Identifying potential uses for green roof discharge based on its physical-chemical-microbiological quality.

Green roofs are promising tools in sustainable urban planning, offering benefits such as stormwater management, energy savings, aesthetic appeal, and recreational spaces. They play a crucial role in creating sustainable and resilient cities, providing both environmental and economic advantages. Despite these benefits, concerns persist about their impact on water quality, especially for non-potable use, as conflicting results are found in the literature. This study presents a comparative analysis of the quantity and quality of water drained from an extensive green roof against an adjacent conventional rooftop made of fiber-cement tiles in subtropical Brazil. Over a 14-month period, the water drained from both roofs was evaluated based on physical (turbidity, apparent color, true color, electrical conductivity, total solids, total dissolved solids, suspended solids), chemical (pH, phosphate, total nitrogen, nitrate, nitrite, chlorides, sulfates, and BOD), microbiological (total coliforms and E. coli), and metal (copper, iron, zinc, lead, and chrome) concentration parameters. The discharge from the green roof was 40% lower than its counterpart measured at the control roof, while the water quality from both roofs was quite similar. However, the green roof acted as source of chlorides, electrical conductivity, color, BOD, total hardness, E. coli, phosphate, sulfate, and turbidity. On the other side, the green roof neutralized the slightly acidic character of rainwater, showcasing its potential to mitigate the effects of acid rain. The study's results underscored that the water discharged from the green roof generally aligned with non-potable standards mandated by both Brazilian and international regulations. However, the findings emphasized the imperative need for pre-treatment of the green roof discharge before its utilization, specifically adjusting parameters like turbidity, BOD, total coliforms, and E. coli, which were identified as crucial to ensure water safety and compliance with non-potable use standards.

Ecotoxicological response surface analysis of salt and pH in textile effluent on Bacillus subtilis and Lactuca sativa.

Textile effluents, although their composition can vary considerably, typically contain high levels of dissolved salts and exhibit wide variations in pH. Ecotoxicological studies regarding the effects of these parameters, however, have been limited owing to the need for sensitive and easy-to-handle bioindicators that require low amounts of sampling, are cost-effective, time-efficient, and ethically endorsed. This kind of study, additionally, demands robust multi-factorial statistical designs that can accurately characterize the individual and combined relationship between variables. In this research, Response Surface Methodology (RSM) was used to calculate the individual and interaction effects of NaCl concentration and pH value of a Simulated Textile Effluent (STE) on the development rate (DR) of the bioindicators: Bacillus subtilis bacteria and Lactuca sativa lettuce. The results demonstrated that the bioindicators were sensitive to both NaCl and pH factors, where the relative sensitivity relationship was B. subtilis > L. sativa. The quadratic equations generated in the experiments indicated that increased concentrations of 50-250 mg L-1 of NaCl caused a perturbance of 1.40%-34.40% on the DR of B. subtilis and 0.50%-12.30% on L. sativa. The pH factor at values of 3-11 caused an alteration of 27.00%-64.78% on the DR of the B. subtilis and 51.37%-37.37% on the L. sativa. These findings suggest that the selected bioindicators could serve as effective tools to assess the ecotoxicological effects of textile effluents on different ecological systems, and the RSM was an excellent tool to consider the ecotoxicological effects of the parameters and to describe the behavior of the results. In conclusion, the NaCl and pH factors may be responsible for disrupting different ecosystems, causing imbalances in their biodiversity and biomass. Before discharge or reuse, it is suggested to remove salts and neutralize pH from textile effluents and, mostly, develop novel, eco-friendlier textile processing techniques.

Antibiotic degradation and mineralization: efficiency increase on combining different chemical treatment processes.

The goal of this study was to assess the efficiency of antibiotic degradation applying different chemical treatment methods and their combinations. Thus, improvement in the efficiency of these methods when combined was quantified. The methods tested to degrade/mineralize the antibiotics amoxicillin (AMX) and ciprofloxacin (CIP) under different pH conditions (4, 7 and 10) were ultra-violet irradiation (UV254 nm), ultrasound (US), hydrogen peroxide (H2O2) and ozone (O3) alone and in combination. The results showed that individual methods were only partially efficient in the degradation/mineralization of antibiotics, except for ozonation at alkaline pH. In the combined methods, the best performance was obtained with US/UV/H2O2/O3 (pH 10, 20-min treatment), where the degradation rates for the antibiotics were 99.8% for CIP and 99.9% for AMX. For the mineralization efficiency the values obtained were 71.3% for CIP and 79.2% for AMX. The results of this study could contribute to the development and improvement of wastewater treatment aimed at avoiding the presence of residual antibiotics in the environment.

Reuse of iron ore tailings as an efficient adsorbent to remove dyes from aqueous solution.

In this work, an iron ore tailings sample (IOT), collected from a tailings dam in Minas Gerais, Brazil, was characterized. The IOT presented point of zero charge of ∼ 6, specific surface area of 4 m2 g-1, and was mainly composed of hematite and quartz. Subsequently, experiments were performed to evaluate the adsorption of an anionic dye, Direct Red 80 (DR80), and a cationic dye, Methylene Blue (MB), by the IOT, studying the effects of its dose (doseIOT) and the solution initial pH (pH0). The DR80 removal increased with the decrease of the pH0 while the opposite effect occurred in the experiments with the MB, suggesting the process is governed by the adsorption resulting from electrostatic forces. The increase in the doseIOT increased the DR80 and MB removal, which can be attributed to the greater availability of adsorption sites. Pseudo-second order kinetic (R2 > 0.9994) and the Langmuir equilibrium isotherm (R2 > 0.9842) models described well the DR80 adsorption by the IOT, being the reaction rate and maximum adsorption capacity higher at lower pH0. In a regeneration experiment, it was possible to desorb almost entirely the DR80 using a NaOH solution. Additionally, the regenerated IOT was able to adsorb the DR80, demonstrating its reusability. In a preliminary assay, the IOT decreased the colour of the textile wastewater sample at pH0 3. Therefore, the results indicate the potential use of IOT for removing electric-charged pollutants by adsorption, especially anionic ones under acidic conditions.

Estimating the urban environmental impact of gasoline-ethanol blended fuels in a passenger vehicle engine.

A large portion of urban emissions in developing countries come from old gasoline vehicles driven in metropolitan areas. The present study aimed to develop models to estimate the environmental impact of different contents of gasoline and ethanol mixtures (pure gasoline; 25, 50, 75% ethanol blended to gasoline; and 100% ethanol) in a flex-fuel engine. We tested the blended fuel using three different speeds and recorded the GHG emissions and engine output data. The data mining approach was used to develop environmental impact predictive models. The ethanol content in gasoline; the engine rotational speed 900, 2000, and 3000 rpm; and λ were used as attributes. The classification target was the environmental impact concerning the CO2 emission ("low," "average," and "high"). We employed the Random forest algorithm to develop predictive models. The mean values of CO2 concentrations for all studied fuel content were above 2.47% of the volume. The trees' models (accuracy 73%, κ =0.61) showed three alternatives for predicting the environmental impact based on the ethanol blend, the engine rotation, λ, and the air-fuel ratio. Such models might help policymakers develop educational campaigns to reduce short- and medium-term urban commuter traffic pollution in countries that lack suitable urban transportation.

Use of brewing industry waste to produce carbon-based adsorbents: Paracetamol adsorption study.

This work aimed to produce activated carbon (AC) from brewing industry waste (the malt bagasse) to adsorb Paracetamol. Malt bagasse was characterized by moisture and ash contents and thermogravimetric analysis. Three types of AC were prepared: C400 (400 °C) and C500 (500 °C) under oxidizing atmosphere, and CN550 (550 °C) under nitrogen atmosphere. Some of these ACs were characterized by pH, point of zero charge (pHPZC), infrared spectroscopy, N2 adsorption-desorption isotherms, scanning electron microscopy, and temperature-programed desorption of CO2 and NH3. A pHPZC value < 7.0 and high density of acid sites were identified for CN550. Specific surface areas were between 192.5 and 364.0 m2.g-1. Adsorption kinetic studies were performed in a batch system with 50 mL of Paracetamol solution (100 mg.L-1) under pH 4 and 0.75 g of adsorbent (optimized conditions). The time to reach adsorption equilibrium was 20 min with 98.3% Paracetamol removal for CN550 AC. The pseudo-second order model and the Langmuir isotherm best fitted experimental data. Brewing industry waste can be used as a source of organic matter for AC production, since the percentage of Paracetamol removal in this study showed that CN550 AC presentes high adsorption efficiency and economically viable production.

The 2016 red tide crisis in southern Chile: Possible influence of the mass oceanic dumping of dead salmons.

In 2016, a massive harmful algal bloom (HAB) of Alexandrium catenella around Chiloé island caused one of the major socio-ecological crisis in Chilean history. This red tide occurred in two distinct pulses, the second, most anomalous, bursting with extreme toxicity on the Pacific coast, weeks after the highly controversial dumping off Chiloé of 4,700 t of rotting salmons, killed by a previous HAB of Pseudochattonella verruculosa. We study the transport of this pollution, analyzing the physical oceanographic conditions during and after the dumping. We find that a cyclonic gyre was present between the dumping site and the coast, visible in satellite altimetry and sea surface temperature data. Using Lagrangian simulations, we confirm that near-surface currents could have brought part of the pollution to the coast, and fueled the bloom. This scenario explains also the anomalous later finding of ammonium near Chiloé. Finally we discuss the mismanagement of risk throughout the events.

Effect of photocatalytic Fe2O3 nanoparticles on urban runoff pollutant removal by permeable concrete.

Permeable pavements are an efficient urban runoff (UR) management solution that also improve water quality. In this work, a photocatalytic layer of Fe2O3 nanoparticles (NP) was incorporated into permeable concrete to evaluate its impact on the removal of several microbiological (Escherichia coli, Pseudomonas aeruginosa, Aeromonas hydrophila, and Enterococcus faecalis) and physicochemical (N-NH4+, N-NO3-, phenol, PO43-, Fe, Mn, and Pb) pollutants. First, permeable concrete samples were created with sufficient compressive strength and hydraulic conductivity for light traffic. The test samples were then coated with a mixture containing either 3% or 5% Fe2O3 NP by cement weight. Control samples were prepared without NP. Scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy analyses showed that the nanoparticles remained unaltered on the concrete's surface. Synthetic URs simulating the microbiological or physicochemical composition of real UR were applied to the samples to evaluate their pollutant removal efficiencies. The depollution performances of the test (with 3% and 5% Fe2O3 NP) and control samples were statistically compared. The test samples (3% NP, 5% NP, and the controls) significantly modified (p < 0.05) most of the measured variables (i.e., the concentrations of E. coli, A. hydrophila, PO43-, Fe, Mn, and Pb) in the synthetic URs. Unexpectedly, the test samples (with 3% or 5% Fe2O3 NP) did not significantly remove (p > 0.05) some pollutants prone to oxidation, such as phenol or ammonium. However, the 5% NP sample significantly enhanced Mn removal. In general, the decontamination performances of the concrete samples with Fe2O3 NP were not influenced by the nanoparticles; thus, they did not appear to add value to the generated permeable concrete. Nevertheless, our results indicate the considerable benefits of implementing permeable concrete to improve the quality of UR.

Health benefits and control costs of tightening particulate matter emissions standards for coal power plants - The case of Northeast Brazil.

Exposure to ambient particulate matter (PM) caused an estimated 4.2 million deaths worldwide in 2015. However, PM emission standards for power plants vary widely. To explore if the current levels of these standards are sufficiently stringent in a simple cost-benefit framework, we compared the health benefits (avoided monetized health costs) with the control costs of tightening PM emission standards for coal-fired power plants in Northeast (NE) Brazil, where ambient PM concentrations are below World Health Organization (WHO) guidelines. We considered three Brazilian PM10 (PMx refers to PM with a diameter under x micrometers) emission standards and a stricter U.S. EPA standard for recent power plants. Our integrated methodology simulates hourly electricity grid dispatch from utility-scale power plants, disperses the resulting PM2.5, and estimates selected human health impacts from PM2.5 exposure using the latest integrated exposure-response model. Since the emissions inventories required to model secondary PM are not available in our study area, we modeled only primary PM so our benefit estimates are conservative. We found that tightening existing PM10 emission standards yields health benefits that are over 60 times greater than emissions control costs in all the scenarios we considered. The monetary value of avoided hospital admissions alone is at least four times as large as the corresponding control costs. These results provide strong arguments for considering tightening PM emission standards for coal-fired power plants worldwide, including in regions that meet WHO guidelines and in developing countries.

Enrichment of population density of a bacterial consortium during bioremediation of a soil under successive contaminations with diesel oil / Enriquecimento da densidade populacional de um consórcio bacteriano durante a biorremediação de um solo sob sucessivas contaminações com óleo diesel

The effect of successive soil contamination with diesel oil was evaluated on population dynamics of a bacterial consortium (Acinetobacter baumannii LBBMA 04, Pseudomonas aeruginosa LBBMA 58, Ochrobactrum anthropi LBBMA 88b, Acinetobacter baumannii LBBMAES11, and Bacillus subtilis LBBMA 155) and on biodegradation of petroleum hydrocarbons (n-C12-C22). After each contamination with diesel oil, soil samples were collected for assessment of bacterial population and sequence of petroleum hydrocarbons degradation. At 20 and 40 days, the highest percentage of degradation was observed for the higher carbon chain hydrocarbons (n-C21 and C22). After the third contamination, there was a considerable reduction of n-C21degradation and a high degradation of hydrocarbons n-C13-15, C17 and C19, which contrasts with the low values of degradation of these hydrocarbons in the two previous phases. The highest growth rate of all members of the consortium occurred from 0 to 20 days, but population increase continued up to the end of the experiment (except for B. subitillis strain, whose population stabilized after 20 days). Our results show that the recurrent contamination by hydrocarbons affected the population structure of bacterial consortium and increased the total population density of the bacterial consortium.

O efeito da contaminação do solo com óleo diesel foi avaliado sobre a dinâmica populacional bacteriana de um consórcio (Acinetobacter baumannii LBBMA 04, Pseudomonas aeruginosa LBBMA 58, Ochrobactrum anthropi LBBMA 88b, Acinetobacter baumannii LBBMAES11 e Bacillus subtilis LBBMA 155) e sobre a biodegradação de hidrocarbonetos de petróleo (n-C12-C22). Após cada evento de contaminação com óleo diesel, foram coletadas amostras de solo para avaliação das populações bacterianas e da sequência de degradação de hidrocarbonetos de petróleo. Aos 20 e 40 dias, a maior porcentagem de degradação foi observada para os hidrocarbonetos de cadeia de carbono mais elevada (n-C21 e C22). Após a terceira contaminação, houve redução considerável da degradação de n-C21 e alta degradação dos hidrocarbonetos n-C13-15, C17 e C19, o que contrasta com os baixos valores de degradação desses hidrocarbonetos nas duas fases anteriores. A maior taxa de crescimento de todos os membros do consórcio ocorreu entre 0 e 20 dias, mas o aumento populacional continuou até o final do experimento (com exceção da linhagem B. subitilis, cuja população se estabilizou após 20 dias). Os resultados mostram que a contaminação sucessiva do solo com óleo diesel afetou a estrutura populacional do consórcio bacteriano e proporcionou aumento da densidade populacional total das bactérias.

Interaction of pesticides with natural and synthetic solids. Evaluation in dynamic and equilibrium conditions.

Interactions between pesticides (paraquat, glyphosate, 2,4-D, atrazine, and metsulfuron methyl) and soil organic and inorganic components have been studied in batch experiments by performing adsorption, dissolution, and chemical and photochemical degradation under different conditions. The obtained results confirm that the affinity of a pesticide to the solid surface depends on the nature of both and shows that each reactant strongly affects the mobility of the other one, e.g., anionic pesticides promote the dissolution of the solid humic acid but if this last is retained into the inorganic matrix enhances the adsorption of a cationic pesticide. Adsorption also seems to protect the bonded specie to be chemical degraded, such as shown in two pesticide/clay systems at constant pH. The use of mesoporous silicas could result in a good alternative for pesticide remediation. In fact, the solid shows high adsorption capacity towards paraquat and its modification with TiO2 nanoparticles increases not only the pesticide adsorption but also seems to catalyze its degradation under UV light to less-toxic metabolites. UV-VIS spectroscopy was relevant and novel in such sense. Electrostatic interactions, hydrogen and coordinative bonds formations, surface complexations and hydrophobic associations play a key role in the fate of mentioned pesticides on soil and ground/surface water environments.

Enrichment of population density of a bacterial consortium during bioremediation of a soil under successive contaminations with diesel oil / Enriquecimento da densidade populacional de um consórcio bacteriano durante a biorremediação de um solo sob sucessivas contaminações com óleo diesel

The effect of successive soil contamination with diesel oil was evaluated on population dynamics of a bacterial consortium (Acinetobacter baumannii LBBMA 04, Pseudomonas aeruginosa LBBMA 58, Ochrobactrum anthropi LBBMA 88b, Acinetobacter baumannii LBBMAES11, and Bacillus subtilis LBBMA 155) and on biodegradation of petroleum hydrocarbons (n-C12-C22). After each contamination with diesel oil, soil samples were collected for assessment of bacterial population and sequence of petroleum hydrocarbons degradation. At 20 and 40 days, the highest percentage of degradation was observed for the higher carbon chain hydrocarbons (n-C21 and C22). After the third contamination, there was a considerable reduction of n-C21degradation and a high degradation of hydrocarbons n-C13-15, C17 and C19, which contrasts with the low values of degradation of these hydrocarbons in the two previous phases. The highest growth rate of all members of the consortium occurred from 0 to 20 days, but population increase continued up to the end of the experiment (except for B. subitillis strain, whose population stabilized after 20 days). Our results show that the recurrent contamination by hydrocarbons affected the population structure of bacterial consortium and increased the total population density of the bacterial consortium.(AU)

O efeito da contaminação do solo com óleo diesel foi avaliado sobre a dinâmica populacional bacteriana de um consórcio (Acinetobacter baumannii LBBMA 04, Pseudomonas aeruginosa LBBMA 58, Ochrobactrum anthropi LBBMA 88b, Acinetobacter baumannii LBBMAES11 e Bacillus subtilis LBBMA 155) e sobre a biodegradação de hidrocarbonetos de petróleo (n-C12-C22). Após cada evento de contaminação com óleo diesel, foram coletadas amostras de solo para avaliação das populações bacterianas e da sequência de degradação de hidrocarbonetos de petróleo. Aos 20 e 40 dias, a maior porcentagem de degradação foi observada para os hidrocarbonetos de cadeia de carbono mais elevada (n-C21 e C22). Após a terceira contaminação, houve redução considerável da degradação de n-C21 e alta degradação dos hidrocarbonetos n-C13-15, C17 e C19, o que contrasta com os baixos valores de degradação desses hidrocarbonetos nas duas fases anteriores. A maior taxa de crescimento de todos os membros do consórcio ocorreu entre 0 e 20 dias, mas o aumento populacional continuou até o final do experimento (com exceção da linhagem B. subitilis, cuja população se estabilizou após 20 dias). Os resultados mostram que a contaminação sucessiva do solo com óleo diesel afetou a estrutura populacional do consórcio bacteriano e proporcionou aumento da densidade populacional total das bactérias.(AU)

O uso de estratégias focadas em resultados para o controle da poluição hídrica no Brasil / The use of goal-oriented strategies for water pollution control in Brazil

RESUMO O presente artigo objetivou apresentar uma visão geral sobre o emprego de estratégias focadas em resultados (EFR), tais como a de pagamento por resultados (PPR) e a de pagamento por serviços ambientais (PSA), na redução e no controle da poluição hídrica em áreas urbanas e rurais do país. Para isso, considerando-se sempre o objetivo da Gestão Integrada de Recursos Hídricos (GIRH), duas experiências de alcance nacional foram revisitadas: a do Programa Despoluição de Bacias Hidrográficas (Prodes) e a do Programa Produtor de Águas, ambos executados pela Agência Nacional de Águas (ANA), o primeiro iniciado há mais de uma década. Esses programas ilustram abordagens bem-sucedidas de aproximação do poder público com os setores usuários de água, nesse caso, os setores de saneamento e agricultura, respectivamente. Por fim, foram discutidas a aplicabilidade e as perspectivas para a implementação de novas iniciativas de EFR para GIRH no Brasil.

ABSTRACT This paper presents an overview about the use of goal-oriented strategies, such as output-based aid (OBA) and payment for environmental services (PES), for water pollution abatement and control in urban and rural areas throughout the country. Thus, considering the goal of implementing IWRM, two nation-wide experiences are reviewed: the River Basin Clean-Up Program (PRODES) and the Water Producer Program, both run by the National Water Agency (ANA), the former initiated over a decade ago. They illustrate successful ways to bring public authorities and water users together, in this case, sanitation services and landowners, respectively. Finally, it is discussed the applicability and perspectives for carrying out new goal-oriented initiatives aimed at IWRM in Brazil.

Assessment of methane biodegradation kinetics in two-phase partitioning bioreactors by pulse respirometry.

Biological methane biodegradation is a promising treatment alternative when the methane produced in waste management facilities cannot be used for energy generation. Two-phase partitioning bioreactors (TPPBs), provided with a non-aqueous phase (NAP) with high affinity for the target pollutant, are particularly suitable for the treatment of poorly water-soluble compounds such as methane. Nevertheless, little is known about the influence of the presence of the NAP on the resulting biodegradation kinetics in TPPBs. In this study, an experimental framework based on the in situ pulse respirometry technique was developed to assess the impact of NAP addition on the methane biodegradation kinetics using Methylosinus sporium as a model methane-degrading microorganism. A comprehensive mass transfer characterization was performed in order to avoid mass transfer limiting scenarios and ensure a correct kinetic parameter characterization. The presence of the NAP mediated significant changes in the apparent kinetic parameters of M. sporium during methane biodegradation, with variations of 60, 120, and 150% in the maximum oxygen uptake rate, half-saturation constant and maximum specific growth rate, respectively, compared with the intrinsic kinetic parameters retrieved from a control without NAP. These significant changes in the kinetic parameters mediated by the NAP must be considered for the design, operation and modeling of TPPBs devoted to air pollution control.

XRF analysis of sediments from Nuevitas Bay (Cuba): assessment of current heavy metal contamination / Análisis por FRX de sedimentos de la Bahía de Nuevitas (Cuba): evaluación de la contaminación actual por metales pesados

Concentrations of chromium, nickel, copper, zinc and lead in surface sediments from six stations located in Nuevitas Bay (Cuba) were estimated by X-ray fluorescence analysis. The Cr content in sediments shows a strong variation across the studied stations (89-513 ), in contrast with the other elements studied. The application of modified degree of contamination () classifies as moderate the contamination of Nuevitas Bay. The comparison with Sediment Quality Guidelines (SQGs) and toxicity mean quotients shows that 100 % of the sediments are associated with the occasional presence of possible adverse effects to human health.

Se determinan, mediante el análisis por fluorescencia de rayos X, las concentraciones de cromo, níquel, cobre, zinc y plomo en sedimentos superficiales de seis estaciones de la Bahía de Nuevitas en Cuba. El contenido de cromo se determinó con un intervalo de gran variación (89-513 ) en las estaciones estudiadas. La aplicación del grado de contaminación modificado () clasificó la contaminación de los sedimentos de la Bahía de Nuevitas como de “grado moderado”. La comparación con las Guías de Calidad de Sedimentos y del cociente promedio de toxicidad, mostró que el 100 % de los sedimentos estudiados están asociados a la presencia ocasional de posibles efectos adversos a la salud humana.

Analise de Modos e Efeitos de Falha na avaliacao dos impactos ambientais provenientes do abate animal / Failure Mode and Effect Analysis for the evaluation of environmental impacts of animal slaughter

A Análise de Modos e Efeitos de Falha (AMEF) é um método de análise de produto ou processo para detectar e eliminar problemas potenciais de forma sistemática e completa. Os abatedouros levam a significativos impactos sobre o meio ambiente, sendo que o maior problema nesses processos é a falta de equipamentos modernos para promover a remoção de gases fétidos e efluentes tóxicos. O objetivo deste trabalho foi elaborar os formulários de aplicação do FMEA em um frigorífico de médio porte da região de Poços de Caldas (MG), o qual realiza abates de bovinos e suínos, cujo intuito foi diagnosticar os potenciais riscos gerados pelo frigorífico, e aos controles ambientais exercidos em relação à linha de abate e graxaria. Observou-se que a indústria frigorífica representa um grande potencial poluidor sobre os efluentes naturais, pois o sangue resultante do abate é um agente de grande impacto sobre o ecossistema hídrico.

The Failure Mode and Effect Analysis (FMEA) is a method of product or process analysis to detect and eliminate potential problems in a systematic and complete way. The abattoirs lead to significant impacts on the environment, which the major problem in those processes is the lack of modern equipment to promote the removal of malodorous gases and toxic effluents. The aim of this study was to elaborate the FMEA application forms in a medium-sized abattoir in the region of Poços de Caldas (MG), which performs the cattle and pig slaughter, with the purpose of diagnosing its potential risks caused, and the environmental controls exercised in relation to the slaughter line and rendering plant. It was observed that the meat industry represents a great potential pollution on the natural effluents, because the resulting blood of the slaughter is an agent of great impact on the water ecosystem.

Niveles de radionúclidos naturales y metales pesados en suelos urbanos de la ciudad de Cienfuegos, Cuba / Heavy metal and natural radionuclide levels in urban soils from Cienfuegos city, Cuba

Se determinan las concentraciones de metales pesados y radionúclidos naturales en suelos superficiales (0-10 cm) de la ciudad de Cienfuegos, Cuba, mediante las técnicas de fluorescencia de rayos X y espectrometría gamma respectivamente. Los resultados de la medición de metales pesados mostraron que las concentraciones promedio de Ni, Cu, Zn y Pb en los suelos estudiados son superiores a los valores correspondientes de fondo. El cálculo del Índice de Polución Integral permitió determinar que estos suelos presentan una contaminación severa por metales pesados. Las concentraciones de , y en los suelos urbanos de Cienfuegos se encuentran en los intervalos de 8.3-32.7, 3.7-10.7 y 129-356 , con promedios de 22.6, 6.3 y 272 respectivamente, valores que son similares a los reportados para la zona Centro-Sur de Cuba. La tasa de dosis absorbida en aire y la dosis equivalente efectiva anual que recibe la población local producto de la radiación natural es inferior a los límites establecidos internacionalmente. Se determinaron correlaciones positivas significativas de -Cu y -Zn, indicando la posible presencia de una fuente de contaminación por estos elementos en la zona.

Concentrations of heavy metals and natural radionuclides in topsoil (0-10cm) from Cienfuegos city, Cuba, were determined by using X-ray fluorescence analysis and gamma ray spectrometry, respectively. The measured results of heavy metals show that the mean concentrations of Ni, Cu, Zn and Pb in the studied soil samples are higher than their corresponding background values. The calculated results of integrated pollution index of heavy metals indicate that the studied soils present severely heavy metal contamination. The concentrations of , and in the studied soil samples range from 8.3 to 32.7, 3.7 to 10.7 and 129 to 356 with an average of 22.6, 6.3 and 272 , respectively, which are similar than the average concentrations reported for South-central Cuban soils. The air absorbed dose rate and the annual effective dose equivalent received by the local residents due to the natural radionuclides in soil are lesser than the worldwide established limits. A significantly positive -Cu and -Zn correlations were determined, indicating the possible existence of a source of pollution due to the presence of these elements in the area.

Characterization of an acidification and equalization tank (AET) operating as a primary treatment of swine liquid effluent

This work evaluated the potential of the acidification equalization tank (AET) used as a primary treatment unit, treating the hog farming wastewater. The treatment system consisted of a degritter with a triangular-notch weir, for measuring the flow, a static sieve, and an acidification and equalization tank (AET), an anaerobic baffled reactor (ABR), an upflow anaerobic sludge blanket (UASB) reactor, a settling tank, a greenhouse for fertirrigation and two infiltration ponds. The AET had a net capacity of 8,000 liters, internally covered with asphalt blanket, worked based on surface loading rates application. The unit operated continuously, with its flow varying from 0.1 to 10 L s-1. To determine the efficiency, the following parameters were measured: pH; COD; BOD; volatile and fixed solids; settleable solids; total, intermediate and partial alkalinity and total acidity. The COD removal varied from 5 to 20%. The average pH was 7.3 and the total, intermediate and partial alkalinity in the effluent, were 1919, 846, 1197 mg L-1, respectively. The total acidity in the effluent was 34 mg L-1. The influent and effluent total BOD and oil & grease concentrations were 3436 and 3443 mg L-1, and 415 and 668 mg L-1, respectively. It was found that the AET worked properly concerning the acidification, equalization and sedimentation processes, confirming low cost of implementation and easy operation, when compared to other traditional decanters.