicological risk for benthic organisms mainly in the first inlet of Mar Piccolo.