Relationships between fecal indicators and pathogenic microorganisms in a tropical lagoon in Rio de Janeiro, Brazil

Rodrigo de Freitas Lagoon is an urban ecosystem undergoing accelerated degradation, therefore selected as a model for microbiological quality studies of tropical lagoons. The aim of this study was to evaluate the abundance and the spatial distribution of fecal pollution indicators and pathogenic microorganisms in the lagoon. The relationships between microbial groups and abiotic measurements were also determined to evaluate the influence of environmental conditions on bacterial distribution and to identify the capability of coliforms and Enterococcus to predict the occurrence of Vibrio, Staphylococcus aureus, and Salmonella. Surface water samples were collected monthly, from December 1999 to October 2000. Analyses were performed by traditional culture techniques. A uniform spatial distribution was observed for all bacterial groups. The fecal pollution indicators occurred in low abundances while potentially pathogenic microorganisms were consistently found. Therefore, our study supported the use of counts of coliforms and Enterococcus to indicate only recent fecal contamination.     

Microplastics as vectors of metals contamination in Mediterranean Sea

Environmental Science and Pollution Research - Microplastics are contaminants of great concern all over the world. Microplastics constitute pollutants themselves; moreover, other contaminants such...     

Antibiotic-resistant Pseudomonas aeruginosa from hospital wastewater and superficial water: Are they genetically related?

Many studies have reported the presence of antibiotic-resistant Pseudomonas aeruginosa in environmental samples such as hospital wastewater and surface water. The present study evaluated the contribution of untreated hospital wastewater to the dissemination of resistant P. aeruginosa strains in aquatic environments, through the analysis of their antibiotic susceptibility profile and genetic similarity. Wastewater samples were collected from two hospitals located in Rio Grande do Sul, RS, Brazil. Superficial water samples were collected from water bodies that received this wastewater discharge. The antibiotic susceptibility profiles of the strains were determined using the disk-diffusion technique and their genotyping was done by amplification of the Enterobacterial Repetitive Intergenic Consensus sequences (ERIC-PCR). The antibiotic resistance was higher among the hospital wastewater strains and the multiresistant phenotype was also observed only among these strains. The ERIC-PCR profiles did not reveal any genetic similarity among the P. aeruginosa strains from the wastewater and superficial water samples. On the contrary, they showed that genetically distinct populations were established in these different environments and probably that some other contamination source could be contributing to the presence of resistant strains in these water bodies.     

Multi-criteria analysis for improving strategic environmental assessment of water programmes. A case study in semi-arid region of Brazil

Multi-criteria analysis (MCA) is a family of decision-making tools that can be used in strategic environmental assessment (SEA) procedures to ensure that environmental, social and economic aspects are integrated into the design of human development strategies and planning, in order to increase the contribution of the environment and natural resources to poverty reduction. The aim of this paper is to highlight the contribution of a particular multi-criteria technique, the analytic hierarchy process (AHP), in two stages of the SEA procedure applied to water programmes in developing countries: the comparison of alternatives and monitoring. This proposal was validated through its application to a case study in Brazilian semi-arid region. The objective was to select and subsequently monitor the most appropriate programme for safe water availability. On the basis of the SEA results, a project was identified and implemented with successful results. In terms of comparisons of alternatives, AHP meets the requirements of human development programme assessment, including the importance of simplicity, a multidisciplinary and flexible approach, and a focus on the beneficiaries' concerns. With respect to monitoring, the study shows that AHP contributes to SEA by identifying the most appropriate indicators, in order to control the impacts of a project.     

Trace elements fingerprint of feathers differs between breeding and non-breeding areas in an Afro-Palearctic migratory bird,the barn swallow (Hirundo rustica)

Environmental Science and Pollution Research - Trace elements are widespread contaminants that can potentially threaten ecosystems and human health. Considering their distribution and toxicity,...     

Eco-industrial park development in Rio de Janeiro,Brazil: a tool for sustainable development

The development of eco-industrial parks (EIPs) is an emerging concept that is being spread worldwide as a new industrial model that can reconcile the three dimensions of sustainability: social, economic and environmental. In Rio de Janeiro, Brazil, EIPs were launched through formal legislation as a means to foster sustainable development and to ameliorate the distress caused by unplanned urban and industrial development. The objective of this study is to present and analyze the development of EIPs in Rio de Janeiro, focusing on two of the initiatives launched. We argue that Rio de Janeiro has the potential for developing a sustainable industrial system through EIP implementation, but the continuity of EIPs will only be successful if there is convergence of interests among the actors involved.     

Press-extrusion pretreatment of the organic fraction of municipal solid waste for enhanced methane production

Anaerobic digestion (AD) is a well-established process for the treatment of a wide variety of solid organic substrates, including the organic fraction of municipal solid waste (OFMSW). At industrial scale, the mechanical pretreatment is a fundamental step to reduce OFMSW particle size and to promote the hydrolysis within the subsequent AD process. Among the mechanical pretreatment technologies, press-extrusion has recently raised great interest for its possible application to either enhance the organic load to the digester or improve the overall process stability and methane yields. Aim of this study was in assessing the potential of the press-extrusion pretreatment to improve the performance of OFMSW anaerobic degradation. Batch tests were set up according to a full factorial design of experiments to assess the significance of the main operating parameters. The statistical analysis of results addressed further tests, carried out under semi-continuous feeding mode, to better discuss the possible application of press-extrusion for the greatest valorization of OFMSW under anaerobic conditions.

     

Impacts of past and future land changes on landslides in southern Italy

Regional Environmental Change - Land use and land cover (LULC), as well as their geographical and temporal variations, affect landslide occurrence and the related risk, in ways that are difficult...     

Ranked set sampling allocation models for multiple skewed variables: an application to agricultural data

The mean of a balanced ranked set sample is more efficient than the mean of a simple random sample of equal size and the precision of ranked set sampling may be increased by using an unbalanced allocation when the population distribution is highly skewed. The aim of this paper is to show the practical benefits of the unequal allocation in estimating simultaneously the means of more skewed variables through real data. In particular, the allocation rule suggested in the literature for a single skewed distribution may be easily applied when more than one skewed variable are of interest and an auxiliary variable correlated with them is available. This method can lead to substantial gains in precision for all the study variables with respect to the simple random sampling, and to the balanced ranked set sampling too.     

Phytoplankton photosynthetic activity and growth rates in the NW Adriatic Sea

Taxonomic composition, biomass, primary production and growth rates of the phytoplankton community were studied in two stations in the NW Adriatic Sea on a seasonal basis, in areas characterized by differing hydrological and trophic conditions. The main differences between the two stations were quantitative rather than qualitative, most phytoplankton species being common to both stations. The effects of differing nutrient concentrations and plume spreading were evident. Biomass and primary production rates were significantly higher in the coastal station (S1), and the phytoplankton distribution in the water column was markedly stratified in S1 and more even in the offshore station (S3). However, chlorophyll a specific production, potential growth rate and production efficiencies were very similar in both stations, even when phosphorus concentrations were limiting. A discrepancy between potential and actual growth rate was observed: as a feature common to both stations, comparisons between potential and actual growth rates revealed that little carbon produced by phytoplankton accumulated as algal biomass; therefore, very high loss rates were estimated.