Using causal maps to support ex-post assessment of social impacts of dams

This paper presents the results of an ex-post assessment of two important dams in Brazil. The study follows the principles of Social Impact Management, which offer a suitable framework for analyzing the complex social transformations triggered by hydroelectric dams. In the implementation of this approach, participative causal maps were used to identify the ex-post social impacts of the Porto Primavera and Rosana dams on the community of Porto Rico, located along the High Paraná River. We found that in the operation of dams there are intermediate causes of a political nature, stemming from decisions based on values and interests not determined by neutral, exclusively technical reasons; and this insight opens up an area of action for managing the negative impacts of dams.

Large scale optimization of a sour water stripping plant using surrogate models

In this work, we propose a new methodology for the large scale optimization and process integration of complex chemical processes that have been simulated using modular chemical process simulators. Units with significant numerical noise or large CPU times are substituted by surrogate models based on Kriging interpolation. Using a degree of freedom analysis, some of those units can be aggregated into a single unit to reduce the complexity of the resulting model. As a result, we solve a hybrid simulation-optimization model formed by units in the original flowsheet, Kriging models, and explicit equations. We present a case study of the optimization of a sour water stripping plant in which we simultaneously consider economics, heat integration and environmental impact using the ReCiPe indicator, which incorporates the recent advances made in Life Cycle Assessment (LCA). The optimization strategy guarantees the convergence to a local optimum inside the tolerance of the numerical noise.

Projeto – sustentabilidade e matemática

A disciplina matemática e o tema sustentabilidade podem ser muito bem trabalhados pelos docentes da área de exatas. Pois, saber quantificar, calcular e associar o consumo e o impacto ambiental através de dados numéricos é uma possibilidade que pode ser desenvolvida em sala de aula. Saber interpretar e construir gráficos de colunas são outras competências e habilidades presentes na ciência da matemática. Compreender conceitos, estratégias e situações matemáticas numéricas para aplicá-los a situações diversas no contexto das ciências, da tecnologia e da atividade cotidiana se faz necessário. E também, reconhecer, pela leitura de textos apropriados, a importância da Matemática na elaboração de proposta de intervenção solidária na realidade. Dessa forma, conhecer o ambiente em que vivemos, verificar a influência do homem na Natureza e quais ações deverão ser tomadas pensando nas futuras gerações é um despertar para o consumo consciente. O que acarreta como possibilidade o retorno à natureza de recursos utilizados de maneira correta. Conhecer uma conta de luz detalhada, aprender a calcular o consumo mensal de Kwh e diminuir o consumo de energia elétrica através da mudança de hábitos são exemplos cotidianos em que a matemática se faz presente. Relacionar a matemática ao estudo do meio ambiente proporciona através dos números mensurar os prejuízos e projetar soluções, torna a aprendizagem construtiva, podendo se constituir num comportamento cotidiano ou numa ação educativa para formar uma consciência ecológica dentro de indicadores reais. A aprendizagem se torna significativa quando relacionada ao cotidiano do aluno no sentido de mostrar o meio ambiente a que estão inseridos para que possam ser agentes transformadores, através da mudança de hábitos e principalmente desenvolvendo suas habilidades matemáticas. Sendo assim, o processo de ensino aprendizagem matemática-meio ambiente é realizado no sentido de oportunizar o conhecimento do mundo e domínio da natureza, com base nas linguagens matemáticas, criando-se condições de melhorar a capacidade de agir na sociedade, assumindo ações permanentes concentradas em um desenvolvimento sustentável para a continuidade da vida na Terra. Nesse diapasão, é possível desenvolver trabalhos pedagógicos “na trilha da matemática: do raciocínio ao meio-ambiente”. A resolução de situações problemas e assuntos referentes ao meio ambiente fazem com que os alunos tomem os cuidados necessários para com o meio ambiente, aos recursos por ele oferecidos e as consequências das ações errôneas causadas pelo homem.

Bioindicators as metrics for environmental monitoring of desalination plant discharges

Development of desalination projects requires simple methodologies and tools for cost-effective and environmentally-sensitive management. Sentinel taxa and biotic indices are easily interpreted in the perspective of environment management. Echinoderms are potential sentinel taxon to gauge the impact produced by brine discharge and the BOPA index is considered an effective tool for monitoring different types of impact. Salinity increase due to desalination brine discharge was evaluated in terms of these two indicators. They reflected the environmental impact and recovery after implementation of a mitigation measure. Echinoderms disappeared at the station closest to the discharge during the years with highest salinity and then recovered their abundance after installation of a diffuser reduced the salinity increase. In the same period, BOPA responded due to the decrease in sensitive amphipods and the increase in tolerant polychaete families when salinities rose. Although salinity changes explained most of the observed variability in both indicators, other abiotic parameters were also significant in explaining this variability.

Investigation of Performance Enhancements for a Liquid-Desiccant Solar Air-Conditioner

Thermally driven liquid-desiccant air-conditioners (LDAC) are a proven but still developing technology. LDACs can use a solar thermal system to reduce the operational cost and environmental impact of the system by reducing the amount of fuel (e.g. natural gas, propane, etc.) used to drive the system. LDACs also have a key benefit of being able to store energy in the form of concentrated desiccant storage. TRNSYS simulations were used to evaluate several different methods of improving the thermal and electrical coefficients of performance (COPt and COPe) and the solar fraction (SF) of a LDAC. The study analyzed a typical June to August cooling season in Toronto, Ontario. Utilizing properly sized, high-efficiency pumps increased the COPe to 3.67, an improvement of 55%. A new design, featuring a heat recovery ventilator on the scavenging-airstream and an energy recovery ventilator on the process-airstream, increased the COPt to 0.58, an improvement of 32%. This also improved the SF slightly to 54%, an increase of 8%. A new TRNSYS TYPE was created to model a stratified desiccant storage tank. Different volumes of desiccant were tested with a range of solar array system sizes. The largest storage tank coupled with the largest solar thermal array showed improvements of 64% in SF, increasing the value to 82%. The COPe was also improved by 17% and the COPt by 9%. When combining the heat recovery systems and the desiccant storage systems, the simulation results showed a 78% increase in COPe and 30% increase in COPt. A 77% improvement in SF and a 17% increase in total cooling rate were also predicted by the simulation. The total thermal energy consumed was 10% lower and the electrical consumption was 34% lower. The amount of non-renewable energy needed from the natural gas boiler was 77% lower. Comparisons were also made between LDACs and vapour-compression (VC) systems. Dependent on set-up, LDACs provided higher latent cooling rates and reduced electrical power consumption. Negatively, a thermal input was required for the LDAC systems but not for the VC systems.

Landfill Leachate Toxicity to Oncorhynchus mykiss (Rainbow Trout) at the Merrick Landfill

At the Merrick Landfill, located outside of North Bay (Ontario, CA), an investigation into the potential for an environmental impact to the Little Sturgeon River as a result of landfill leachate discharge was undertaken using toxicity testing using 96 hour acute lethality on Oncorhynchus mykiss (Rainbow Trout). Landfill leachate may present a risk to receiving environments as it is comprised of an array of chemicals including organics, ammonia, and metals. Testing was conducted in three phases, firstly testing was completed on site throughout an existing natural attenuation zone where the presence of several groundwater seeps down gradient of the site had been identified to determine the effectiveness of the existing leachate control features at reducing the environmental risks. These tests indicated that the existing capture strategies were largely effective at reducing toxicity risks to the receiving environment. Testing was also completed on two pilot-scale hybrid-passive treatment systems to determine their effectiveness for leachate treatment. Summer performance of a constructed gravel wetland system was also shown to be effective at reducing the toxicity of the landfill leachate at the site. Lastly in order to support evaluation of leachate treatment requirements, a toxicity identification evaluation (TIE) was performed to determine the principle cause of toxicity within the leachate. Based on water chemistry analyses of samples collected at various locations at the site, the TIE identified ammonia toxicity as the primary source of toxicity in the leachate, with a secondary focus on metal toxicity.

Analyse du métabolisme du soufre de la bactérie autotrophique acidophile Acidithiobacillus thiooxidans ATCC 19377

Les impacts environnementaux dues à l'extraction minière sont considérables. C'est l'action des microorganismes, en utilisant leur métabolisme du soufre sur les déchets miniers, qui engendre les plus grands défis. Jusqu'à présent, peu de recherches ont été effectués sur les microorganismes environnementaux pour la compréhension globale de l'action du métabolisme du soufre dans une optique de prévention et de rémédiation des impacts environnementaux de l'extraction minière. Dans cette étude, nous avons étudié une bactérie environnementale, Acidithiobacillus thiooxidans, dans le but de comprendre le métabolisme du soufre selon le milieu de culture et le niveau d'acidité du milieu. Nous avons utilisé la transcriptomique à haut débit, RNA-seq, en association avec des techniques de biogéochimie et de microscopie à électrons pour déterminer l'expression des gènes codants les enzymes du métabolisme du soufre. Nous avons trouvé que l'expression des gènes des enzymes du métabolisme du soufre chez ce microorganisme sont dépendantes du milieu, de la phase de croissance et du niveau d'acidité présent dans le milieu. De plus, les analyses biogéochimiques montrent la présence de composés de soufre réduits et d'acide sulfurique dans le milieu. Finalement, une analyse par microscopie électronique révèle que la bactérie emmagasine des réserves de soufre dans son cytoplasme. Ces résultats permettent une meilleure compréhension de son métabolisme et nous rapprochent de la possibilité de développer une technique de prédiction des réactions ayant le potentiel de causer des impacts environnementaux dus à l'extraction minière.

The Impact of Banking Structural Reform on Household Retail Finance. ECRI Commentary No. 13, 7 October 2014

There are two main objectives behind the EC proposal on banking structural reform: the financial stability objective and the economic efficiency objective. If it is implemented, the reform should reinforce the stability and economic efficiency of household retail activities through lower contagion, better resolvability in the event of failure, more harmonised supervisory practices across the EU and more resilient household demand for retail loans. However, it could also trigger counterproductive effects that could partly undermine the expected benefits. These potential negative effects are not appropriately assessed in the impact study of the proposal published in January 2014 and will require further consideration in the coming months. In particular, the stability of household retail finance could be strengthened by placing more emphasis on bankruptcy risks of retail banks; the transfer of existing systemic activities towards less regulated and supervised markets and reputational risk. A better analysis of the borrowing costs for households (impacted by the potential decreasing diversification of the funding base of banks and scarcer liquidity) and implementation costs could help regulators to achieve the objective of efficient household activities.

Benthic fauna of an offshore borrow area in Broward County, Florida /

Benthic fauna from two stations within a 5-year-old borrow area and two control stations off Hillsboro Beach (Broward County), Florida, were sampled quarterly from June 1977 to March 1978 to evaluate the long-term impact of offshore dredging. Generally enhanced productivities occurred within the borrow area, although there was much seasonal variation among stations. Species diversities were usually higher at the borrow stations than at the control stations. The single exception was due to a high concentration of the bivalve E. nitens at one of the control stations in June. Although faunal similarity analysis revealed a qualitative change in the fauna of the borrow area, this change is not considered detrimental. Conspicuous patterns of heterogeneous faunal distributions were evident in this study, particularly for the bivalve E. nitens. No lasting detrimental effects, in terms of numbers of species, faunal densities, or species diversity, resulted from the dredging operation. (Author).

Long-term changes in beach fauna at Duck, North Carolina /

Long-term changes in the beach fauna at Duck, North Carolina, were investigated. Twenty-one stations located on three transects on the oceanside and twenty-four stations located on three transects on the sound side were sampled seasonally from November 1980 to July 1981. The data collected in this study were compared to a previous study conducted in 1976 (Matta, 1977) to investigate the potential effects of the construction of the CERC Field Research Facility pier on the adjacent beaches. No effects on the benthic fauna were found. Changes observed in the benthic macrofauna on the ocean beaches were well within the range attributable to the natural variation of an open coast system. The ocean beach macrofauna was observed to form a single community migrating on an off the beach with the seasons. On the sound beaches, changes were detected in the benthic macrofauna; however, these were attributed to a salinity increase during the 1981 sampling year. (Author).

Effects of beach nourishment on the nearshore environment in Lake Huron at Lexington Harbor (Michigan) /

In October 1980 the U.S. Army Corps of Engineers conducted a beach nourishment project at the Lexington (Michigan) Harbor on the southwest shore of Lake Huron, a project designed to mitigate beach erosion attributable to the installation of the harbor. In response to a request from the Coastal Engineering Research Center (CERC), the U.S. Fish and Wildlife Service's Great Lakes Fishery Laboratory conducted a Corps-funded study from June 1980 to October 1981 along a 8.4-kilometer segment of shoreline adjacent to the harbor to determine the effect of the Corps' beach nourishment project on the nearshore aquatic environment. The study performed by the service included aerial photographic surveys of the study area; measurement of dissolved oxygen, turbidity, and suspended particulate matter levels; and collection of lake bottom sediments, macrozoobenthos and fish. Analysis of the aerial photographs showed that the beach face profile changed markedly during the study as a result of beach nourishment. Dredging of about 19,000 cubic meters of beach sediment from an accretion area adjacent to the harbor's north breakwater caused the beach face to recede, while deposition of this sediment on a feeder beach south of the harbor caused the beach face there to extend lakeward.

The energy and environmental consequences of increased vehicle size and weight - volume I - final report.

Transportation Department, Research and Special Programs Administration, Washington, D.C.

Sourcebook on transit-related environmental regulations: requirements affecting the acquisition and maintenance of transit vehicles and facilities. Final report.

Federal Transit Administration, Washington, D.C.

Economic impact of highway snow and ice control. Final report.

Federal Highway Administration, Washington, D.C.

Economic impact of highway snow and ice control. ESIC - user's manual.

Federal Highway Administration, Washington, D.C.