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Ecological risk assessment of a tropical metal contaminated area: the case study of Santo Amaro, Bahia, Brazil

Niemeyer, Júlia Carina
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
15.89%
O presente estudo, realizado na área abandonada de uma fundição de chumbo no Brasil, teve como principal objetivo contribuir para a aplicação, em ambientes tropicais, de um esquema de análise de risco ecológico em etapas, e avaliar a adequabilidade dos diferentes parâmetros nas etapas dentro do enfoque da Tríade. Buscou-se caracterizar o risco ecológico em vários pontos da área de estudo, uma das mais contaminadas por metais do mundo, em Santo Amaro (BA, Brasil), fornecendo informações que indiquem possíveis medidas de remediação para o local e trazendo uma importante contribuição para decisões futuras. O objetivo deste trabalho é contribuir para o uso da avaliação de risco ecológico em processos de restauração e recuperação de locais contaminados no Brasil, seguindo as atuais tendências mundiais de proteção do solo. O Capítulo 2 apresenta a investigação preliminar, incluindo a fase de formulação do problema e o levantamento de informações científicas disponíveis sobre a área de estudo, resultando na elaboração de um modelo conceitual para o local e um plano de análise para a avaliação de risco. Um esquema em fases é proposto, integrando informações de três linhas de evidência (LoE): química...

Isolamento e seleção de microrganismos para remediação de efluente oleoso da indústria metal-mecânica; Isolation and selection of microorganisms for the oily effluent remediation of the metalworking industry

Queissada, Daniel Delgado
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/09/2009 PT
Relevância na Pesquisa
26.08%
A indústria metal-mecânica é responsável pela síntese de um dos efluentes oleosos mais complexos e difíceis de tratamento e reuso. Esses efluentes são constituídos, entre outros poluentes, por fluidos de corte, que servem para refrigerar e lubrificar peças metálicas no sistema de usinagem. Quando esses efluentes são tratados biologicamente é importante que se faça isso com microrganismos autóctones do mesmo, pois o uso desses microrganismos (bioaumentação) tende a ser mais eficaz, uma vez que os mesmos já estão adaptados aos poluentes nele existentes. Com este propósito, o presente trabalho teve como objetivo principal o isolamento e seleção de microrganismos para remediação de um efluente metalmecânico através de tratamentos unitários em bioreator do tipo air-lift e por sistema oxidativo UV/H2O2, além do tratamento integrado com ambos os processos. No tratamento biológico foram utilizados os microrganismos autóctones do efluente estudado, além do uso do fungo Aspergillus niger como microrganismo de referência. A caracterização do efluente bruto mostrou que, em decorrência dos parâmetros determinados como, 1495 mg Pt/L de cor, DQO de 9147 mg/L, 53 mg/L de fenóis-totais, 15666 mg/L de ST, 2,5 mgO2/L de OD...

Análise da evolução das transformações no rio Pinheiros e das políticas ambientais associadas, São Paulo - SP; Analysis of transformations of the Pinheiros River and the associated environmental policies, São Paulo - SP

Rodrigues, Fernanda Marques Guimarães
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/09/2012 PT
Relevância na Pesquisa
25.84%
Grandes aglomerações urbanas estão geralmente ligadas a seus corpos hídricos de abastecimento de água. Com a Região Metropolitana de São Paulo não foi diferente. Os rios Tietê e Pinheiros passaram por transformações no decorrer dos anos, interferindo no índice de qualidade de águas da Bacia do Alto Tietê. Há, ao mesmo tempo, um elevado consumo de água e inúmeras fontes poluidoras na forma de esgotos domésticos e efluentes industriais. A análise feita do Rio Pinheiros focou duas variáveis: as transformações gradativas e impactantes ocorridas no sistema e as políticas públicas, buscando identificar a relação de decorrência entre elas. As transformações foram analisadas pelos indicadores alterações ocorridas na paisagem e território do sistema, como a retificação e canalização do rio e seu uso e ocupação do solo. A partir de então, este contexto foi confrontado com as políticas públicas ambientais, focando no Projeto Tietê como principal indicador da variável política pública além da UGRH e da qualidade das águas para análise das mudanças ocorridas no sistema. Assim, esta pesquisa pode contribuir com a discussão da melhoria do uso dos recursos naturais metropolitanos. A pesquisa orienta-se pela perspectiva sistêmica apoiada nos conceitos de impactos e de derivações antropogenéticas dos sistemas...

Áreas alagadiças (Wetlands) para o tratamento de aqüíferos livres e rasos contaminados por nutrientes; Not available.

Santos, Jeane Gláucia
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/04/2002 PT
Relevância na Pesquisa
15.83%
A contaminação de aqüíferos rasos e livres por fossas sépticas e negras é um problema bastante sério, principalmente em países em desenvolvimento. Nesta dissertação pretendeu-se estudar processos de remediação de aqüíferos rasos e livres utilizando-se da técnica de wetlands, que são definidos como habitats onde o nível d'água pode estar na superfície, sobre, ou bem próximo a ela. Como exemplo destas áreas pode-se citar os pântanos, brejos e manguezais, mas há também os criados artificialmente, geralmente com fins ambientais. Através de modelagem matemática foram criados possíveis cenários da aplicação de wetlands artificiais para a atenuação de plumas contaminantes em aqüíferos rasos. A remediação dos aqüíferos apresenta, por meios desses processos estudados, baixo custo operacional. Os resultados obtidos indicam a necessidade de uma área superior 2.000 m² para a implantação de um sistema capaz de tratar 10 m³ de água por dia, considerando um tempo de residência de 10 a 15 dias. Este volume corresponde ao efluente produzido por 70 pessoas (150 L/hab/dia). O volume drenado e o tempo de permanência da água dentro do canal são inversamente proporcionais e fortemente controlados pela condutividade hidráulica do terreno...

Atributos físicos do solo, produção de biomassa e balanço energético em sistema de integração lavoura-pecuária leiteira sob plantio direto; Soil physical attributes, production of biomass and energy balance in system integration crop livestock dairy in tillage

Alba, Diane
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
25.75%
Os sistemas de integração lavoura-pecuária (ILP) permitem uma série de vantagens, porém a utilização intensiva do solo sem critérios técnicos quanto à pressão de pastejo e ao tráfego de máquinas, podem trazer prejuízos à qualidade física do solo, manifestada através da compactação. Nestes sistemas mais intensivos de produção há uma preocupação crescente em relação ao balanço energético. A grande quantidade de insumos adicionados à lavoura, nem sempre relacionados com aumento da produção, tem tornado os sistemas menos competitivos. Os objetivos do estudo foram avaliar os efeitos do pisoteio animal, somados ao tráfego de máquinas durante as operações agrícolas sobre os atributos físicos e rendimento das culturas; da escarificação como prática remediadora da compactação do solo na integração lavoura-pecuária leiteira; da introdução de leguminosa sobre o rendimento do milho; da aplicação de calcário no sistema ILP sobre a produção de culturas, bem como o balanço energético dos sistemas de produção. O experimento foi conduzido no município de Anta Gorda, situado no Vale do Taquari, sobre Neossolo Regolítico, no período de maio de 2010 a outubro de 2011. Os tratamentos principais constaram de duas culturas de cobertura de inverno (aveia preta com e sem pastejo e ervilhaca sem pastejo) e milho para silagem no período de verão...

Fotocatalise de percolado de aterro sanitario tratado por filtração lenta; Sanitary landfill leachate photocatalysis treated by low sand filter

Nubia Natalia de Brito Pelegrini
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 06/10/2008 PT
Relevância na Pesquisa
15.83%
Atualmente, uma das maiores preocupações ambientais está relacionada à grande geração de resíduos sólidos urbano. A disposição final em aterros sanitários é ainda uma prática que traz sérios impactos ao meio ambiente. Os resíduos em decomposição geram uma fração líquida conhecida como percolado de aterro sanitário, que é um líquido escuro com elevado potencial poluente. Os métodos convencionais de tratamento, comumente empregados em esgotos, têm demonstrado ineficiência na remediação do percolado que tem sido descartado nos corpos receptores com intensa coloração, elevadas concentrações de matéria orgânica, metais tóxicos e apresentando ainda alta toxicidade. Este trabalho teve como objetivo estudar um sistema integrado para o tratamento do percolado proveniente do aterro sanitário da cidade de Limeira-SP. O sistema consistiu em um tratamento preliminar por processo de filtração lenta e seqüencial tratamento por processos oxidativos avançados, sendo que, as técnicas fotocatálise heterogênea com TiO2/UV e fotocatálise homogênea com H2O2/UV foram experimentadas no processo de remediação. O filtro lento foi constituído por um tanque cilíndrico de polipropileno tendo como meio filtrante areia e mantas sintéticas não tecidas. A taxa de filtração adotada durante os experimentos foi de 3 m3/m2.dia. Os tratamentos fotocatalíticos foram realizados em um reator de vidro Pyrex com capacidade volumétrica de 1...

The use of Daphnia magna immobilization tests and soil microcosms to evaluate the toxicity of dredged sediments

Miranda, AFP; Rodrigues, JML; Barata, C; Riva, C; Nugegoda, D; Soares, AMVM
Fonte: Springer Verlag Publicador: Springer Verlag
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
15.83%
This paper evaluates the feasibility of using the buffering capacity of natural soil for the remediation of dredged material before being disposed in soil landfills. To achieve that, an Integrated Soil Microcosms (ISM) system was designed to produce elutriates and leachates from the sediment/soil percentage mixtures. Furthermore, to investigate the biological effects of the contaminated sediments, the toxicity behavior of leachates and elutriates was assessed and compared by performing acute (48 h) toxicity assays with the cladoceran Daphnia magna as test organism. Sediment samples contaminated with industrial residues were collected in November-December 2007 in a river area under the influence of the effluents from a chlor-alkali industry (Ebro River basin in Flix Reservoir, NE Spain). Uncontaminated natural soil was collected from a pesticide-free field. Particle size, pH, conductivity, total organic carbon, organic matter content, and soil and sediment moisture were determined. Eighty ISM were set up in the laboratory. To each ISM, 3 kg of fresh soil was added to form a 20-cm deep layer. Sediment and soil were mixed in the following proportions: 0:100, 10:90, 20:80, 35:65, and 50:50 (percent sediment/soil). Five hundred grams of the mixtures were placed at the top of each microcosm to form a 10-cm deep layer. The Integrated Soil Microcosm experiment ran for 60 days. Elutriates were obtained at days 1...

Evaluation of surface water quality using an ecotoxicological approach: a case study of the Alqueva Reservoir (Portugal)

Palma, P; Alvarenga, P; Palma, V; Matos, C; Fernandes, RM; Soares, AMVM; Barbosa, IR
Fonte: Springer Verlag Publicador: Springer Verlag
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
15.89%
Freshwater reservoirs can be impacted by several hazardous substances through inputs from agricultural activity, sewage discharges, and groundwater leaching and runoff. The water quality assessment is very important for implementation of the monitoring and remediation programs to minimize the risk promoted by hazardous substances in aquatic ecosystems. Evaluation of the degree of contamination of aquatic environments must not take in account only its chemical characterization but it must be complemented with biological assays, which determine potential toxic effects and allows an integrated evaluation of its effects in populations and aquatic ecosystem communities. The application of this type of strategy has clear advantages allowing a general evaluation of the effects from all the water components, including those due to unknown substances and synergic, antagonistic, or additive effects. There are only a few studies that reported ecotoxicological acute end points, for the assessment of surface water quality, and the relationship among toxicity results and the anthropogenic pollution sources and the seasonal period. The aim of this study was to assess the ecotoxicological characterization of the surface water from Alqueva reservoir (South of Portugal) and to evaluate the influence of anthropogenic sources of pollution and their seasonal variation in its toxicity. The construction of Alqueva reservoir was recently finished (2002) and...

The Impact of In-situ Chemical Oxidation on Contaminant Mass Discharge: Linking Source-Zone and Plume-Scale Characterizations of Remediation Performance

Brusseau, M.L.; Carroll, K.C.; Allen, T.; Baker, J.; DiGuiseppi, W.; Hatton, J.; Morrison, C.; Russo, A.; Berkompas, J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.1%
A large-scale permanganate-based in-situ chemical oxidation (ISCO) effort has been conducted over the past ten years at a federal Superfund site in Tucson, AZ, for which trichloroethene (TCE) is the primary contaminant of concern. Remediation performance was assessed by examining the impact of treatment on contaminant mass discharge, an approach that has been used for only a very few prior ISCO projects. Contaminant mass discharge tests were conducted before and after permanganate injection to measure the impact at the source-zone scale. The results indicate that ISCO caused a significant reduction in mass discharge (approximately 75%). The standard approach of characterizing discharge at the source-zone scale was supplemented with additional characterization at the plume scale, which was evaluated by examining the change in contaminant mass discharge associated with the pump-and-treat system. The integrated contaminant mass discharge decreased by approximately 70%, consistent with the source-zone-scale measurements. The integrated mass discharge rebounded from 0.1 to 0.2 Kg/d within one year after cessation of permanganate injections, after which it has been stable for several years. Collection of the integrated contaminant mass discharge data throughout the ISCO treatment period provided a high-resolution...

Electrochemically induced dual reactive barriers for transformation of TCE and mixture of contaminants in groundwater

Mao, Xuhui; Yuan, Songhu; Fallahpour, Noushin; Ciblak, Ali; Howard, Joniqua; Padilla, Ingrid; Loch-Caruso, Rita; Alshawabkeh, Akram N.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
15.84%
A novel reactive electrochemical flow system consisting of iron anode and porous cathode is proposed for the remediation of mixture of contaminants in groundwater. The system consists of a series of sequentially arranged electrodes, a perforated iron anode, a porous copper cathode followed by a mesh-type mixed metal oxide anode. The iron anode generates ferrous species and a chemically reducing environment, the porous cathode provides a reactive electrochemically reducing barrier, and the inert anode provides proton and oxygen to neutralize the system. The redox conditions of the electrolyte flowing through this system can be regulated by controlling the distribution of the electric current. Column experiments are conducted to evaluate the process and study the variables. The electrochemical reduction on a copper foam cathode produced an electrode-based reductive potential capable of reducing TCE and nitrate. Rational electrodes arrangement, longer residence time of electrolytes and higher surface area of foam electrode improve the reductive transformation of TCE. More than 82.2% TCE removal efficiency is achieved for the case of low influent concentration (< 7.5 mg/L) and high current (> 45 mA). The ferrous species produced from the iron anode not only enhance the transformation of TCE on the cathode...

Integrated Environmental Risk Assessment and Whole-Process Management System in Chemical Industry Parks

Shao, Chaofeng; Yang, Juan; Tian, Xiaogang; Ju, Meiting; Huang, Lei
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
25.79%
Chemical industry parks in China are considered high-risk areas because they present numerous risks that can damage the environment, such as pollution incidents. In order to identify the environmental risks and the principal risk factors in these areas, we have developed a simple physical model of a regional environmental risk field (ERF) using existing dispersal patterns and migration models. The regional ERF zoning was also conducted and a reference value for diagnostic methods was developed to determine risk-acceptable, risk-warning, and risk-mitigation zones, which can provide a risk source layout for chemical industry parks. In accordance with the environmental risk control requirements, this study focused on the three stages of control and management of environmental risk and established an environmental risk management system including risk source identification and assessment, environmental safety planning, early risk warning, emergency management, assessment of environmental effects, and environmental remediation of pollution accidents. By using this model, the environmental risks in Tianjin Binhai New Area, the largest chemical industry park in China, were assessed and the environmental risk zoning map was drawn, which suggested the existence of many unacceptable environmental risks in this area. Thus...

Application of Electro-Fenton Technology to Remediation of Polluted Effluents by Self-Sustaining Process

Fernández de Dios, Maria Ángeles; Iglesias, Olaia; Pazos, Marta; Sanromán, Maria Ángeles
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 26/02/2014 EN
Relevância na Pesquisa
25.89%
The applicability of electro-Fenton technology to remediation of wastewater contaminated by several organic pollutants such as dyes and polycyclic aromatic hydrocarbons has been evaluated using iron-enriched zeolite as heterogeneous catalyst. The electro-Fenton technology is an advanced oxidation process that is efficient for the degradation of organic pollutants, but it suffers from the high operating costs due to the need for power investment. For this reason, in this study microbial fuel cells (MFCs) were designed in order to supply electricity to electro-Fenton processes and to achieve high treatment efficiency at low cost. Initially, the effect of key parameters on the MFC power generation was evaluated. Afterwards, the degradation of Reactive Black 5 dye and phenanthrene was evaluated in an electro-Fenton reactor, containing iron-enriched zeolite as catalyst, using the electricity supplied by the MFC. Near complete dye decolourization and 78% of phenanthrene degradation were reached after 90 min and 30 h, respectively. Furthermore, preliminary reusability tests of the developed catalyst showed high degradation levels for successive cycles. The results permit concluding that the integrated system is adequate to achieve high treatment efficiency with low electrical consumption.

Internet-enabled integrated presentation system for site remediation preliminary assessment

Lukasiak, Anna D
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 95 leaves
ENG
Relevância na Pesquisa
25.75%
by Anna D. Lukasiak.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1997.; Includes bibliographical references (leaves 32-33).

Development of an Integrated Decision Support System for Brownfield Restoration; Entwicklung eines integrierten Entscheidungshilfesystems zur Revitalisierung von Brachflächen

Morio, Maximilian
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
EN
Relevância na Pesquisa
36.28%
The re-use of underused or abandoned contaminated land, so-called brownfields, is increasingly seen as an important means for the reduction of land consumption. But brownfield redevelopment often fails during early project stages due to complex decisions that stakeholder with potentially different interest have to make, based on typically very scarce data. Seeking sustainable re-use solutions, many existing decision support systems are not appropriate as they focus mainly on environmental or economic aspects, and neglect sustainability issues. To fill this gap, this thesis presents a framework for spatially explicit integrated planning and assessment of brownfield redevelopment options. Aiming to support efficient and sustainable revitalization and communication between stakeholders, the presented assessment framework integrates three pinnacles of brownfield revitalization: (i) the identification of required subsurface remediation and associated site preparation costs, (ii) market-oriented economic appraisal, and (iii) the expected contribution of planned future land use to sustainable urban and regional development. For the assessment, focus is set on the early stage of the brownfield redevelopment process, which is characterized by limited data availability and by flexibility in land use planning and scope of development. A convenient starting point for the planning of different land uses and respective remediation measures is the early identification of focal areas with respect to groundwater contamination. %The complexity and scale of groundwater contamination at large brownfields requires an early identification and prioritization of focal areas and risks in order to drive further decisions concerning detailed investigation programmes and remediation measures. There is a need for the enhancement and appropriate processing of sparse amounts of groundwater contamination data...

Microbial community dynamics in anaerobic bioreactors and algal tanks treating piggery wastewater

Patil, S.; Kumar, M.; Ball, A.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
25.88%
Integrated biosystem is becoming a major aspect of wastewater management practice. Microbial communities in piggery wastewater sampled from anaerobic (thermophilic and mesophilic) and aerobic digesters (algal tanks) during waste remediation were analyzed by culture-independent techniques based on polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The use of Muyzer's 314F-GC, 518R bacterial primers, and archaeal A934F, 1309R primers followed by partial 16s rDNA sequence analysis of the main bands from DGGE revealed the presence of unknown and as yet uncultured microorganisms but also showed functional and ecologically significant denitrifying, acetogenic bacteria along with autotrophic, hydrogenotrophic, and acetoclastic methanogen archaea. Thermophilic digesters were dominated by gamma-Proteobacteria, Methanothermobacter sp., while mesophilic digesters showed dominance by Firmicutes, uncultured bacteria, Methanosarcina, and Methanoculleus genera. Under aerobic conditions within algal tanks, pH rose from 7.17 to 9.32, with a significant decrease in total ammonia nitrogen, chemical oxygen demand, and soluble phosphorus levels. PCR-DGGE proved a useful tool for investigating the dynamics of microbial community in the bio-processing of piggery wastewater. Knowledge of the microbial communities involved in digestion of piggery wastewater will allow optimization of integrated biosystem by removing the main pollutants like inorganic ammonium-nitrogen...

Nano/micromaterials and motors in (bio)sensing applications

Guix Noguera, Maria
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis Formato: application/pdf
Publicado em //2013 ENG; ENG
Relevância na Pesquisa
15.9%
El disseny i la caracterització de plataformes analítiques i miniaturitzades, modificades amb diferents nanomaterials (tals com nanotubs de carboni o nanocables), s'ha portat a terme per a la seva posterior aplicació en la detecció de diversos analits d'interès (com per exemple fenol, glucosa, o la captura d'oli). Cal destacar que en alguns casos les plataformes sensores s'han modificat prèviament amb entitats biològiques que aporten selectivitat i sensitivitat a l'estudi analític. Referent als processos en absència de flux (mode batch), el elèctrodes serigrafiats de capa gruixuda (screen-printed electrodes, SPE) s'han modificat amb nanotubs de carboni, demonstrant un comportament analític excepcional per a aplicacions mediambientals. La detecció de fenol, modificat amb l'enzim de Tyrosinasa, va ser caractertizat mitjançant diferents tècniques de microscòpia com SEM, TEM o microscòpia confocal (CSLM), les quals van permetre obtenir una sèrie de dades estadístiques referents a la morfologia del material, alhora que van permetre determinar la distribució de la Tyrosinasa en la matriu sensora. Es van estudiar diferents mètodes d'immobilització, a més a més de ser implementat en un sistema de d'anàlisi per injecció en flux. A més a més...

A framework for integrates hydrologic, sediment and nutrient export modelling for catchment-scale management

Newham, Lachlan; Letcher, Rebecca; Jakeman, Anthony; Kobayashi, Yukiyasu
Fonte: Pergamon-Elsevier Ltd Publicador: Pergamon-Elsevier Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
25.9%
Many catchments in Australia have experienced increased sediment and nutrient loadings and concomitant declines in water quality and increases in problematic blue-green algal blooms over the past several decades. This paper describes an integrated hydrologic, sediment and nutrient export modelling framework known as catchment-scale management of diffuse sources (CatchMODS). The modelling framework is designed to simulate and assess catchment-scale land and water management activities designed to reduce nutrient and sediment delivery to receiving waters. The Ben Chifley Dam Catchment in New South Wales, Australia is used as a case study for describing the development of the framework. Improving water quality through reduction of sediment and nutrient loads will reduce the probability of algal bloom occurrence in the dam. The innovation of the system is the integration of otherwise separate modelling approaches to enable biophysical and economic assessment of different management options. The outputs from the research are used to improve and focus on-ground remediation, targeted to specific stream reaches or subcatchment areas, as well as to encourage sustainable management practices more broadly in the catchment. With minimal modification...

AN INTEGRATED REMEDIATION SYSTEM USING SYNTHETIC AND NATURAL ZEOLITES FOR TREATMENT OF WASTEWATER AND CONTAMINATED SEDIMENTS

RIOS REYES,CARLOS; APPASAMY,DANEN; ROBERTS,CLIVE
Fonte: DYNA Publicador: DYNA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
Relevância na Pesquisa
96.27%
The major sources of water pollution can be classified as municipal, industrial, and agricultural. Different types of polluted aqueous effluents and sediments may be produced, which contain relatively high levels of heavy metals. During the 1990s, the large-scale development of constructed wetlands around the world drew much attention from public and environmental groups. The present study looks at the use of an integrated remediation system using zeolites for the treatment of wastewater and sediments. Zeolites have been widely studied in the past 10 years due to their attractive properties such as molecular-sieving, high cation exchange capacities, and their affinity for heavy metals. Coal industry by-products-based zeolites (faujasite type) have been tested as an effective and low-cost novel alternative for wastewater treatment, particularly their removing of heavy metals. On the other hand, a preliminary laboratory-scale experiment was conducted on the use of natural zeolites (clinoptilolite type) for the retention of heavy metals from canal sediments. Experimental work revealed promising results, which could be replicated on a bigger scale. Although this has been developed for canal sediments, the remediation strategy can be adapted to different waterways such as rivers. The development of the proposed remediation system in a specific experimental site as the major part of an innovation park can provide great benefits to a population living near contaminated effluents. It provides not only opportunities for the mitigation of environmental impact...

Sustainable geohydrological model of San Luis Potosí aquifer, Mexico

Flores-Márquez,E. Leticia; Kohn Ledesma,Ingrid; Arango-Galván,Claudia
Fonte: Instituto de Geofísica, UNAM Publicador: Instituto de Geofísica, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
Relevância na Pesquisa
25.94%
An integrated geophysical and hydrogeological study is carried out on the San Luis Potosí aquifer system and a transient flow model and are proposed alternative exploitation scenarios. The aquifer water balance between recharge and extraction indicates a deficit of 100 Hm³ by the year 2005. A comparison of the historical potentiometric levels recorded between 1972 and 2005 shows a cone of depression 80 m deep extending over an area of 70 km² inside of San Luis Potosí City. The model suggests that the aquifer is sensitive to the locations of extraction wells. Predictive models are developed and remediation measures are proposed as alternatives to current extraction procedures in order for the aquifer system to recover.

Passive remediation of acid mine drainage using cryptocrystalline magnesite: A batch experimental and geochemical modelling approach

Masindi,Vhahangwele; Gitari,Mugera Wilson; Tutu,Hlanganani; De Beer,Marinda
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2015 EN
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25.89%
Acid mine drainage is generated when mining activities expose sulphidic rock to water and oxygen leading to generation of sulphuric acid effluents rich in Fe, Al, SO4 and Mn with minor concentrations of Zn, Cu, Mg, Ca, Pb depending on the geology of the rock hosting the minerals. These effluents must be collected and treated before release into surface water bodies. Mining companies are in constant search for cheaper, effective and efficient mine water treatment technologies. This study assessed the potential of applying magnesite as an initial remediation step in an integrated acid mine drainage (AMD) management system. Neutralization and metal attenuation was evaluated using batch laboratory experiments and simulations using geochemical modelling. Contact of AMD with cryptocrystalline magnesite for 60 min at 1 g: 100 ml S/L ratio led to an increase in pH, and a significant increase in metals attenuation. Sulphate concentration was reduced to =1 910 mg/l. PH redox equilibrium (in C language) (PHREEQC) geochemical modelling results showed that metals precipitated out of solution to form complex mineral phases of oxy-hydroxysulphates, hydroxides, gypsum and dolomite. The results of this study showed that magnesite has potential to neutralize AMD...