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No description available.

O presente estudo objetivou a caracterização hidrogeoquímica da microbacia de drenagem Entre Rios, reflorestada com eucaliptos utilizando-se modelos de transporte de materiais nas fases dissolvidas e particuladas, em períodos de amostragens, antes e depois da realização da colheita de madeira. Na área experimental foram coletadas amostras de águas fluviais, material particulado em suspensão, águas de chuva, solos e sedimentos de fundo. Foram determinados importantes parâmetros e variáveis como vazão, concentração de íons majoritários e material particulado em suspensão, variabilidade temporal e transportes de material dissolvido e particulado, mecanismos de aporte difuso e pontual da carga dissolvida, separação das componentes superficial e subterrânea no escoamento total, concentração e biodisponibilidade dos principais metais pesados nos solos e sedimentos de fundo do córrego. As características hidroquímicas das águas fluviais mostraram que as espécies químicas SiO2, HCO3 -, Ca2+, Mg2+ e Na+ apresentaram comportamentos de diluição com o aumento da vazão e aportes de origem difusa, em todo período, relacionadas à formação geológica da região e mecanismos de recarga da bacia. A amostragem realizada cinco meses após a colheita de madeira evidenciou anomalias de K+ e Cl- que apresentaram padrões de aumento de suas concentrações em relação ao aumento das respectivas vazões, associadas à aplicação de insumos agrícolas. O transporte específico de TDS na amostragem anterior à colheita foi de 35,81 kg km-2d-1, e posterior à colheita foi de 23,53 kg km-2d-1 pelo método estocástico. Tal transporte foi composto principalmente de SiO2 e HCO3 - e a origem destas espécies estiveram associadas à alterações de rochas e aportes atmosféricos totais. Em termos de MPS, as concentrações obtidas se relacionaram positivamente com a vazão nas amostragens intensivas indicando maiores arrastes deste material nas maiores vazões, com concentrações máximas de 50,2 e 80,6 mg L-1 antes e após a colheita, respectivamente. A erosão mecânica da microbacia mostrou-se com uma taxa de degradação física dos solos de 8,7 m Ma-1.Em relação aos aportes atmosféricos, as espécies químicas mais representativas foram o Ca2+ e o Na+ para os cátions e HCO3 -, NO3 - e SO4 2- para os ânions. O transporte específico do TDS nas águas de chuva foi de 4,10 t km-2 a-1. Pelas razões dos transportes totais de águas pluviais e fluviais ficou evidenciado um controle dos aportes atmosféricos totais sobre as águas do córrego da microbacia. Cr, Cd, Co, Cu, Zn e Sc foram os metais pesados com maiores concentrações no solo LVd da microbacia. A especiação química dos solos revelou que o LVd foi solo que apresentou maior fração biodisponível para Cd e Zn e estiveram associados principalmente as frações óxidos de ferro cristalino e matéria orgânica, respectivamente. Os resultados dos fatores de enriquecimento para as camadas de 0-10 cm dos solos da microbacia de drenagem não evidenciaram influência antrópica causada pelos tratos culturais, exceto pelo Cu no solo LVAd na camada de 0-10 cm / This study aimed to characterize the Entre Rios stream small watershed hydrogeochemistry, reforested with eucalyptus using materials transport models in dissolved and particulate phases, in periods of sampling, before and after the clearcutting. In the experimental area were collected river water samples, suspended particulate material, rain water, soil and botton sediments. Were determined important parameters and variables such as discharge, major íons concentration, and suspended particulate material, temporal variability and dissolved and particulate transports, punctual and diffuse input mechanisms of the dissolved load, superficial and sub superficial components of the total discharge, concentration and bioavailability of the major heavy metals in soils and bottoms sediments. Hydrochemistry characteristics of the fluvial waters showed that chemical species SiO2, HCO3 -, Ca2+, Mg2+ and Na+ presented dilution behavior with increasing of the discharge and diffuse input, in any period, related to the regional geological formation and watershed recharge mechanisms. Sampling performed five months after the clearcutting showed abnormalities of K+ and Clthat showed increase of their concentrations with the discharge, associated with the agricultural inputs application. The TDS specific transport in the sample before clearcutting was 35.81 kg km-2d-1, and after was 23.53 kg km-2d-1 calculated by the stochastic method. This transport was composed mainly of the SiO2 and HCO3 - and the origin of these species were associated with rock alterations and total atmospheric inputs. In terms of MPS, the concentrations were related positively with the discharge in intensive sampling indicating more haul of this material in the higher discharge with maximum concentrations of the 50.2 and 80.6 mg L-1 before and after clearcutting, respectively. The mechanical erosion showed a soil physical degradation tax of the 8.7 m Ma-1. In relation of atmospherics inputs, the most representative chemical species were Ca2+ and Na+ and HCO3 -, NO3 -, SO4 2-. The TDS specific transport in rain waters was 4.10 t km-2 y-1. The rations between rainwater and river transports demonstrated the control of the atmospheric total contributions in the watershed waters. Cr, Cd, Co, Cu, Zn and Sc were heavy metals with higher concentrations LVd in soil. The soils chemical speciation showed to the LVd soil higher bioavailable fraction for Cd and Zn and were associated mainly with crystalline iron oxides and organic matter, respectively. The enrichment factors results for the 0-10 cm soil layer in the watershed showed no anthropogenic influence caused by cultural treatments, except for the Cu in 0-10 cm LVAd soil layer

Alguns estudos do emprego de compostos de ferro como material adsorvedor não- convencional são citados em literatura. Foram feitos alguns testes da utilização de hematita (Fe2O3), o lodo galvânico e a lama de alto forno como adsorvedores para a remoção de metais pesados de efluentes industriais. A utilização de resíduo siderúrgico abundante, composto predominantemente por magnetita (Fe3O4), como adsorvedor não - convencional em processos de remoção de metais representa uma alternativa, de baixo custo, para o tratamento e adequação do efluente aos padrões de descarte de efluentes industriais exigidos pela legislação. Neste trabalho estudou-se a utilização de resíduo siderúrgico composto basicamente por magnetita como material adsorvedor para remoção de metais pesados em solução. O trabalho se concentrou no estudo da adsorção de quatro metais: cobre (Cu2+) , níquel (Ni2+) , chumbo (Pb2+) e o cádmio (Cd2+). Estes metais foram escolhidos devido a sua alta toxicidade e por estarem freqüentemente relacionados com efluentes de atividades industriais poluidoras. Os resultados obtidos permitiram concluir que, nas melhores condições de adsorção, o resíduo apresenta características adsorvedoras favoráveis a sua utilização industrial, com 97,84 % de remoção dos íons de cobre, 96,20 % de íons de chumbo, 61,70 % de íons de níquel e 87,22 % de íons de cádmio em solução. A velocidade de adsorção é proporcional a aquelas obtidas para outros adsorvedores não convencionais, e para a remoção dos íons de chumbo varia entre (92 e 115) 10-3mg g1 min-1 , e o sistema de adsorção possui características espontâneas e endotérmicas em adsorção ativada com característica parcial de adsorção química e está de acordo com os modelos propostos por Langmuir e por Freundlich, característico de processo de adsorção em monocamada, com sítios de adsorção de mesma energia e calor de adsorção equivalente. / Various references on the use of ferrous compounds as non - conventional adsorption materials can be found in literature. According to the literature, such materials as hematite, galvanic slag and blast furnace slag were successfully used in liquid waste treatment for heavy metals removal. Thus, the use of abundant ferrous metallurgy slag may prove to be efficient for low cost treatment of liquid industrial waste. The main goal of the present work is the study of converter slag application as adsorber material for heavy metals removal from liquid waste. The present research was aimed at soluble copper ( Cu2+), nickel ( Ni2+ ) , cadmium ( Cd2+ ) , and lead (Pb2+) removal. These metals were chosen because of their high toxicity, and because they are considered as the most common pollutants present in liquid industrial waste. The obtained results on converter slag adsorption properties under optimized adsorption conditions show that 97,84 % of copper, 61,70 % of nickel, 87,22 % of cadmium and 96,20 % of lead can be removed from the liquid waste. The achieved adsorption rates are comparable to those of conventional adsorbers, and for soluble lead removal rates in the range of ( 92 - 115). 10 -3 mg g -1 min -1 were established. Additionally, if was shown that the investigated adsorption system presented spontaneous and endothermic behavior under conditions of activated adsorption with partial chemical adsorption characteristics. Such pattern is in good agreement with the models proposed by Langmuir and Freundlich for monolayer adsorption processes with adsorption centers having equal energy and specific heat of adsorption. Overall, the obtained results indicate the viability of the investigated material for commercial application.

Alguns estudos do emprego de compostos de ferro como material adsorvedor não- convencional são citados em literatura. Foram feitos alguns testes da utilização de hematita (Fe2O3), o lodo galvânico e a lama de alto forno como adsorvedores para a remoção de metais pesados de efluentes industriais. A utilização de resíduo siderúrgico abundante, composto predominantemente por magnetita (Fe3O4), como adsorvedor não - convencional em processos de remoção de metais representa uma alternativa, de baixo custo, para o tratamento e adequação do efluente aos padrões de descarte de efluentes industriais exigidos pela legislação. Neste trabalho estudou-se a utilização de resíduo siderúrgico composto basicamente por magnetita como material adsorvedor para remoção de metais pesados em solução. O trabalho se concentrou no estudo da adsorção de quatro metais: cobre (Cu2+) , níquel (Ni2+) , chumbo (Pb2+) e o cádmio (Cd2+). Estes metais foram escolhidos devido a sua alta toxicidade e por estarem freqüentemente relacionados com efluentes de atividades industriais poluidoras. Os resultados obtidos permitiram concluir que, nas melhores condições de adsorção, o resíduo apresenta características adsorvedoras favoráveis a sua utilização industrial, com 97,84 % de remoção dos íons de cobre, 96,20 % de íons de chumbo, 61,70 % de íons de níquel e 87,22 % de íons de cádmio em solução. A velocidade de adsorção é proporcional a aquelas obtidas para outros adsorvedores não convencionais, e para a remoção dos íons de chumbo varia entre (92 e 115) 10-3mg g1 min-1 , e o sistema de adsorção possui características espontâneas e endotérmicas em adsorção ativada com característica parcial de adsorção química e está de acordo com os modelos propostos por Langmuir e por Freundlich, característico de processo de adsorção em monocamada, com sítios de adsorção de mesma energia e calor de adsorção equivalente. / Various references on the use of ferrous compounds as non - conventional adsorption materials can be found in literature. According to the literature, such materials as hematite, galvanic slag and blast furnace slag were successfully used in liquid waste treatment for heavy metals removal. Thus, the use of abundant ferrous metallurgy slag may prove to be efficient for low cost treatment of liquid industrial waste. The main goal of the present work is the study of converter slag application as adsorber material for heavy metals removal from liquid waste. The present research was aimed at soluble copper ( Cu2+), nickel ( Ni2+ ) , cadmium ( Cd2+ ) , and lead (Pb2+) removal. These metals were chosen because of their high toxicity, and because they are considered as the most common pollutants present in liquid industrial waste. The obtained results on converter slag adsorption properties under optimized adsorption conditions show that 97,84 % of copper, 61,70 % of nickel, 87,22 % of cadmium and 96,20 % of lead can be removed from the liquid waste. The achieved adsorption rates are comparable to those of conventional adsorbers, and for soluble lead removal rates in the range of ( 92 - 115). 10 -3 mg g -1 min -1 were established. Additionally, if was shown that the investigated adsorption system presented spontaneous and endothermic behavior under conditions of activated adsorption with partial chemical adsorption characteristics. Such pattern is in good agreement with the models proposed by Langmuir and Freundlich for monolayer adsorption processes with adsorption centers having equal energy and specific heat of adsorption. Overall, the obtained results indicate the viability of the investigated material for commercial application.

Large scale biofuel production from microalgae is expected to be integrated with point source CO2 sources, such as coal fired power plants. Flue gas (CO2) integration represents a required nutrient source for accelerated growth while concurrently providing an environmental service. Heavy metals inherent in coal will ultimately be introduced into the culture system. The introduced heavy metals have the potential to bind to microalgae cells, impact growth due to toxicity, and negatively impact the quality of biofuel and other microalgal derived products. Heavy metals As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se, Sn, V and Zn, commonly present in coal, were introduced to the microalgae growth medium at a concentration expected from a 7 day growth period using coal flue gas. Experimentation was conducted with Nannochloropsis salina cultivated in photobioreactors at a light intensity of 1000 μmol m-2 s-1. Heavy metals negatively impacted the growth with the average productivity being 0.54 ± 0.28 g L-1 d-1, corresponding to a decrease of 52% in biomass yield compared to control growths. Heavy metal analysis showed significant binding of the majority of the heavy metals to the biomass. A lipid content analysis found a decrease in lipid content from 38.8 ± 0.62% to 31.58 ± 0.50% (percent dry biomass). Control and heavy metal contaminated biomass were processed into biofuel through one of two different in-situ transesterification techniques, either acid-catalyzed or supercritical methanol conversion. The acid-catalyzed conversion resulted in an average crude biofuel production decrease from 0.31 ± 0.03 grams biofuel/gram microalgae for the control algae to 0.28 ± 0.02 grams biofuel/gram microalgae for the heavy metal algae, representing a 9.7% reduction. Supercritical methanol conversion exhibited a similar trend corresponding to a 15.8% reduction. Compared to the control, the total production of biofuel from the contaminated system was decreased by 51% for the acid-catalyzed conversion and 55% for the supercritical methanol conversion. Heavy metal analyses were performed on the biofuel, lipid extracted algae, and other biofuel conversion byproducts. Biochemical methane potential testing was performed on the lipid extracted algae to determine the effect of heavy metals on the generation of biogas. The effects of heavy metals in combination with the effects of acid catalyzed transesterification were found to have a positive effect on the amount of methane produced with an average productivity of 105.89 mL g-COD-1 from the heavy metals contaminated LEA compared to the control microalgae biomass which produced 53.25 mL g-COD-1.

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Soil Washing is a promising alternative treatment method for contaminated site remediation. An industry contaminated site - the OMEX site was selected for the study, and several extraction additives (chelating agent and surfactant) were used to investigate the application of soil washing for the removal of heavy metals and hydrocarbons. The interactions and transport of the contaminants were studied by bench-scale experiments for both heavy metals and hydrocarbons. Soil characterization was performed before the experiments.The soil characterization indicated that the OMEX soil contained large amounts of Pb, Zn (heavy metal) and total petroleum hydrocarbons (TPH). The contaminant concentrations were 986 mg/kg of Pb, 284 mg/kg of Zn, and 29000 mg/kg of TPH. The contaminated soil was also high in moisture content, organic content and total organic carbon (TOC). From soil analyses on different particle size fractions, most contaminants were concentrated in the fine soil fraction, below 150gm, which constituted about 35% by weight of the contaminated soil.Heavy metal removal by chelating agents was conducted first. The results showed that 3% EDTA solution offered the highest removal efficiency for both Pb and Zn. About 90% of Pb and 65% of Zn were removed by using 3% EDTA solution for 29 hours. The extraction kinetics proved to be slow, reaching equilibrium in a relatively long time (more than 10 hours). In soil washing the solution pH had some effect on the removal of both Pb and Zn with marginally better removals observed at a lower pH. The experimental study indicated that the ratio of washing solution volume to soil weight (LIS) had little effect on the percentage removal of both Pb and Zn.In hydrocarbons removal tests, experiments verified that surfactant solutions can be effective in removing organics from coarse soil fraction, while some amount of surfactants were ++ / adsorbed by fine soil particles. Anionic surfactants such as SIDS exhibited less sorption capacity than nonionic surfactants due to the electrostatic repulsion of the former. 4% SDS solution had the highest TPH removal efficiency for OMEX soil, but the 2% SIDS solution was used as it produced only marginally lower results than the 4%. The percentage removal of TPH was about 78% by using 2% SIDS solution. The TPH removal by SDS solution was observed to be a slow and non-equilibrium process. Higher solution temperature can improve removal efficiency of TPH from OMEX soil. Combined washing with a chelating agent and a surfactant was effective in removing both heavy metals and hydrocarbons. Removals of 78% Pb, 82% Zn and 81% TPH were obtained from OMEX soil in the combination test. However, the TPH concentration in fine soil was still very high after washing and would need further treatment.

In the light of increasing demand and diminishing supplies a sustainable urban water management for Melbourne and other cities will need to include water recycling and reuse of reclaimed water and stormwater. One key issue in stormwater reuse is the need for storage between times of collection until times of demand. Aquifer storage and recovery (ASR) would be a valuable option as it has limited space requirements and restricts loss from evaporation. However, stormwater commonly contains elevated levels of heavy metals, of which Zn and Cu are the most mobile. Stormwater also contains suspended solids, organic carbon, oxygen and nutrients, which influence the behaviour of injected metals and induce geochemical changes in the aquifer. While stormwater ASR has been practiced in limestone aquifers in South Australia, field data for sandy aquifers, which are more prevalent around Melbourne, are very limited. Risk assessment regarding the potential impact of stormwater ASR on the quality of the aquifer and groundwater resources in sandy aquifer is therefore necessary. After a characterisation of stormwater from different Melbourne catchments confirmed comparatively high concentrations of Zn and Cu in stormwater, three siliceous aquifer sediments were used in a series of batch sorption experiments as well as column experiments imitating one ASR cycle to assess the impact of different parameters on Zn and Cu behaviour. The reactive geochemical transport model PHT3D was then modified to simulate experimental results with the outlook that it could be used as a predictive tool for long term evaluation. The study showed that Zn adsorption was limited and desorption of large fractions occurred, indicating that injected amounts of Zn are mobile and would mainly be recovered. In contrast, Cu adsorption was higher and desorption was limited, indicating that injected amounts of Cu would mainly accumulate in the aquifer. The release of metals was triggered by reduction in pH, increase in ionic strength and particle mobilisation. Metal concentrations were also increased after storage phases, while minor sediment constituents, especially organic matter, significantly reduce metal mobility. The different role of dissolved and solid organic carbon is critical in understanding Cu behaviour during stormwater ASR. Pretreatment of stormwater to reduce the injection of colloids, organic carbon and metals are recommended to limit metal accumulation in the subsurface. Monitoring of water quality throughout the ASR cycle would be encouraged to validate the current findings with field data. Special attention should be paid to backflushed water quality to ensure correct disposal.

Heavy metals present in high concentrations in aquatic habitats are bioaccumulated within the tissues of intertidal organisms. The chemical analyses of animal tissues and sediments provide an indication of bioavailability of heavy metals in the environment. Monitoring of the coastal pollution using organisms is widely practiced all over the world.Chemical analysis of the tissues of Pacific oyster, Crassostrea gigas, and river sediments were used in this study to monitor the environmental concentrations, of cadmium, copper, lead and zinc of shallow coastal areas near to the river mouths of Mahurangi, Awaruku, Waiake, Taiorahi and Wairau. All of these river mouths are situated along the northeastern coast of Auckland. Each month, during the period of November 2002 to October 2003, three replicate samples of oysters, and sediments were collected from each of the river mouths for analysis. Three additional replicate samples of oysters were collected separately, in each month in order to calculate the condition index of oysters. Oyster tissues and sediments were analysed with Inductively Coupled Atomic Plasma Emission Spectrometer to detect the concentration levels of cadmium, copper, lead and zinc.The highest level of copper and zinc concentrations in the oyster tissues was observed in the river mouth of Wairau. Wairau river mouth receives water from heavily urbanised and industrialised catchments. A higher concentration of cadmium was observed in the oysters of the river mouth of Mahurangi than in the oysters in the other sites. The reason for this difference could be due to the heavy use of cadmium contaminated fertilizers at the pasture lands situated around the Mahurangi estuary. Therefore, the relationship between the land use of the catchments and the degree of pollution of the estuarine habitats could be established from the data obtained from this study. Higher concentrations of heavy metals were found in the sediments of Waiake, Taiorahi and Wairau compared to the sediments of Mahurangi and Awaruku. Significantly higher level of copper was observed in the sediments of Awaruku. However no clear co-relation was found between heavy metal concentration in oysters and in sediments. Variations of the condition of oysters were closely related to seasonal changes of the life cycle of the oysters. No clear relationship was found between the condition of the oysters and the heavy metal concentration of the river mouth habitats.This study provides evidence that Pacific oysters are good organisms to use as bioindicators of environmental heavy metal levels in shallow coastal waters. The results of this study suggest a clear relationship between the heavy metal concentration in river waters and the land use of the catchment areas of those rivers. The results may be useful in management strategies of the northeastern coastal areas of Auckland.