Phosphorus Fractionation in Core Sediments from Haihe River Mainstream,China

Sediments from Haihe River mainstream, located in Xingjiaquan, Zhangjiazui, Tianjin, were collected and examined on the basis of P fractionation. SMT (standards, measurements and testing) procedure was adopted to investigate the changes in P concentration with depth in the core sediments collected from the different sampling sites of Haihe River mainstream. The relationships among different P fractions, such as exchangeable P (Ex-P), metal oxide bounded P (NaOH-P), organic matter and grain size, were also discussed. The results indicate that in both sites the rank order of P fractions was HCl-P > Organic P (OP) > NaOH-P > Ex-P in terms of their concentration. The Ex-P represented < 4% of the sediment total P, while the NaOH-P ranged 5–21%. The calcium bound phosphorus (HCl-P) showed considerable contribution (53–80%) to the sediment total P loads. Silt/clay sized sediments exhibited significantly higher concentrations of HCl-P and Ex-P in both sites. However, coarse-sand-sized sediments exhibited significantly higher concentrations of OP in both sites and NaOH-P in Xingjiaquan. Multivariate statistics were performed to identify the factors that influenced the sediment P.     

Ecotoxicological Risk Assessment of Polychlorinated Biphenyls (PCBs) in Bank Sediments from along the Yamuna River in Delhi,India

The River Yamuna originates from the Yamunotri glacier of the Himalayas and travels 22 km in the Delhi region. The river is used for various purposes in Delhi including drinking water supply. Twenty-eight polychlorinated biphenyls (PCBs) congeners were measured in bank sediments along the river, and their ecotoxicological risk was evaluated. Concentrations of ∑28PCBs varied from 0.20–21.16 ng g^?1 (dry wt.) with mean and median values of 6.63 ng g^?1 and 5.84 ng g^?1 (±0.69 ng g^?1), respectively. The concentration of 12 dl-PCBs concentrations varied from 0.04–2.86 ng g^?1 with a mean of 1.04 ± 0.11 ng g^?1, and their toxic equivalency ranged between <0.01–28.67 pg WHO-TEQ g^?1 with a mean of 10.77 ± 1.06 pg WHO-TEQ g^?1. CB-37, CB-44, CB-114, and CB-118 congeners were dominant among all PCBs congeners. The tri-PCBs (49%) were the main contributors to the PCB homolog followed by tetra-PCBs (35%), and penta-PCB (14%). Because there are no environmental guidelines in India for PCBs in river and marine sediments, concentrations of PCBs and their toxic equivalents were compared in a screening-level assessment with established freshwater sediment quality guidelines and found lower than those guideline values, which suggests no adverse ecotoxicological effect.     

Oral Bioavailability of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans in Industrial Soils

In this study, the oral bioavailabilities of numerous 2,3,7,8-PCDD/F congeners were evaluated in soil samples from an industrial site. The purpose of this study is several-fold: (1) to compare the soil bioavailability results of the different PCDD/F congeners; (2) to evaluate the consistency of the bioavailability results with those obtained in an in vitro bioaccessibility study with simulated GI tract fluids; and (3) to develop quantitative bioavailability measurements that are appropriate for use in a health risk assessment for this site. Soil samples containing PCDD/F toxic equivalent (TEQ) concentrations ranging from 0.53–45.2 ng/g were administered to female Sprague Dawley rats via oral gavage. Reference formulations of PCDD/Fs were administered intravenously or by oral gavage. The overall relative bioavailability of PCDD/Fs in the soil samples on a TEQ basis ranged from 17 to 51%, with a mean of 38%. The results of the in vitro bioaccessibility study were consistent with the bioavailability results (mean extracted TEQ of 22%). Because of the clear relationship between increasing chlorination and decreasing bioavailability and bioaccessibility observed in this study, we suggest that simply extrapolating results from one congener to another may be associated with a high degree of uncertainty.     

Levels of Polychlorinated Dibenzo-P-Dioxins (PCDDs) and Polychlorinated Dibenzo-P-Furans (PCDFs) in the Atmosphere (PM10) of a Coastal Area of West Bengal,India

Particle-bound polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDDs/Fs) were analyzed in the coastal air of West Bengal, India. Total PCDD/Fs ranged from 4–2491 fg m^–3 with a mean of 355 fg m^–3 and their I-TEQ values ranged between 1 to 62.6 fg I-TEQ m^–3, with an average of 17.1 fg I-TEQ m^–3. The dominant congeners were OCDD (46%) OCDF (14%) 1,2,3,4,6,7,8-HpCDF (11%) and 1,2,3,4,6,7,8-HpCDD (10%) and accounted for >80% to the total PCDDs/Fs. TCDD (29%) > PeCDF (28%) > HxCDF (16%) > PeCDD (13%) were the dominant TEQ contributors. Rough estimates of tolerable daily intake (TDI) show a low health risk of exposure to PCDD/Fs measured in the ambient air of a rural coastal area of West Bengal, India.     

Concentrations of metals and PCDD/Fs and human health risks in the vicinity of a hazardous waste landfill: A follow-up study

In 2007, an environmental surveillance program to evaluate the impact of a hazardous waste landfill (HWL) located in Castellolí (Catalonia, Spain) was initiated. Between 2011 and 2014, samples of soil and air were collected inside the HWL as well as in nearby villages, and the concentrations of arsenic (As), some metals (cadmium (Cd), chromium (Cr), mercury (Hg), nickel (Ni), and lead (Pb)), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed. As expected, pollutant levels were higher inside the HWL than in the remaining points. In contrast, air concentrations were similar inside and outside the HWL. Furthermore, an increasing trend of the pollutant levels was not observed in any of the environmental monitors, either soil or air, when comparing with the results from the baseline (2007) and precedent surveys. The human exposure to those pollutants was estimated to contribute to 1–26% of the total exposure, after including the dietary intake. In any case, conclusions are partially limited by the scope of the investigation, which was conducted with a relatively low number of samples. Despite this limitation, it must be highlighted that health risks for the population living in the neighborhood of HWL were considered acceptable, according to international standards.     

海河流域森林生态系统服务功能评估

森林生态系统在流域中发挥着极其重要的生态作用,为流域发展提供着巨大的服务功能。本研究根据生态系统服务功能的内涵,建立了流域森林生态系统服务功能评价指标体系,利用市场价值法、影子工程法和生产成本法等,定量评价了海河流域森林生态系统服务功能的经济价值。结果表明：海河流域森林生态系统总价值2349.4亿元,其中直接价值358.7亿元,间接价值1990.7亿元。从不同的服务功能类型来看,其价值量大小依次为：涵养水源>固碳释氧>环境净化>提供产品>土壤保持>营养元素循环;从不同的森林类型来看,其价值量大小依次为：松柏类>灌丛>栎类>桦木类>混交林>杨树类>松杉类。但是从各种森林类型单位面积价值量来看,大小依次是：松杉类>松柏类>桦木类>混交林>栎类>杨树类>灌丛。从研究结果来看,海河流域森林生态系统服务功能价值巨大,该结果有利于加强人们对森林生态系统的认识,可以为流域生态系统管理、生态保护和生态补偿提供依据。     

Long-Term Environmental Surveillance and Health Risks of Metals and PCDD/Fs Around a Cement Plant in Catalonia,Spain

In this study, environmental data concerning the potential impact of a cement plant were updated, 10 years after a previous monitoring study. In 2011 and 2012, samples of soil, vegetation, and air were collected in the vicinity of a cement plant located in Santa Margarida i els Monjos (Barcelona, Catalonia, Spain). The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and those of a number of metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl, V, and Zn) were determined. The results were compared with data from two previous sampling campaigns, performed in 2000 and 2001. Vanadium was the only element presenting a significant increase in the three monitors. In turn, a significant decrease of PCDD/Fs was noted in vegetation, from 0.2 to 0.1 ng WHO-TEQ/kg. The Hazard Quotient (HQ) of exposure to all pollutants was below the safety limit, while cancer risk associated with the exposure to metals and PCDD/Fs was within the range considered as assumable (10^?6–10^?4). Despite the long period of time elapsed between campaigns (10 years) and the use of alternative fuels, the impact of the cement plant seems to be low, based on the emissions of the contaminants here evaluated.     

海河流域农田生态系统环境损益分析

根据生态系统服务的内涵,建立了海河流域农田生态系统服务功能评价指标体系,并利用市场价值法、影子工程法和机会成本法等,定量评价了海河流域农田生态系统服务的经济价值和农田环境成本.结果表明：2005年,海河流域农田生态系统环境效益总价值为1802.64亿元;其中,调节功能的价值（794.16亿元）占44.06%,支持功能的价值（1008.48亿元）占55.94%,提供产品和文化功能未进行核算.从不同的功能类型来看,其价值量大小依次为释氧>涵养水源>营养元素循环>土壤保持>废弃物净化>环境净化>固碳>秸秆还田.2005年,海河流域化肥流失和温室气体排放的环境成本较大,为422.93亿元.其中,化肥流失量为427.42×10⁴ t,成本为151.91亿元;产生的温室气体折算为CO₂的量为3599.65×10⁴ t,成本为271.02亿元.     

海河流域河流生境功能识别及区域差异

城市群快速发展严重影响着区域水生态系统的完整性,大尺度流域的河流生境功能辨识和分析尚缺乏系统研究。以海河流域为例,根据河段蜿蜒度、河段比降、断流风险、盐度等4个指标,构建了河流生境功能的分类指标体系。通过多源空间数据和人工判读,划分了6254条河段,在此基础上将河流生境类型划分为15类。通过52个监测样点的鱼类调查数据,分析了不同河流生境的水生生物特征差异,揭示了鱼类多样性高的区域多位于河流比降大、断流风险低的区域,而河流蜿蜒度对于鱼类多样性影响较小。根据京津冀13个地级市的河流生境差异,提出京津冀城市群的生态安全构建需要充分考虑河流生境的空间异质性,并制定融合城市发展目标、水资源利用需求和河流生境功能的综合指标体系。     

Stratified Communities of Methanogens in the Jiulong River Estuarine Sediments, Southern China

Methane is a potent greenhouse gas and produced mainly by methanogens. Few studies have specifically dealt so far with methanogens in estuarine environments. In this study, diversity and distribution of methanogens were investigated by clone library and T-RFLP analysis in a Jiulong River estuarine sediment core which contained clear sulfate–methane-transition zone. The majority of obtained sequences in clone libraries and T-RF peaks from T-RFLP analysis were assigned mainly to Methanosaeta, Methanomicrobiales and Methanosarcinales/ANME. The fragments of Methanosarcinales/ANME were most dominant group (mean 51 %) and composed largely of ANME-2a. In addition, Methanosaeta and Methanomicrobiales accounted for 21 and 28 % of all fragments. Therefore, the presence of Methanomicrobiales, Methanosaeta and ANME-2a was indicative of acetoclastic methanogenesis, hydrogenotrophic methanogenesis, and anaerobic methane oxidation in Jiulong River estuarine sediments. This study provided the important knowledge towards understanding methane cycling association of representative of methanogens involved in estuarine environments.     

基于陆地-水生态系统耦合的海河流域水生态功能分区

水生态功能分区是针对水生态系统特征的陆地生态系统划分,是为流域水生态管理提供生态背景和基本单元。陆地-水生态系统的耦合是水生态功能分区的核心,但多停留在个别小流域进行理论探讨,大型流域的实际案例较少。针对海河流域独特的气候、地貌、水文和人类活动特征,提出了水生态功能分区的三级指标体系。一级二级区针对气候、地貌、水文背景进行"自上而下"的分区,三级区针对人类活动对水资源、水环境、生境影响,采用"自下而上"的分区方法。最终,海河流域划分了6个一级区、16个二级区和73个三级区。研究充分体现了"以水定陆、以陆控水"的基本原则,以及"自下而上"和"自上而下"分区方法的优点,结果可为海河流域水生态管理提供科学依据,为水资源空间调配与合理利用、产业结构布局与区域协调等服务。     

Monitoring PCDD/Fs in Soil and Herbage Samples Collected Near a Hazardous Waste Incinerator: Health Risks for the Population Living Nearby

In 1998, we started a wide environmental surveillance program focused on evaluating the environmental impact of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) emitted by a new hazardous waste incinerator (HWI) (Tarragona County, Catalonia, Spain) and assessing the potential health risks for the population living nearby. The HWI began regular operations in 1999. Since then, periodical surveys have been performed. We report here the results concerning PCDD/F levels in 40 soil and 40 herbage samples collected in years 2004 and 2005, respectively, in the vicinity of the HWI. The human health risks derived from exposure to PCDD/Fs were also assessed. PCDD/F concentrations in soils ranged from 0.06 to 12.60 ng I-TEQ/kg, with median and mean values of 0.65 and 1.14 ng I-TEQ/kg, respectively. In herbage, PCDD/F concentrations ranged from 0.03 to 1.57 ng I-TEQ/kg, with median and mean values of 0.31 and 0.40 ng I-TEQ/kg, respectively. A comparison of these results with those from the baseline survey shows that, after six years of regular operation, the HWI did not significantly increase PCDD/F levels in soils and herbage in the surrounding environment. Moreover, PCDD/F emissions from the HWI do not mean additional significant risks for the health of the individuals living in the vicinity of the facility. The results of the current study together with those of recent investigations in municipal waste incinerators indicate that, when adequately controlled for PCDD/F emissions, modern waste incinerators should not portend any special concern for the populations living nearby.     

海河流域61种植物磷元素化学特征及地理分异

海河流域６１种植物磷元素化学特征及地理分异的分析结果表明：滨蒿（Ａｒｔｅｍｉｓｉａｓｃｏｐａｒｉａ）含磷量最高,达０．２１２％,浮萍（Ｌｅｍｎａｍｉｎｏｒ）最低,只有０．０４３％;玉米（Ｚｅａｍａｙｓ）、高粱（Ｓｏｒｇｈｕｍｖｕｌｇａｒｅ）、谷子（Ｐａｎｉｃｕｍｍｉｌｉａｃｅｕｍ）、水稻（Ｏｒｙｚａｓａｔｉｖａ）、小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ）、莜麦（Ａｖｅｎａｎｕｄａ）等谷物含磷量＜０．２００％,低于作物正常含量水平,反应了土壤缺磷特点。各类植物含磷量大小为：盐生植物＞天然草本植物＞农作物＞蔬菜＞落叶阔叶树＞灌木半灌木＞果树＞针叶树＞水生植物（Ｐ＜０．０５）。农作物各器官部位以果实含磷量最高达０．２３４％,其次是叶０．１６１％和茎０．１１１％,根最低,只有０．０８４％,这种结果造成土壤有效磷因收获而亏损。不同支流域植物磷的地理分布规律表现为：滹沱河流域＞永定河流域＞漳卫河流域＞潮白河流域＞大清河流域（Ｐ＜０．０５）。土壤中含磷量相对较低,以及盐碱土ｐＨ较高,不利于植物吸收磷,造成植物磷营养元素相对缺乏     

Temporal and Spatial Variation of Methylmercury in Sediments in the Second Songhua River,China

The methylmercury (MeHg) content in the Second Songhua River was investigated in this study. Compared with the former data, the following trends in temporal variation were observed. The MeHg content decreased in relation to the distance from the pollution source in 1977; it showed a decline in 1983 after the pollution source had been shut off for one year and continued to decline from 1983 to 1991 when the Second Songhua River was in a cleansing period. The MeHg content in most segments investigated in this study was higher than in 1991. Along the river, sediment samples were collected from the Baishan Segment to the Sifangtai Segment, and from the surface to the underlying layer to check the vertical trend. The MeHg content was high in the segments upstream due to the gold mines existing, with highest content in the Toudaogou Segment (10.0 ng/g). The MeHg content declined from the Jiapigou Segment (6.2 ng/g) to the Hongshi Segment (0.69 ng/g), and it gradually increased from the Hongshi Segment (0.69 ng/g) to the Hadawan Segment (1.8 ng/g). It was still lower than upstream. The MeHg content gradually decreased from the Hadawan Segment to the Zhaoyuan Segment. However, there was no clear trend from the Zhaoyuan Segment to the Sifangtai Segment, where the order of the MeHg content was the Sanzhan Segment > the Sifangtai Segment > the Zhaoyuan Segment > the Laozhou Segment. The vertical variation in sediments showed that the MeHg content in the surface layer was higher than in the underlying layer in all segments with the exception of the Hongshi Segment and the Zhaoyuan Segment. The pollution index of MeHg content in the Second Songhua River was also discussed.     

福建敖江口表层沉积硅藻空间分布特征

为探讨福建敖江口表层沉积硅藻空间分布特征,2019年7月对敖江口进行表层沉积硅藻的采样调查,并研究了硅藻与环境因子的关系。结果表明,从13个站点共检出硅藻114种,隶属于39属。硅藻丰度具有从河口向外海先减少后增加的变化特征。聚类分析表明,主要硅藻属种可划分为淡水种组合带和半咸水-咸水种组合带。典型对应分析（CCA）表明,表层海水温度和盐度是影响硅藻分布的主要环境变量。河口区盐度相对较低,主要分布淡水种双面曲壳藻、优美曲壳藻和颗粒沟链藻;外海区北部盐度相对较高,主要分布咸水种流水双菱藻;外海区南部盐度相对较低,主要分布淡水种优美曲壳藻和颗粒沟链藻;滩涂的沉积物较粗,主要分布优美曲壳藻。此外,河口区和外海区南部可能存在一定的水体污染。     

Heavy Metal Contamination in Sediments and Floodplain Topsoils of the Lean River Catchment,China

Heavy metals (Cd, Ni, Cu, Pb, and Zn) and total sulfur (TS) in both surficial sediments and adjacent floodplain topsoils of the Lean River catchment are investigated to comprehend the effects of flooding on heavy metals in soils, the evolution of the quality of sediments, and transfer of sediment metals. The results show that concentrations of metals except for Ni in soils are significantly correlated with those in sediments. At most upstream or downstream locations, sediment metal concentrations are found comparable to those in soils (sed/soil≈1). For Cu at locations close to the Dexing Copper Mine (DCM), flooding brought Cu-poor clays into the floodplain soil system and this leads to sed/soil<1, while at locations adjacent to the Yinshan Lead-zinc Mine (YLM), suspended solids containing high concentrations of iron and magnesium oxide absorb large quantities of dissolved Cd, Pb, and Zn and deposit on the floodplain during flooding (sed/soil>1). In spite of an elevated Cu production of the DCM, a significant decrease in sediment Cu concentrations is found as compared to those 10 years ago. The decrease may be due to the elevated Cu ore utilizing efficiency and the use of a new modern tailing pool. At the location closest to the Yinshan Lead-zinc Mine (YLM), Pb and Zn concentrations increased in recent sediments. In the Lean River, metal contamination in sediments cannot reach the location 60 km downstream of their sources in 2005.     

Perfluorinated Compounds Distribution and Source Identification in Sediments of Lake Victoria Gulf Basin

Perfluorooctanoic acid and perfluorooctane sulfonate were determined in the sediments from Winam Gulf, which is in the Kenyan side of Lake Victoria and in its source rivers. The sources of perfluorinated compounds within the Gulf of Lake Victoria have been identified and their levels determined for the first time, in this study, using SPE and HPLC-MS-MS analytical methodology. Variability in the concentrations of perfluorooctanoic acid and perfluorooctane sulfonate ranged from 1.4–99.1 and <1–57.5 ng/g in river sediments, respectively, which was higher than concentrations obtained from lake sediments (range perfluorooctanoic acid <1–24.1 ng/g and perfluorooctane sulfonate <1–4.0 ng/g). The results obtained suggested generalized point sources such as domestic and industrial waste indicated by significant correlation and regression of r² = 0.857. Sampling sites within and near sewage and water treatment facilities gave the highest concentrations of both analytes, and were observed to be the main source of perfluorinated compounds pollution. The lowest limit of quantification was 1 ng/g for both analytes and limits of detection were 0.1 and 0.2 ng/g for perfluorooctanoic acid and perfluorooctane sulfonate, respectively. Typical values for recovery obtained were higher than 78% from spiked amounts ranging from 1 to 150 ng. Quantifying perfluoro alkylated compounds in sediments have provided insights into their source, distribution, and mobility in the Lake Victoria Basin.     

Ecological Risks Assessment and Pollution Source Identification of Trace Elements in Contaminated Sediments from the Pearl River Delta, China

Sediments from 14 stations in the Foshan Waterway, a river crossing the industrial district of Guangdong Province, South China, were sampled and subsequently analyzed. The 14 stations were selected for the pollution discharging features of the river, such as the hydrology, the distribution of pollution sources, and the locations of wastewater outlets. The ecological risks were assessed, and the pollution sources were identified to provide valuable information for environmental impact assessment and pollution control. The spatial variability was high and the range were (in milligrams per kilogram dry weight): Pb, 46.0~382.8; Cu, 33.7~ 482.3; Zn, 62.2~1,568.7; Ni, 28.5~130.7; Cr, 34.7~1,656.1; Cd, 0.50~8.53; Hg, 0.02~8.27; and As, 5.77~66.09. The evaluation results of enrichment factor and potential ecological risk index indicate that the metal pollution in the surface and bottom sediments were severely polluted and could pose serious threat to the ecosystem in most stations. Although the hazard levels of the trace element differed among the stations, Hg was the most serious pollutant in all stations. The results of principal component analysis (PCA) show that the discharge of industrial wastewater is the most important polluting factor whereas domestic sewage, which contains a large amount of organic substances, accelerates metal deposition. And potential pollution sources were identified by the way of integrating the analysis results of PCA and data gained from the local government. Therefore, the conclusion is drawn that Foshan Waterway is seriously polluted with trace elements, both in the surface sediment (0 to 20 cm) and the bottom sediments (21 to 50 cm) are contaminated.     

Stratified Communities of Active Archaea in Shallow Sediments of the Pearl River Estuary, Southern China

Marine subsurface sediments represent a novel archaeal biosphere with unknown physiology. To get to know the composition and ecological roles of the archaeal communities within the sediments of the Pearl River Estuary, Southern China, the diversity and vertical distribution of active archaea in a sediment core were characterized by 16S rRNA phylogenetic analysis of clone libraries derived from RNA. In this study, the archaeal diversity above, within, and beneath the sulfate-methane transition zone (SMTZ) in the Pearl River Estuary sediment core was described. The majority of the clones obtained from the metabolically active fraction of the archaeal community were most closely related to miscellaneous crenarchaeotal group and terrestrial miscellaneous euryarchaeotal group. Notably, although the Pearl River Estuary sediment belong to high methane and high organic carbon environment, sequences affiliated with methanotrophic and methanogenic archaea were detected as minor group in 16S rRNA clone libraries. No obvious evidence suggested that these unknown archaeal phylotypes related directly to anaerobic oxidation of methane in SMTZ. This is the first phylogenetic analysis of the metabolically active fraction of the archaeal community in the coastal sediment environments.     

Molecular Fingerprint and Dominant Environmental Factors of Nitrite-Dependent Anaerobic Methane-Oxidizing Bacteria in Sediments from the Yellow River Estuary,China

Nitrite-dependent anaerobic methane oxidation (n-damo) is performed by “Candidatus Methylomirabilis oxyfera” (M. oxyfera), which connects the carbon and nitrogen global nutrient cycles. In the present study, M. oxyfera-like bacteria sequences were successfully recovered from Yellow River Estuary sediments using specific primers for 16S rRNA and pmoA genes. A M. oxyfera-like sequences analysis based on the 16S rRNA gene revealed greater diversity compared with the pmoA gene; the 16S rRNA gene sequences retrieved from the Yellow River Estuary sediments belong to groups A as well as B and were mainly found in freshwater habitats. Quantitative PCR showed that 16S rRNA gene abundance varied from 9.28±0.11×10³ to 2.10±0.13×10⁵ copies g^-1 (dry weight), and the pmoA gene abundance ranged from 8.63±0.50×10³ to 1.83±0.18×10⁵ copies g^-1 (dry weight). A correlation analysis showed that the total organic carbon (TOC) and ammonium (NH₄ ⁺) as well as the ratio of total phosphorus to total nitrogen (TP/TN) influenced the M. oxyfera-like bacteria distribution in the Yellow River Estuary sediments. These findings will aid in understanding the n-damo bacterial distribution pattern as well as their correlation with surrounding environmental factors in temperate estuarine ecosystems.