Hydrocarbons and heavy metals fixed to the lift station sediment of the Paris combined sewer network.

This work aims to characterise the pollutant loads fixed to the Lift Station (LS) sediments. Firstly, levels of n-alkanes, PAH and heavy metals (Fe, Zn, Cu, Pb and Cd) of LS sediments were assessed, and were found of the same order of magnitude as those reported for street runoff. In addition, investigations on LS sediment reveal that n-alkane distributions reflect the combination of biologic and petrogenic inputs, while PAH distributions indicate a major pyrolytic origin with traces of petrogenic contaminations. The metallic fingerprints also attest to the important contribution of road traffic emissions. Secondly, a comparison between LS sediment and the Gross Bed Sediment (GBS) pollutant contamination was established in order to optimize the in-sewer deposits management. For hydrocarbons, a similar contamination between both sediments is found. For the heavy metals, this comparison indicates a similar Fe and Zn content, while Pb, Cu and Cd contents differ. Indeed, LS sediment shows a higher Cu content, linked to the occurrence of intensive brake lining abrasion, compared with GBS, which reflects a higher Pb and Cd content, owing to the contribution of roof runoff. This result reveals the impact of specific inputs such as road traffic or roof runoff on the in-sewer sediments contamination, and provides a complete overview of the LS sediment contamination. This database could be used by the municipality to optimize their contaminated in-sewer sediment management.     

A novel method for evaluating bioavailability of polycyclic aromatic hydrocarbons in sediments of an urban stream.

Hydrophobic organic pollutants in urban wet weather discharges can accumulate in the sediments of receiving waters and may have adverse effects on the ecological system, especially on benthic organisms. Here, a novel method is developed for evaluating the bioavailability of such hydrophobic organic pollutants by considering the digestive guts in deposit-feeding polychaetes. We compared the amount of polycyclic aromatic hydrocarbons (PAHs) extracted by an organic solvent and by sodium dodecyl sulfate (SDS) solution (as a hypothetical digestive gut fluid of polychaetes) and interpreted the ratio of the two values as bioavailability. The sediment extracts were applied to bacterial acute toxicity tests and algal growth inhibition tests. Sediment samples were collected from an urban stream system receiving wet weather discharges. The bioavailability of the total amount of 12 PAHs in the sediments was in the range 14-38% based on the results from the GC/MS determination of the two different extracts. Lower molecular PAHs showed higher bioavailability compared to the higher molecular ones. The sediment extracts were shown to be toxic towards both algae and bacteria. The SDS extracts showed similar or higher toxicity in the two biotests compared to the organic solvent extracts in spite of their lower PAHs content.     

海洋环境中多环芳烃的污染状况及源解析

综述了国内外海洋水体、沉积物和生物体中多环芳烃(PAHs)的污染现状,分析了海洋环境中PAHs的来源。结果发现,不同海域PAHs的质量浓度差别较大,海水中PAHs的最高质量浓度为34338.0 ng/L,最低为13.0 ng/L;海洋沉积物中PAHs的最高质量比为1670.0μg/g,最低为24.1 ng/g;近海工业的发展程度及都市化进程与海域环境中PAHs的浓度存在明显的正相关关系;贝类的PAHs浓度比其他生物体高;海洋环境中的PAHs主要来源于海上石油烃的污染和陆地污染源的干湿沉降。     

Removal of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge by anaerobic degradation.

Due to the hydrophobic nature of the polyaromatic hydrocarbons (PAHs) they are mostly bound to the sludge and escape aerobic treatment in a wastewater treatment plant. They therefore proceed directly to the anaerobic post treatment, terminate in the sludge, and can be released to the environment if land spreading is used. PAH degradation in anaerobic methanogenic systems has only recently been shown to occur. In this study we have assessed several factors of anaerobic PAH degradation by evaluating thermodynamic feasibility of degradation, assessing degradation at different temperatures, and investigating the enriched cultures using fluorescent in-situ hybridization (FISH). Thermodynamic calculations indicated that PAH degradation was possible under methanogenic conditions, in the presence of hydrogen utilizing methanogens. Removal of naphthalene and 1-methyl naphthalene depended both on temperature and the initial inoculum. Inocula sourced from contaminated land sites were the most effective. The enrichments were all a mixture of Bacteria, and Archaea, and the Archaea were generally identified as Methanobacteriales, using an order-specific probe. The bacteria were not specifically identified. The results indicate a syntrophic culture, with the bacteria oxidizing the naphthalene, and the Archaea converting the hydrogen produced by oxidation, to methane.     

海河流域典型河流沉积物粒度特征及分布规律

为了解海河流域典型河流沉积物粒度参数空间分布规律,对海河典型河流的表层沉积物进行采集并利用Mstersize2000激光粒度仪进行粒度分析。结果表明,海河典型河流沉积物平均粒径差异显著,分选状况总体较差;山区水系与平原水系相比,沉积物平均粒径减小,呈集中分布,水动力减弱;山区自北向南变化明显,水系沉积物平均粒径减小,分布集中化,分选状况变差,由极正偏-正偏,向对称方向变化,峰度向平坦方向趋近,水动力减弱,符合粒径自然变化规律;平原区水系沉积物粒径参数表明南北变化不明显,因受较多支流、河流-湖泊-洼淀湿地等复杂系统和人为干扰强烈的影响,南北无显著变化规律。总的来说,海河流域河流受人为干扰强度较大,河流沉积物源较为复杂,栖息地物理完整性差。     

Investigating the effect of storm events on the particle size distribution in a combined sewer simulator.

The changes in particle size of sewer sediment particles rapidly eroded from a previously deposited sediment bed are described, using a rotating annular flume as a laboratory scale sewer simulator. This is the first time that particle size distributions of eroded sewer sediments from a previously deposited sediment bed have been monitored in such a controlled experimental environment. Sediments from Loenen, The Netherlands and Dundee, UK were used to form deposits in the base of the annular flume (WL Delft Netherlands) with varying conditions for consolidation in order to investigate the effect of changing consolidation time, temperature and sediment type on the amount and size of particles eroded from a bed under conditions of increasing shear. The median size of the eroded particles did not change significantly with temperature, although the eroded suspended solids concentration was greater for the higher temperature under the same shear stresses, indicating a weaker bed deposit. An increase in consolidation time caused an increase in median size of eroded solids at higher bed shear stresses, and this was accompanied by higher suspended solids concentrations. As the shear stress increased, the solids eroded from the bed developed under a longer consolidation time (56 hours) tended towards a broad unimodal distribution, whilst the size distribution of solids eroded from beds developed under shorter consolidation times (18 or 42 hours) retained a bi- or tri-modal distribution. Using different types of sediment in the flume had a marked effect on the size of particles eroded.     

多孔介质中多环芳烃与细菌共运移数值模拟

地下水中微生物等胶体对多环芳烃的运移具有促进作用,为进行多环芳烃污染的精准、高效修复,需要建立准确、可靠的多环芳烃与细菌胶体共运移数值模拟模型。研究基于室内砂柱荧蒽运移系列实验,采用Hydrus中Colloid-Facilitated Solute Transport（C-Ride）模块构建荧蒽与细菌FA1共运移数值模型,并采用马尔科夫链蒙特卡洛方法（Markov Chain Monte Carlo, MCMC）进行模型参数不确定性分析,定量刻画荧蒽在水动力和微生物胶体作用下的运移过程。结果表明：基于Hydrus C-Ride模块和MCMC参数不确定性分析,能够准确地刻画荧蒽和细菌FA1的共运移过程;细菌FA1促进了荧蒽在多孔介质中的迁移速度,且导致荧蒽在多孔介质中运移回收率的增加,即由55.06%提升至76.16%,其中吸附至可移动胶体迁移和随水流迁移贡献的回收率分别为41.46%、34.69%。研究成果对于指导地下水污染微生物修复方案的优化设计具有重要的理论和现实意义。     

Elimination and accumulation of polycyclic aromatic hydrocarbons in urban stormwater wet detention ponds

The concentrations of polycyclic aromatic hydrocarbons (PAHS) in water and sediments of seven wet detention ponds receiving urban stormwater were investigated. The ponds comprised traditional wet detention ponds with a permanent wet volume and a storage volume as well as ponds that were expanded with sand filters and other means to improve the removal of micropollutants. The concentrations of sigmaPAH in the sediments varied between 6 +/- 5 and 2,222 +/- 603 ng g(-1) dry weight (mean +/- standard deviation), and were highest in the ponds with lower pond volume per catchment area and did not clearly reflect different activities in the catchments. In general, the concentrations of PAHS in the sediments decreased from inlet to outlet, especially in the systems with good conditions for sedimentation such as systems with flow perpendicular sand dikes and extensive submerged vegetation. High molecular weight PAHs were predominant in the sediments indicating the pyrogenic origin of the PAHS. There was no correlation between PAH species concentrations in water or sediments and their hydrophobicity (log K(ow)). PAH concentrations in water fluctuated in response to intensity and frequency of rain events, whereas concentrations in the sediments integrated the pollutant load over time. Pond systems expanded with sand filters and other technologies to enhance removal of micropollutants consistently had concentrations of PAHS in the effluents below the detection level.     

Baseline assessment of metals and hydrocarbons in the sediments of Lake Mulwala, Australia

An assessment of hydrocarbon and metal/metalloids (arsenic, cadmium, copper, lead, mercury, selenium, zinc) contamination in sediments from Lake Mulwala, Australia, was undertaken. The objectives of the study were: (i) to determine the extent of contamination in the lake sediments, compared to Australian and international sediment quality guidelines, and (ii) to attempt to identify the contaminant sources to the lake. With the exception of a few samples containing elevated levels of arsenic and/or mercury, the levels of all contaminants in the sediment samples taken from the lake were below the ‘lower trigger’ of the Australian Sediment Quality Guidelines that would warrant further investigation. High molecular weight hydrocarbons (up to 700 mg kg⁻¹) were found in most sediment samples. Non‐metric statistical analysis indicated that the contaminant distribution was different in different parts of the lake, with the lowest concentrations generally found at the influent to the lake. No definitive source(s) of contamination could be identified for either metalloids or hydrocarbons.     

Distribution, sources and ecological risks of polycyclic aromatic hydrocarbons in an urban landscape river

The contents of 16 priority water-borne polycyclic aromatic hydrocarbons (PAHs) in water, potential external pollution sources and sediment from the famous landscape of the Qinghuai River were measured by gas chromatography-mass spectrometry (GC-MS). The distribution, composition, source and ecological risk of PAHs were analyzed. The following results were obtained: (1) Benzo[a]pyrene and benzo[ghi] perylene were not detected in all samples. The total contents of 16 priority PAHs (PAH16) varied from 52.5 to 745.3 ng l(-1) with the average of 174.0 ng l(-1) in water, from 96.0 to 1,064.6 ng l(-1) with the average of 329.2 ng l(-1) in potential sources, from 931.7 to 15,295.5 ng g(-1) with the average of 7,133.6 ng g(-1) in sediments. (2) The concentration of PAH16 in water is lower than in sediment and higher rings are more easily detected in sediment. The percentage of higher ring (four- to six-rings) PAHs accounted for more than 55.6% of PAHs in sediment. (3) The value of FLA/(FLA+Pyr) was higher than 0.5 at most sampling points which illustrated the source was related with petrogenic such as liquid fossil fuel combustion. (4) The potential ecosystem risk of low ring PAH for upstream conflux of external Qinhuai River was less than 10%, while it was 10-50% for other sampling points; The four rings PAH shows lower potential ecosystem risk than other ring PAH in this study area; Dibenzo [ah] anthracene (DahA) shows high potential ecosystem risk at all sampling points.     

An integrated assessment of polycyclic aromatic hydrocarbons (PAHs) and benthic macroinvertebrate communities in Isle Royale National Park

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants that are known carcinogens and mutagens. This research used the sediment quality triad, an integrated weight-of-evidence approach, to evaluate sediment PAH concentrations, sediment toxicity, and benthic community structure at marina and reference sites in Isle Royale National Park, USA. The highest PAH concentrations were measured at marina locations and exceeded threshold effect concentrations (161 μg PAH/g TOC) at one site. Marina locations were dominated by pyrogenic PAHs, indicating anthropogenic sources of these compounds. Survival of the amphipod Hyalella azteca was significantly reduced (p = 0.0320) when exposed to sediments from marinas. Although macroinvertebrate abundance and species richness were similar at marina and reference sites, results of multivariate analyses showed that composition of benthic communities varied among sites. In particular, abundance of the PAH-sensitive amphipod, Diporeia spp. was significantly lower at marina sites compared to reference sites. In contrast to patterns observed for organochlorines (e.g., PCBS, dioxins), biota-sediment accumulation factors for PAHs measured in the burrowing mayfly Hexagenia limbata decreased with increasing K_ow values, suggesting that the more lipophilic compounds were being metabolized. Increased PAH concentrations, shifts in community composition, low survival of H. azteca, and reduced abundances of Diporeia spp. at marina sites were consistent with the hypothesis that PAHs impacted these areas; however, across all sites these effects were relatively subtle. These results emphasize the need to use a weight-of-evidence approach when investigating effects of environmental contaminants that occur at relatively low concentrations.     

常规水处理工艺多环芳烃和邻苯二甲酸酯变化分布

以多环芳烃(PAHs)(包括萘、蒽、荧蒽三种物质)和邻苯二甲酸酯(PAEs)(包括邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二异丁酯(DIBP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)4种物质)作为研究对象,采用GC-MS方法测定了以长江为原水的某大型城市给水厂各工艺段水样中的上述物质.结果表明,7种物质均有检出,但含量均在纳克级,两种常规的水处理工艺对PAHs的控制有一定的效果,对PAEs的控制作用则相当有限.滤后水经加氯消毒、二次加压等工序后,水中的PAHs和PAEs略有增加.     

Sorption of polycyclic aromatic hydrocarbons into liposomes (artificial cell membranes) and the effects of dissolved natural organic matter

Dissolved natural organic matter (NOM) occurs widely in the aquatic environment and affects the fate of microorganic pollutants (e.g. intake, accumulation, movement, degradation, toxicity). The effect of NOM on the intake into biota (living cells) is very important. In the present study, the effects of coexisting NOM on the intake of microorganic pollutants into aquatic biota were experimentally evaluated. The NOM was concentrated from Lake Biwa water using a reverse osmosis filtration membrane. Two polycyclic aromatic hydrocarbons (PAH; pyrene and phenanthrene) were used as representative microorganic pollutants. Liposomes were synthesized in the laboratory to simulate living cell membranes and were used to investigate the intake of microorganic pollutants into aquatic biota. The experimental results (PAH onto NOM, NOM into liposomes, and PAH into liposomes) indicated that the sorption of PAH into liposomes was suppressed, apparently by PAH binding with NOM in the aqueous phase. This suggests that the accumulation and/or toxicity of microorganic pollutants can be retarded by NOM in the aqueous environment. Moreover, the experimental results indicated that sorption into liposomes (the liposome/water sorption coefficient, K_lipw) could be a better parameter for estimating the intake of microorganic pollutants into aquatic biota than the n-octanol/water partition coefficient (K_ow) in the aqueous environment.     

Development of extraction procedures for the analysis of polycyclic aromatic hydrocarbons and organochlorine pesticides in municipal sewage sludge.

Land application of sludge as fertilizers is a way of disposal and recycling of sludge. However, public concern has arisen due to the fact that organic contaminants in sludge may ultimately enter the food chain. Hence the need arises to analyse the organic contaminants such as PAHs and OCPs in sludge. In this study, Soxhlet was utilised as the extraction method and the extracts subjected to extensive cleanup via either silica columns or solid phase extraction cartridges prior to analysis using gas chromatography or high performance liquid chromatography. Sludge samples were collected from the drying beds of oxidation ponds in three locations in South Johore. OCPs such as heptachlor, dieldrin and pp-DDT were detected in low amounts (52-159 mg/kg) whereas PAHs such as naphthalene, phenanthrene, fluoranthene and benzo(a)pyrene were detected in the range of 0.2-5.5 mg/kg dry mass. Subcritical water extraction (SWE) recovery studies of PAHs were also performed from spiked sludge samples. Although a recovery range of 41-68% was obtained using the SWE method, the results indicated the usefulness of the technique as an alternative to Soxhlet extraction for the analysis of PAHs in sludge samples.     

烟台套子湾海域表层沉积物粒度分布特征及其动力响应

根据2010年10月采集的山东烟台套子湾大范围表层沉积物样品以及收集到的实测水文资料,分析研究套子湾海域表层沉积物的粒度分布特征,同时在应用GSTA模型对沉积物进行输运趋势分析的基础上,探讨该区域泥沙运移趋势.结果表明:整个套子湾内主要以细砂或极细砂和粉砂质砂为主,沉积物总体呈条带状分布向外逐渐变细;海区大部分区域的表层沉积物分选性都很好,相对与较小的潮流动力而言,波浪动力因素对泥沙的长期分选起到了主要作用;套子湾海域沉积物内细颗粒含量很少,平均值仅在3.49％,该海域细颗粒泥沙来源少,揭示了套子湾海域以波浪作用为主的沉积环境.应用GSTA模型对表层沉积物运移趋势分析结果显示,套子湾海域以垂直岸线横向输沙为主,近岸存在一定的纵向输沙,但强度不大,在优势浪垂岸入射和横向输沙作用控制下,纵向输沙强度较弱.     

Characterization and evaluation of potential reuse options for wastewater sludge and combined sewer system sediments in Mexico.

Combined sewer systems generate sediments that have characteristics similar to those of primary sludge. Mexico City has such a system composed of a network of pipes, regulation structures (dams, basins) and open channels. The annual generation of sediments is estimated at 2.8 Mm3, which includes 0.41 Mm3 of sludge. As a result, the total capacity for transporting water is reduced considerably, making it necessary to extract yearly an approximate 0.85 Mm3 of those materials and to send them to a final disposal site with a capacity that is being exhausted. As part of the local Governmental effort, this project evaluates the quality of sediments from 6 dams, 4 regulation basins, 2 open channels, and 3 transfer stations. Also, sludge from 20 wastewater treatment plants was sampled. The results showed an important presence of lead and hydrocarbons in some sediments, and some sludge samples contained arsenic and nickel above the limits. Moreover, microbial levels exceeded the limits in all the sediments and sludge samples. Erosion was linked to the generation of an important amount of sediments based on lead concentration. A classification was established to determine the degree of contamination of the sediments as well as the required treatment to allow their potential reuse.     

High performance liquid chromatography-tandem mass spectrometry for rapid and sensitive analysis of six polycyclic aromatic hydrocarbons in wastewater

A sensitive and fast method was developed to quantitatively analyse the six polycyclic aromatic hydrocarbons (fluoranthene (FLT), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a] pyrene (Bap), benzo[ghi]perylene (BghiP) and indeno[1,2,3-cd]pyrene (INPY)) by high performance liquid chromatography (UPLC) coupling with tandem mass spectrometry (MS/MS). Chromatographic separation was performed on a Waters Acquity UPLC BEHC18 column (1.7 microm, 2.1 mm x 50 mm). A 0.2 microm precolumn filter was used to protect the analytical column. Mobile phase Awas acetonitrile containing 0.5% toluene. Mobile phase B was water. Linearity of detection was in the range of 1-100 microg L(-1); LOD of 5 PAHs were lower than 0.1 microg L(-1); LOQ were 0.2 microg L(-1) except for benzo[k]fluoranthene. The LOD and the LOQ of benzo[k]fluoranthene were respectively 0.1 microg L(-1) and 0.8 microg L(-1). Wastewater samples collected from two wastewater treatment plants were determined using this method respectively. Recovery of all compounds varied from 67.8 +/- 10.6% to 113.2 +/- 7.2%. In comparison with the existing methods, this rapid method saves time and solvent and improves instrument sample throughput by 2-5 fold.     

南四湖表层底泥重金属空间分布及污染程度评价

测试南四湖湖区29个表层底泥中重金属Hg、Cd、Cr、Pb、Ni、Cu、Zn和类金属As的质量比,得到南四湖湖区重金属污染的空间分布特征。结合地质积累指数法和潜在生态风险指数法,对南四湖重金属污染程度进行评价。结果表明,南四湖已受到重金属元素的污染,属于中等程度污染湖泊,其中以As、Hg、Cd、Pb元素污染严重。除了As、Cd元素在下级湖表层底泥中的质量比略高外,其他重金属元素在上级湖的污染程度普遍比在下级湖的高;二级坝以北的昭阳湖湖区潜在生态危害最为严重,其次是南阳湖、微山湖、独山湖和二级坝以南的昭阳湖湖区。     

Phosphate and arsenate retention in sediments of the Anllóns river (northwest Spain).

We have studied the distribution and sorption behavior of phosphate and arsenate in bed-sediments of the Anllóns river (NW Spain). As a consequence of the intense gold-mining activity in the past, substantial amounts of arsenic were found in the river sediments. For phosphorus, higher concentrations were found near two sources of P pollution. Sorption isotherms were described by the Freundlich, Langmuir and Tempkin equations. In general, the sediments sorbed more P than As. The equilibrium P concentration (EPC) reveals that sediments act as a scavenger for soluble P; by contrast, equilibrium As concentration (EAC) values were high for the As-rich sediments and correlates well with total arsenic content. Amorphous Fe oxides content, organic matter and fraction of clay plus silt were the main properties of the sediments related with the sorption of arsenate and phosphate. The results obtained provide a first estimate of the sorption behavior and availability of the phosphate and arsenate anions in the sediments of the Anllóns river.