Polybrominated diphenyl ethers (PBDEs) are persistent flame retardants widely used in everyday materials, with the potential to leach out and contaminate indoors and receiving waters. Despite their well-documented ecological risks, there has been limited reporting on PBDE levels in sediments from Brazilian freshwaters, motivating the monitoring of sediments from Paranoá Lake, in the Brazilian capital. After sampling, extraction, and analysis of congeners BDE-28, -47, -66, -85, -99, -100, -138, -153, and -154 by gas chromatography with electron capture detection, Σ9PBDE levels ranged from 3.9 ± 0.2 to 19 ± 1 ng g-1 dw, with higher concentrations attributed to effluent discharge from wastewater treatment plants (WWTPs), followed by the influence of storm drainage water contamination. The distribution of PBDE congeners suggested a predominant influence of the commercial pentaBDE formulation, likely DE-71. However, in points influenced by WWTPs, the prevalence of BDE-66 suggests biotic reductive debromination of high-brominated PBDE, possibly BDE-209, indicating the possible influence of the decabrominated formulation. The distribution of PBDEs in the environment, estimated using the EQC (equilibrium criterion) model, level I, indicated low concentrations in the water column, but also noteworthy levels in biota and sediment precursor materials. Finally, preliminary ecological risk assessment indicated the need for future further surveys. (PBDEs materials waters welldocumented well documented risks freshwaters Lake capital sampling extraction BDE28, BDE28 BDE 28, 28 BDE-28 47, 47 -47 66, 66 -66 85, 85 -85 99, 99 -99 100, 100 -100 138, 138 -138 153, 153 -153 154 -15 detection ΣPBDE Σ 39 3 9 3. 02 0 2 0. g1 g g- dw WWTPs , (WWTPs) contamination formulation DE71. DE71 DE 71. 71 DE-71 However BDE66 BDE-6 highbrominated high brominated BDE209, BDE209 209, 209 BDE-209 environment equilibrium criterion model I column Finally surveys BDE2 BDE-2 4 -4 6 -6 8 -8 -9 10 -10 13 -13 15 -1 (WWTPs DE7 7 DE-7 BDE6 BDE- BDE20 20 BDE-20 - DE-

The Ipojuca River is considered the third most polluted river in Brazil due to the intense anthropogenic activities in the surrounding urban areas. The most important effluent is sewage discharge, which is responsible for considerable contamination. Traditional analyses (infrared spectroscopy, organic matter (OM), elemental analysis and granulometry) and advanced analysis of sterols by liquid chromatography-tandem mass spectrometry (LC-MS/MS) were applied to evaluate the levels of urban contamination from sewage in 10 surface sediment samples from the Ipojuca River, in a stretch located in the Caruaru city, Pernambuco, Brazil. The results pointed to sandy sediments, rich in OM from anthropogenic sources (predominant). Eight different sterols were detected with a total concentration in a range between < limit of quantification (LOQ) and 1,634.4 µg g−1. Coprostanol (fecal biomarker) was detected in high concentrations (557.3 µg g−1) in the sediment collected close to an open-air market (considered the largest in the world), making it the most contaminated in the region. Multivariate statistical analysis revealed areas tending towards contamination and that 90% of sediments were contaminated by sewage. These results can be considered useful for preventive and remedial actions toward promoting human health in this region.

ABSTRACT The drainage performance of a mesh filter determines the water consumption degree of the filter and the efficiency of the next work cycle. Through analysis, we found that the influent flow rate and the sediment content of the influent were important influencing factors. This experiment focused on the drainage time, pressure difference, and cleanliness to investigate the drainage performance of a new type of flap filter. The results showed that with increasing inlet flow rates, the time to discharge the effluent decreased, and the time required for the difference between the primary and secondary sewage pressures to reach a constant level was shorter. The cleanliness and drainage effects were improved. To verify this, we established mathematical models of sewage discharge time, sewage pressure difference, and sewage cleanliness based on the mass conservation law. The results showed that the relative error between the fitting calculation results and the experimental results was small, and the formula fit was over 95%. In the actual work, to achieve efficient sewage discharge under the condition of low sewage discharge and low water consumption, the discharge flow rate was set to 180 m³ h-1, and the sewage discharge time was set to 50 s. Under this condition, the sewage cleanliness reached above 97%.

Roadway sediment and stormwater runoff were sampled from a 15 km section of the R300 freeway located in the greater Cape Town area, South Africa. Grab samples were collected over a four-month period in 2016 and analysed for metals, hydrocarbons and nutrients. The metal concentration profiles were similar in sediment and runoff samples. The primary pollutants identified in the highway runoff were aluminium, copper, lead, manganese, nitrogen, phosphorus, zinc, total suspended solids (TSS), and oil and grease. The concentrations of each of these elements, barring lead, exceeded the national effluent water quality guidelines. Large volumes of macro pollutants such as cigarettes, plastic and packaging were also observed. The results of this research indicate that Sustainable Drainage Systems (SuDS) should be used in conjunction with highways, particularly where runoff may influence a sensitive or valuable aquatic ecosystem, as it can be a significant non-point source of pollution.

Abstract. The soft-bottom macrobenthos of Bahía San Julián intertidal was surveyed to identify infaunal assemblages and analyze their relationships with the main environmental factors determining species distribution. Four seasonal surveys (summer, autumn, winter and spring) were performed in the middle and lower intertidal levels at seven sampling stations established on both sides of the sewage discharge point, and water and sediment variables were measured. To explore possible spatial variations in the community, environmental and biological data were analyzed using univariate and multivariate statistics. Community composition varied with intertidal level, sediment characteristics and distance to sewage discharge site. In sediment with high mud content, the community was characterized by Darina solenoides, Mysella patagona, Eteone sculpta, Scolecolepides uncinatus and Capitella sp., in the middle intertidal, and was characterized by M. patagona and Ampelisca sp. in the lower intertidal. In sediment with dominance of fine sand, the community was characterized by Aricidea sp. at both intertidal levels. Near the effluent discharge site, the community was largely dominated by M. patagona. Intertidal level and sediment particle size are the main factors determining the composition of benthic assemblages in the study area. Sewage discharge also affects the composition of the infaunal community, possibly as a result of the contribution of particulate organic matter in suspension that stimulates the populations of detritus feeders.

Resumen. El macrobentos intermareal de fondos blandos de Bahía San Julián fue estudiado para identificar las asociaciones infaunales y para analizar su relación con los principales factores ambientales que determinan la distribución de las especies. Se realizaron 4 muestreos estacionales (verano, otoño, invierno y primavera) en los niveles intermareales medio e inferior en 7 estaciones de muestreo establecidas a ambos lados de un sitio de descarga de efluentes urbanos, y se midieron variables del agua y del sedimento. Para explorar las posibles variaciones espaciales en la comunidad, se analizaron los datos ambientales y biológicos utilizando estadística univariada y multivariada. La composición de la comunidad varió con el nivel intermareal, las características del sedimento y la distancia al sitio de descarga de efluentes. En sedimento con alto contenido de fango, la comunidad estuvo caracterizada por Darina solenoides, Mysella patagona, Eteone sculpta, Scolecolepides uncinatus y Capitella sp., en el intermareal medio, y por M. patagona y Ampelisca sp. en el intermareal inferior. En sedimentos con predominio de arena fina, la comunidad estuvo caracterizada por Aricidea sp. en ambos niveles intermareales. Próximo al sitio de descarga de efluentes, la comunidad estuvo ampliamente dominada por M. patagona. El nivel intermareal y el tamaño de partícula del sedimento son los principales factores determinantes de la composición de las asociaciones bentónicas en el área de estudio. El vertido de efluentes también afecta la composición de la comunidad infaunal, posiblemente como resultado del aporte de materia orgánica particulada en suspensión, que estimula a las poblaciones de organismos detritívoros.

Organochlorine pesticides (OCPs) were analysed in surface water, pore water and surface sediment samples collected from the uMngeni River, which is one of the largest rivers in the province of KwaZulu-Natal, South Africa. Liquid-liquid extraction was used to extract the analytes from water and pore water samples and soxhlet extraction was used to extract sediment samples with subsequent florisil clean-up and gas chromatography-mass spectrometry (GC-MS) analysis. Twelve selected OCPs were analysed and their total concentrations were found to range from 8.04-21.06 ng/mL, 36.06-188.43 ng/mL and 148.17-554.73 ng/g in unfiltered surface water, unfiltered pore water and surface sediment (dry weight (dw)), respectively. The results indicated that the concentrations of these selected pesticides were far higher in sediment (72%) than in pore water (25%) and water (3%). The most polluted sites were Northern Wastewater Treatment influent (NWTI) for water (Z12OCP = 19.41 ± 1.43 ng/mL) and Northern Wastewater Treatment effluent (NWTE) for pore water (Σ12 OCP = 166.23 ± 7.16 ng/mL) and sediment (Σ12 OCP = 495.21 ± 32.38 ng/g). The most abundant individual OCPs and their average concentrations in general in the river were p,p′-DDE in unfiltered water (1.62 ±0.22 ng/mL) and unfiltered sediment pore water (17.09 ±7.96 ng/mL), and endrin in surface sediment (55.57 ± 19.01 ng/g, dw).

Abstract Microbial fuel cells (MFC) are electrochemical devices that utilize the ability of some microorganisms to oxidize organic matter and transfer electrons resulting from their metabolism to an insoluble acceptor. The goal of the present study was to model the kinetics of electrical current generation from an MFC inoculated with marine sediment. For this purpose, a differential equation system was used, including the Nernst-Monod relationship and Ohm's Law, to describe the microbial metabolism and the mechanism of extracellular electron transfer (EET), respectively. The experimental data obtained by cyclic voltammetry analysis were properly described by the model. It was concluded that marine microorganisms preferably use a direct mechanism of EET by means of nanowires to establish the electrochemical contact with the anode. The mathematical modeling could help understand MFC operation and, consequently, contribute to improving power generation from this source.

Arsenic and mercury are among the metals and metalloids more toxic to the ecosystem. A quantification method by atomic absorption spectroscopy with hydride generator (AAS-HG) to determine total As and cold steam to determine Hg was optimized and validated in various matrices: superficial water, interstitial or pore water, sediments and in gill, liver and muscle of two fish species, a silverside (Basilichthys microlepidotus) and a catfish (Trichomycterus areolatus). The quality of the results was tested using certified reference materials (Water: ERM-CA615; Fish: DOLT-4; Sediment: BCR-320R). Samples were collected in the affluent and effluent of five reservoirs: Cogotí (31°00’S, 71°05’W); Corrales (31°54°S, 70°54’W); La Paloma (30°44’S, 71°00’W); Rapel (34°08’S, 71°29’O); Recoleta (30°28’S, 71°06’W). ), in two campaigns during high flow (winter 2010) and low flow (summer 2011). The results show a clear difference in the distribution of As and Hg in the different matrices; higher concentrations were found in the order sediment > interstitial water > surface water. Catfish showed higher accumulation of both metals, and metal concentrations generally decreased in the order liver > gill > muscle. No significant effect of reservoirs and zones was observed in As and Hg content. However, Arsenic (As) was found in higher concentration in the different matrices of the five reservoirs and zones. The concentrations of As and Hg in all samples did not exceed international standards in the case of sediment and the Chilean norm in the case of water, while in both fish species concentrations of As and Hg in muscle exceeded international standards.

La Bahía de Pertigalete está bordeada de una extensa zona de manglares y se encuentra afectada por un intenso tráfico náutico, el vertido de aguas servidas procedente de poblaciones aledañas y los efluentes de la empresa Cementos de Venezuela. Este trabajo tuvo como objetivo determinar la actividad microbiana en sedimentos superficiales y el posible impacto antropogénico en zonas de manglar de la Bahía de Pertigalete durante los períodos de surgencia y transición. La biomasa microbiana, expresada en carbono de masa microbiana (Cmic), respiración basal (RB), actividad de las deshidrogenasas (DHS), hidrólisis del diacetato de fluoresceína (HDAF) y el cociente metabólico (qCO2) fueron empleados en la determinación de la actividad microbiana. En tres zonas de la bahía se establecieron tres transectos de 30 m de longitud, con una separación de 10 m. En cada transecto se situaron tres puntos de muestreo tomándose por triplicado muestras de sedimento superficial. Los resultados mostraron que durante el período de surgencia existe una mayor Cmic en las tres zonas seleccionadas: 851,01; 539,87; y 533,66 mg Cmic kg-1 sedimento en las zonas I, II y III respectivamente. La DHS indicó que existe un predominio de poblaciones heterotróficas anaeróbicas durante éste período. La HDAF confirmó que ocurre una mayor actividad heterotrófica durante la surgencia y el qCO2 reflejó mayor eficiencia en la utilización del carbono. Los resultados reflejan que la predominancia de la flora microbiana y su actividad en los sedimentos está determinada principalmente por las temporadas de surgencia y transición, especialmente en la zona I, la cual está menos expuesta a la acción antrópica.

The Pertigalete Bay is bordered by an extensive mangrove zone and it is affected by an intense boating and sailing traffic, the pouring of the waste water coming from the nearing population and effluent from the company Cements of Venezuela. The objective of this research was to determinate the microbial activity and the possible anthropogenic impact in surface sediments of mangrove zones in the Pertigalete Bay during the up welling and transition periods. The microbial biomass (Cmic), the basal respiration (RB), dehydrogenases activity (DHS), fluorescein diacetate hydrolysis (HDAF) and the metabolic quotient (qCO2) were used in the determination of the microbial activity. In three zones of the bay three transects of 30 m of length were established with a separation of 10 m among them. In each transect, three sampling points were placed and triplicate samples of the surface sediments were taken from each. The results showed that during the up welling period there is a higher Cmic in the three selected zones: 851.01; 539.87 and 533.66 mg Cmic kg-1 sediment in zones I, II and III, respectively. The DHS indicated that there is a predominance of the anaerobic heterotrophic population during this period. The HDAF confirmed that there is a higher heterotrophic activity during the up welling and the qCO2 indicated a greater efficiency in the use of carbon by the microorganism present in the sediments. The results showed that the predominance of the microbial flora and its activity in the sediments is mainly determined by the up welling and transition periods, especially in the zone I, which is less exposed to the anthropogenic action.

Impact of pollution on aquatic biota is usually assessed by comparing the assemblage at an impacted site with those at a control or reference site. In South Africa, except in rivers where not all biotopes are represented, the characterisation of a macroinvertebrate-based pollution effect is usually based on samples collected from three distinct biotopes, i.e., stones, vegetation and sediments. In this study, the influence of reducing the numbers of biotopes on chironomid-based bioassessment of pollution in the Swartkops River was investigated. This paper addresses the following questions: (i) can the chironomid species assemblage from any single distinct biotope analysed separately provide sufficiently accurate results similar to those of the composite-biotope group assemblage, and (ii) can chironomid community types be identified based on their biotope preferences? Chironomid larvae were sampled seasonally from three distinct biotopes: stones (stone-in-and-out-of-current), vegetation (marginal and aquatic), and sediment (gravel, sand and mud, GSM) at one upstream control site, i.e., Site 1, and three downstream sites, i.e., Sites 2, 3 and 4. Site 2 in Uitenhage was impacted by diffuse pollution sources including runoff from road networks. Site 3, also in Uitenhage, was impacted by wastewater effluent discharges as well as diffuse pollution sources, while Site 4 in Despatch was about 2.5 km downstream of Site 3. The multivariate analysis of similarity (ANOSIM) indicated that the chironomid species assemblages based on the composite biotopes were significantly different between all site pairs in terms of species composition and abundance. However, when the assemblages were analysed separately for each of the three distinct biotopes, only the stone-based assemblage indicated significant differences between all of the site pairs similarly to those of the composite biotopes. Thus, the results suggest that, when resources are limited, sampling only the stony benthos could still provide bioassessment results similar to benthos from all three biotopes combined.

The effect of shrimp aquaculture effluents on some environmental parameters of the receiving coastal waters was assessed. Water and sediment samples were taken at different distances from the discharge point (50, 150, and 300 m) when shrimp farms had ceased operations (survey 1), had initiated operations (survey 2), and during the early harvest (survey 3). Water and sediment samples were likewise taken at the same distances from the shore in a non-impacted area. During surveys 1 and 2, the effluents had a negative effect at all three distances (50, 150, and 300 m) on the water quality variables (transparency, seston [total suspended solids, total inorganic solids, particulate organic matter], chlorophyll a, N-NO2-, N-NO3-, N-NH4+), on the sediment quality parameters (organic nitrogen), and on the TRIX index. Contrarily, no differences were observed when the impacted and non-impacted areas were compared during survey 3, probably because the effluents had diminished due to the premature harvesting. The results suggest that at the end of the farming period, the nutrient and organic matter load exceeded the assimilation capacity of the ecosystem, whereas during the recess period, the environment was capable of assimilating the excess organic matter accumulated. The levels reached by the monitored parameters did not exceed the limits established and the impact on the ecosystem is not severe, but they could represent a risk factor in the long term. Additionally, there is evidence that the temporary suspension of shrimp farming operations is beneficial for the environment.

Se evaluó el efecto de las descargas de un parque acuícola sobre los parámetros ambientales de las aguas costeras receptoras. Se tomaron muestras de agua y sedimento del medio a diferentes distancias del punto de descarga (50, 150 y 300 m) cuando las granjas se encontraban al final del ciclo de cultivo (muestreo 1), durante la etapa de operación (muestreo 2) y durante la cosecha prematura de las granjas (muestreo 3). También se recolectaron muestras de agua y sedimento a las mismas distancias de la costa en una zona no impactada. Se observó que durante los muestreos 1 y 2, las descargas tenían un impacto negativo a todas las distancias (50, 150 y 300 m) sobre los parámetros de la calidad del agua (transparencia, concentración de seston [sólidos suspendidos totales, sólidos inorgánicos totales y materia orgánica particulada], clorofila a, N-NO2-, N-NO3-, N-NH4+), sobre los parámetros de la calidad del sedimento como nitrógeno total y sobre el índice TRIX. En contraste, no se observaron diferencias significativas al comparar la zona impactada con la no impactada durante el muestreo 3, quizás porque disminuyeron las descargas de aguas residuales casi en su totalidad debido al cierre prematuro de los cultivos. Los resultados sugieren que al final del ciclo de cultivo, la acumulación de nutrientes y materia orgánica rebasa la capacidad de asimilación del medio, mientras que durante el período de receso, el medio es capaz de asimilar el exceso de materia acumulada. Los niveles alcanzados por los parámetros monitoreados no exceden los límites máximos establecidos y el impacto sobre el medio no es severo, pero esto podría representar un factor de riesgo a largo plazo. Además, hay evidencia de que el receso en las operaciones de las granjas resulta benéfico para el medio.

Amostras de sedimento, água, mexilhão e peixe foram colhidos mensalmente durante um período de 19 meses em várias estações ao longo da margem norte do estuário do Tejo (Lisboa, Portugal). As amostras foram imediatamente analisadas para radionuclidos emissores gama, em especial para os de origem artificial. Entre estes, o 131I e 99mTc foram detectados na maioria das amostras de mexilhões (Mytilus galloprovincialis) e de taínha (Liza ramada). A distribuição espacial das amostras contendo esses radionuclidos indicou contaminação continuada em Alcântara e Praça do Comércio, e, nalgumas ocasiões, também em Chelas. Ao longo do ano, em geral não se detectou contaminação em Algés, na entrada do estuário, e em Beirolas na zona média do estuário cerca da Ponte Vasco da Gama, mas a contaminação radioactiva foi consistentemente detectada nas áreas que recebiam as descargas de águas residuais urbanas da cidade de Lisboa. Os radionuclidos 131I e 99mTc são utilizados em medicina nuclear e têm origem nos efluentes líquidos hospitalares descarregados no sistema de esgotos da cidade. A sua detecção junto à Praça do Comércio relacionou-se com as descargas do esgoto principal da Baixa de Lisboa que, nos anos da amostragem ainda descarregava naquela área águas residuais urbanas não tratadas. Perto de Alcântara, onde se localiza a descarga de águas residuais urbanas tratadas pela estação de tratamento (ETAR) de Alcântara, a detecção daqueles radionuclidos indicou que o tratamento de esgotos e o atraso introduzido na descarga dos efluentes tratados não foram suficientes para permitir o decaimento radioactivo. Os valores mais elevados de concentração de 131I e 99mTc foram 12±2 e 136±20 Bq Kg-1 peso fresco (p.f.) em mexilhões e peixes, respectivamente. Essas concentrações não excederam as concentrações de radionuclidos de origem natural, tais como o 40K que em média foram de 66±13 Bq Kg-1 (p.f.) em mexilhão e 618±21 Bq Kg-1 (p.f.) no peixe. No entanto, a acumulação dos radionuclidos artificiais nos organismos aquáticos aumenta a dose de radiação recebida por esses organismos e aumenta o risco de transferência dos radionuclidos artificiais para os seres humanos. A redução da radioactividade nas descargas de efluentes urbanos para melhorar a qualidade radiológica da água e sedimento do estuário é debatida como condição necessária para um uso sustentável do estuário.

Sediments, water, mussels and fish were collected monthly during a 19 month period at eight sampling stations along the North bank of the Tejo estuary (Lisboa, Portugal). Fresh samples were immediately analysed for short lived gamma emitting radionuclides. Amongst these, 131I and 99mTc were detected in most samples of mussels (Mytilus galloprovincialis) and mullets (Liza ramada). Spatial distribution of samples containing these radionuclides consistently indicated contamination at Alcântara and Praça do Comércio, and, on occasion, at Chelas, all sites inside the estuary. Round-the-year, generally there was no contamination at Algés, near the estuary mouth, and Beirolas, upstream by the Vasco da Gama Bridge. The estuarine areas found contaminated by radionuclides correspond to the areas receiving urban wastewater discharges from the city of Lisboa. The artificial radionuclides 131I and 99mTc are used in nuclear medicine practices and originate from hospital liquid effluent discharges into the city sewage system. Their presence near Praça do Comércio was related to the nearby discharges of a main sewer discharging untreated urban wastewater. Near Alcântara, the sewer outlet discharged treated urban wastewater from the Alcântara wastewater treatment plant and the presence of short-lived radionuclides indicated that sewage treatment and the time delay introduced before discharge of the treated effluent were not sufficient to allow for radioactive decay of those radionuclides. The highest concentration values of 131I and 99mTc determined in mussels and fish were 12±2 and 136±20 Bq Kg-1 wet weight (w.w.), respectively. These concentrations did not exceed the concentrations of naturally-occurring radionuclides, such as 40K that averaged 66±13 Bq Kg-1 (w.w.) in mussels and 618±21 Bq Kg-1 (w.w.) in fish. Nevertheless, artificial radionuclides accumulated in biota increase the radiation dose received by organisms from natural radiation sources and may also increase the risk of radionuclide transfer to humans. Reduction of radioactivity in effluent discharges towards improved estuarine water and sediment quality is debated as a requirement for sustainable use of the estuary.

A carcinicultura causa impactos ambientais significativos devidos, sobremaneira, à elevada demanda de água e ao descarte de efluentes, agravando o problema de assoreamento e poluição dos mananciais. Este trabalho teve como objetivo buscar uma alternativa para o reaproveitamento do efluente da carcinicultura na própria atividade e assim mitigar os impactos causados. Os experimentos foram realizados em três etapas, a primeira relacionada à toxicidade, para as pós-larvas das águas de despesca, a segunda com a mortalidade das pós-larvas em curto prazo e a terceira relacionada com a sobrevivência em longo prazo e produtividade do camarão ao longo de um ciclo de engorda, utilizando-se água de despesca. Os resultados mostraram que o índice de sobrevivência é de 42,1% quando o camarão é cultivado em águas de despesca; no entanto, a maior mortalidade dos camarões ocorre principalmente na primeira semana do ciclo de engorda, indicando que uma mudança de estratégia na produção de camarão pode aumentar a produtividade da fazenda.

The shrimp farming cause significant environmental impacts due to high water consumption and effluent discharge, which worsen problems of sediment deposition and water pollution. This study aims to find an alternative for the use of shrimp farming effluent, and to mitigate the aforementioned impacts. The experiments were carried out in three phases, where the first dealt with the toxicity of the reused effluent on the post-larvae of shrimp, the second dealt with the short term mortality of the shrimps and the third dealt with the long-term survival and productivity of the shrimps along the entire growing cycle. The results show that the survival index is 42.1% when the shrimps are cultivated in shrimp farm effluent. However, most of the mortality occurred within the first week of the growing cycle. This indicates that a change in production strategy can increase productivity of the farm.

A simple analytical procedure was developed for simultaneous determination of trace levels of tri- to hepta-BDEs as well as 2,2′,4,4′,5,5′-hexabromobiphenyl (BB 153). The mechanical shaking extraction technique for the isolation of target analytes was optimised. Different extraction solvent combinations were tested under different extraction time periods of 3, 6, 12 and 16 h. The n-hexane:acetone (2:1, v/v) combination gave the best recovery at the optimum extraction of 12 h. Target analytes were quantified using a high capillary gas chromatograph (GC) equipped with an electron capture detector. Under the optimum GC conditions, the resolution of the co-eluting BDE 154 and BB 153 was achieved. The overall recoveries of target analytes in the matrix spike experiment conducted ranged between 84.4 and 110% for BDE 183 and BDE 28, respectively. The method was applied to 19 field sediment samples collected from a control site and from 3 sampling locations (upstream, point of discharge and downstream) of the Black River, which receives effluent from a wastewater treatment plant (WWTP). The sum of the mean concentrations of all of the 7 PBDE congeners was 4.63, 0.35, 'not detectable' and 4.43 ng/g, for the control site, upstream, point of discharge and downstream samples, respectively. The concentrations of BB 153 were generally low in these samples and ranged between ND and 0.89 ng/g. The developed method allows for the simultaneous determination of PBDE congeners and BB 153. It is efficient, moderately rapid and cost-effective.

Os organismos bentônicos têm muitas propriedades úteis que os fazem organismos sentinelas em programas de biomonitoramento em ecossistemas de água doce. Analisando em conjunto com as características da água e do sedimento, são potenciais indicadores da qualidade ambiental. Neste contexto, a ocorrência espacial de metais pesados (Al, Zn, Cr, Co, Cu, Fe, Mn e Ni) na água, sedimentos e amostras de macroinvertebrados bentônicos foi investigada em uma sub-bacia no sudeste do Brasil, na cidade de São Carlos, SP, com o objetivo de verificar a interação dos metais do ambiente com a comunidade bentônica quanto à bioacumulação. Por hipótese, admite-se que haja contaminação por metais nos ambientes aquáticos do município devido à ausência de tratamento de efluentes industriais. Todas as amostras foram analisadas pelo método USEPA adaptado e processado por espectrofotômetro de absorção atômica. A bacia estudada apresenta contaminação por metais tóxicos em águas superficiais, sedimentos e macroinvertebrados bentônicos. O Fator de Bioacumulação mostrou uma tendência para a bioacumulação de metais por organismos bentônicos para quase todas as espécies de metal. Os resultados demonstram um potencial risco à saúde humana e ao ecossistema, contribuindo com o estudo de contaminação por metais em ambientes aquáticos de áreas urbanas.

Benthic macroinvertebrates have many useful properties that make possible the use of these organisms as sentinel in biomonitoring programmes in freshwater. Combined with the characteristics of the water and sediment, benthic macroinvertebrates are potential indicators of environmental quality. Thus, the spatial occurrence of potentially toxic metals (Al, Zn, Cr, Co, Cu, Fe, Mn and Ni) in the water, sediment and benthic macroinvertebrates samples were investigated in a sub-basin in the southeast of Brazil in the city of São Carlos, São Paulo state, with the aim of verifying the metals and environment interaction with benthic communities regarding bioaccumulation. Hypothetically, there can be contamination by metals in the aquatic environment in the city due to lack of industrial effluent treatment. All samples were analysed by the USEPA adapted method and processed in an atomic absorption spectrophotometer. The sub-basin studied is contaminated by toxic metals in superficial water, sediment and benthic macroinvertebrates. The Bioaccumulation Factor showed a tendency for metal bioaccumulation by the benthic organisms for almost all the metal species. The results show a potential human and ecosystem health risk, contributing to metal contamination studies in aquatic environments in urban areas.