Estudo de reatores eletroquímicos para remoção de Cu2+ , Zn2+, Fenol e BTEX em água produzida

The production of water has become one of the most important wastes in the petroleum industry, specifically in the up stream segment. The treatment of this kind of effluents is complex and normally requires high costs. In this context, the electrochemical treatment emerges as an alternative methodology for treating the wastewaters. It employs electrochemical reactions to increase the capability and efficiency of the traditional chemical treatments for associated produced water. The use of electrochemical reactors can be effective with small changes in traditional treatments, generally not representing a significant additional surface area for new equipments (due to the high cost of square meter on offshore platforms) and also it can use almost the same equipments, in continuous or batch flow, without others high costs investments. Electrochemical treatment causes low environmental impact, because the process uses electrons as reagent and generates small amount of wastes. In this work, it was studied two types of electrochemical reactors: eletroflocculation and eletroflotation, with the aim of removing of Cu2+, Zn2+, phenol and BTEX mixture of produced water. In eletroflocculation, an electrical potential was applied to an aqueous solution containing NaCl. For this, it was used iron electrodes, which promote the dissolution of metal ions, generating Fe2+ and gases which, in appropriate pH, promote also clotting-flocculation reactions, removing Cu2+ and Zn2+. In eletroflotation, a carbon steel cathode and a DSA type anode (Ti/TiO2-RuO2-SnO2) were used in a NaCl solution. It was applied an electrical current, producing strong oxidant agents as Cl2 and HOCl, increasing the degradation rate of BTEX and phenol. Under different flow rates, the Zn2+ was removed by electrodeposition or by ZnOH formation, due the increasing of pH during the reaction. To better understand the electrochemical process, a statistical protocol factor (22) with central point was conducted to analyze the sensitivity of operating parameters on removing Zn2+ by eletroflotation, confirming that the current density affected the process negatively and the flow rate positively. For economical viability of these two electrochemical treatments, the energy consumption was calculated, taking in account the kWh given by ANEEL. The treatment cost obtained were quite attractive in comparison with the current treatments used in Rio Grande do Norte state. In addition, it could still be reduced for the case of using other alternative energy source such as solar, wind or gas generated directly from the Petrochemical Plant or offshore platforms

Efeitos de absorventes de umidade e de aditivos químicos e microbianos sobre o valor nutritivo, o perfil fermentativo e as perdas em silagens de capim-marandu

The objective of this trial was to evaluate the nutritional value, fermentation profile and dry matter losses of Palisadegrass silages ensiled with either dried citrus pulp, soybean hulls, chemical or microbial additives. The trial was carried out in a completely randomized experimental design and in a factorial arrangement (3 x 5), with three dry matter levels (wet forage or forage ensiled with pelleted citrus pulp or pelleted soybean hulls) and five additives (without or with the presence of bacterial inoculants or the addition of: sodium benzoate, formic acid in the concentration of 62% or 44%), totalizing 15 treatments and 60 experimental silos. The variables analyzed were: nutritional value, losses due to gases and effluents, and dry matter recovery. The use of dried citrus pulp or soybean hulls at the ensiling time increased the dry matter content (29.4 and 28,9%) and decreased the effluent production (4.1 and 3.8 kg/t of fresh matter), also providing fermentable substrate to microorganisms, resulting in increased fermentation coefficient and digestibility of silages. The use of formic acid resulted in silages with higher digestibility and increased water-soluble carbohydrates and crude protein content. This additive was also effective in reducing the losses due to gases and, as a result, increased the total dry matter recovery. The treatment containing homolactic bacteria showed similar trend of increasing the digestibility and reducing the losses due to gases. The use of sodium benzoate was less effective in altering the fermentation pattern of tropical silages. The nutritional value and total dry matter losses of silages ensiled without additives can be considered satisfactory. However, wet forage ensiled with dried citrus pulp and, mainly, with soybeans hulls showed the best results. Treatments containing formic acid had a beneficial effect on the fermentation profile of tropical grass silages.

Sintered Sewage Sludge As Support Material Used In Drinking Water Filtration

The processing of industry and domestic effluents in wastewater treatment plants reduces the amount of polluted material and forms reusable water and dehydrated sludge. the generation of hazardous municipal sludge can be decreased, as well as the impact on surface and underground water and the risk to human health. The aim this study is to verify the possibility to use sintered sewage sludge as support material after thermal treatment in the production of a filtering material to water supply systems. After thermal treatment the sewage sludge ash was characterized by X-ray fluorescence (XRF), leaching test and water solubilization. Dehydration of sludge was performed by controlled heating at temperatures of 180 degrees C, 350 degrees C, 600 degrees C, 850 degrees C and 1000 degrees C for 3 hours.

ESR dating of pleistocene mammal teeth and its implications for the biostratigraphy and geological evolution of the coastal plain, Rio Grande do Sul, southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eutrofização e qualidade da água na piscicultura: consequências e recomendações

The eutrophication (cultural or anthropogenic) is induced by man and can have different origins, such as domestic sewage, industrial and agricultural activities, including the effluent still breeding systems of aquatic organisms. The expansion of aquaculture, with production of biomass and increase of nutrients in water may cause acceleration of productivity of algae, changing the ecology of aquatic systems. In addition, these waste water may present a risk to health through the transfer of pathogens from manure, plant residues, composted material, among others that are major sources of organic waste in some farming systems. Depending on the trophic level of fish ponds, which are dynamic environments, different planktonic species with short reproductive cycle and adapted to the changes contained in these systems can appear in high abundance. Water quality in the systems for raising fish is related to several factors, such as water source, management (liming, fertilizing, cleaning), cultivated species and quantity and composition of exogenous food. In order to minimize environmental impacts, there are techniques to improve the quality of water in fish farming systems and thus satisfactory answers can be obtained through the application of management practices. This paper aims to review the subject that deals with changes in water quality resulting from the activity of freshwater fish culture in Brazil. Search also recommend techniques of good management practices to minimize the impact generated by the activity.

Toxicity of the therapeutic potassium permanganate to tilapia Oreochromis niloticus and to non-target organisms Ceriodaphnia dubia (microcrustacean cladocera) and Pseudokirchneriella subcapitata (green microalgae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biodigestão anaeróbia dos dejetos de cabritos Saanen alimentados com dietas com diferentes proporções volumoso e concentrado

Avaliaram-se os efeitos da idade do animal e da proporção de volumoso nas dietas sobre a biodigestão anaeróbia dos dejetos de cabritos Saanen. Foram utilizadas as fezes produzidas por cabritos Saanen aos 90, 120 e 150 dias de idade e alimentados com dietas de três relações volumoso:concentrado (80:20, 60:40 e 40:60), representando as dietas 1, 2 e 3, respectivamente. Utilizaram-se biodigestores tipo batelada de bancada com capacidade para 12 litros de substrato em fermentação e 8% de sólidos totais iniciais para determinação das produções e dos potenciais de produção de biogás e metano, da redução de sólidos voláteis e quantificação dos teores de minerais no afluente e efluente. As maiores reduções de sólidos voláteis foram observadas nos substratos preparados com as fezes de cabritos aos 150 dias alimentados com a dieta com relação volumoso:concentrado de 40:60. Os melhores rendimentos de substrato ou fezes foram obtidos com os dejetos dos cabritos de 120 e 150 dias de idade alimentados com a dieta com relação volumoso:concentrado 40:60. As maiores concentrações de minerais nos biodigestores foram observadas para as fezes de cabritos de 150 dias de idade alimentados com a dieta com relação volumoso:concentrado 40:60. A biodigestão anaeróbia é eficiente na remoção de coliformes nos dejetos de caprinos, proporcionando efluentes com no máximo 4,3 × 10² coliformes totais termotolerantes por grama de material.

Poder poluente de águas residuárias de suinocultura após utilização de um tratamento integrado

Em experimento de campo, avaliou-se o potencial de impacto ambiental de águas residuárias de suinocultura, acondicionadas em um tanque de estocagem, com distintos tempos de retenção hidráulica e aplicadas, posteriormente, em lisímetros preenchidos com solos arenosos, argilosos e de texturas médias. Para tal, foram determinados os valores de pH nos solos e as quantificações das concentrações de zinco e cobre na água residuária in natura e, após os quatro tempos de retenção hidráulica do tanque de estocagem, nos percolados dos lisímetros e nos solos. Os resultados mostram que a estocagem não foi eficiente na redução, aos níveis exigidos pela legislação, das concentrações de zinco e cobre nos efluentes do tanque de estocagem. A aplicação no solo gerou reduções eficientes nas concentrações de zinco e cobre. Por fim, enfocando a contribuição fertilizante destas águas residuárias, o solo argiloso foi o mais beneficiado com este sistema integrado de tratamento, contribuindo para a redução das concentrações de zinco e cobre para valores abaixo dos permitidos pelas legislações, o que protegeria o lençol freático da contaminação por esses dois metais pesados.

Redução de Bactérias Indicadoras de Poluição Fecal em Estrume de Aves de Postura Tratados por Biodigestão Anaeróbia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise de efluente e histologia da pele, fígado e rim de Pacus (Piaractus mesopotamicus) suplementados com cromo trivalente

The objective of this work was to evaluate the skin, liver and kidney histology of young pacus supplemented in diet with trivalent chromium and to evaluate the residue of chromium in water effluent. Randomised delineation by using factorial scheme 4x2, with four levels of chromium (0, 6, 12, 18 mg/L), two stocking densities (4 and 20 kg/m(3)), and four repetitions were used. Pacus with 100 g were used, for 90 days. An increase of the number of mucus cells and club cells in the epidermis of the pacus supplemented with 18 chromium mg/kg was observed in any stocking density. The same effect was observed in the liver, and in the highest density (20 kg/m(3)) the alterations already occurred at the level of 6 mg/kg with the inclusion of chromium, initially with congestion of sinusoids and getting worse at the level of 18 mg/kg with necrosis. The kidney didn't present visible morphologic alterations when supplemented and submitted to the stocking densities. The concentration of chromium in the effluent of pacus was 3.27 mu g/L in the higher level of supplementation (18 mg/L). In conclusion the level of 18 supplement mg/kg was not shown beneficial to the growth of pacus and the stocking density, due to the possible stress, accelerated the alteration histology process of tissues.

Sistema de gestão ambiental na produção de água mineral

It s more and more evident the subject of the shortage of water, worsened by the accelerated urbanization, growth of the population, increase of the demand and of the costs of its treatment, factors that are also tied up to the increase of the consumption of mineral waters, whose chemical composition or physical-chemistries characteristics do with that are considered beneficial to the health. The growth accelerated all over the world in its consumption aims the concern with the waters quality, the health and the incentive to the consumption of natural products. However, in spite of quite valuable, that resource is explored, most of the time, without optimization of production or actions that avoid wastefulness. This research is justified for the need of minimizing the negative environmental impacts caused by the mineral water s production, mainly in what it say about the generation of effluents and wastes in the productive process, through the study, development and application of cleaner production tools for the environmental management, pertinent for that section. The applicability of Environmental Management System was determined by means of the characterization of the environmental aspects of productive process in a company of the section, in the state of Rio Grande do Norte and of the discussion of the panoramas that demonstrate the tendency for a sustainable development. Actions as a reforestation, optimization of energy and water uses, recycle of solid residues and water reuse were applied during the research, resulting in the considerable reduction of wastes of raw materials and inputs and consequent environmental and economic won. A specific methodology was proposed with concepts of Environmental Management, integrating with Quality Management. As foundations for the elaboration of the methodology, it was realized a similarity analysis among the systems and, mainly, an analysis of the experiences observed in the case study, including specificities, needs and difficulties of the company. With these results, the implantation of a EMS as a company strategy has environmental, economic and social benefits, and this research can be applied and adequate to others companies and sectors

Perdas de silagens de cana-de-açúcar tratadas com aditivos químicos e bacterianos

Objetivou-se avaliar silagens de cana-de-açúcar tratadas com aditivos químicos (uréia 1,5%; benzoato de sódio 0,1%; ou hidróxido de sódio (NaOH) 1% na matéria natural) combinados ou não com inoculantes (Propionibacterium acidipropionici + Lactobacillus plantarum ou Lactobacillus buchneri). Foram avaliadas 12 silagens: uma controle, sem inoculante e sem aditivo químico; três sem inoculante, mas com um dos aditivos; uma com P. acidipropionici + L. plantarum, sem aditivo químico; três com P. acidipropionici + L. plantarum e um dos aditivos; uma com L. buchneri, sem aditivo químico; e três com L. buchneri e um dos aditivos. Os dados foram analisados em esquema fatorial 4 × 3 com três repetições para cada tratamento. Foram determinadas as perdas ocorridas durante o processo fermentativo nas formas de gases e de efluentes e a recuperação da MS. Durante a exposição aeróbia, determinaram-se a recuperação da MS e a estabilidade aeróbia medida pela variação da temperatura. A associação de L. buchneri e NaOH reduziu as perdas por gases e efluentes e elevou a recuperação da MS. No período após abertura, destacou-se a atuação do benzoato de sódio em manter o pH com variação de apenas 0,1 unidade em cinco dias de exposição aeróbia e dos inoculantes L. buchneri e P. acidipropionici + L. plantarum em prolongar o tempo para elevação da temperatura de 34 horas nas silagens controle para 54 e 50 horas, respectivamente. A ensilagem de cana-de-açúcar requer a inclusão de algum aditivo eficiente no controle das perdas quantitativas durante a fermentação e a exposição aeróbia.

Desenvolvimento de nanocompósito (hidroxiapatita/ poliuretano) pela gelação (gelling) de poli ( álcool vinílico) (PVA) para remoção de metais pesados

Removing microcontaminants from effluents is a challenge today, because of its high cost and low efficiency, especially in the treatment of effluents containing heavy metals. An alternative that has emerged is the use of biodegradable nanocomposites, which exhibit good removal and recovery performances, in addition to its low cost. With this in mind, the present study aimed to develop and characterize a nanocomposite based on hydroxyapatite (HAP), polyurethane (PU) and polyvinyl alcohol (PVA) for removing heavy metals. Thus, the research was conducted in several steps: i)- Physico-chemical and microbiological hospital effluent characterization; ii)- Production of hydroxyapatite by aqueous precipitation technique, and their characterization; iii)- Production of the nanocomposite in which the hydroxyapatite was added to the polyurethane prepolymers and then the polyvinyl alcohol/hydroxyapatite film was produced; iv)- Polyvinyl composite without film PU/HAp was also produced in the proportions of 20 and 40% HAp; v)- The composites was characterized by the techniques of XRD, FTIR, SEM / EDS, BET, Zeta Potential and TGA; vi)- The sisal and coconut fibres were washed and dried for comparative tests of adsorption; vii)- Adsorption tests for evaluating the removal of heavy metals (nickel and cadmium). Initial screening adsorption capacity (HAp; PU/HAp - 20 and 40%; PU / HAp / PVA), kinetic studies of adsorption of Cd (II) by HAp; multifactorial design analysis (factorial design) for identifying the most important variables in the adsorption of Cd (II) by composite PU/HAp. Also comparative analysis of adsorption of Cd and Ni by composite PU/HAp were conducted, as well as comparative tests of adsorption of Cd (coconut fibre) and Ni (sisal fibre). It was possible to verify that the composite PU/HAp 40% showed better effectiveness for the removal of Cd (II) and Ni (II), above 80%, equivalent to the lignocellulosic fibre used and HAp produced. As main conclusion, it can be referred that the composite PU/HAp 40% is an effective adsorvent to wastewater treatment for heavy metal removal, with low cost and high efficiency

Análise da influência de superfícies refletivas nas perdas de calor de sistema térmicos

The use of reflective surfaces functioning as thermal insulator has grown significantly over the years. Reflective thermal insulator are materials that have several characteristics such as low emissivity, low absorptivity and high reflectivity in the infrared spectrum. The use of these materials has grown a lot lately, since it contains several important radioactive properties that minimize the heat loss of thermal systems and cooling systems that are used to block the heat on the roof of buildings. A system made of three surfaces of 316 stainless steel mirror was built to analyze the influence of reflective surfaces as a way to reduce the heat loss and thereby conserve the energy of a thermal system. The system was analyzed both with and without the presence of vacuum, and then compared with a system that contained glass wool between the stainless steel mirror walls, since this isolator is considered resistive and also broadly used around the world in thermal systems. The reflectivity and emissivity of the surfaces used were also measured in this experiment. A type K thermocouple was fixed on the wall of the system to obtain the temperature of the stainless steel mirror surfaces and to analyze the thermal behavior of each configuration used. The results showed an efficiency of 13% when the reflective surfaces were used to minimize the heat loss of the thermal system. However, the system with vacuum had the best outcome, a 60% efficiency. Both of these were compared to the system made of glass wool as a thermal insulator

Remoção de óleo da água de produção por flotação em coluna utilizando tensoativos de origem vegetal

In the petroleum industry, water is always present in the reservoir formation together with petroleum and natural gas and this fact provokes the production of water with petroleum, resulting in a great environmental impact. Several methods can be applied for treatment of oily waters, such as: gravitational vases, granulated media filtration systems, flotation process, centrifugation process and the use of hydrocyclones, which can also be used in a combined way. However, the flotation process has showed a great efficiency as compared with other methods, because these methods do not remove great part of the emulsified oil. In this work was investigated the use of surfactants derived from vegetable oils, OSS and OGS, as collectors, using the flotation process in a glass column with a porous plate filter in its base for the input of the gaseous steam. For this purpose, oil/water emulsions were prepared using mechanical stirring, with concentrations around 300 ppm. The air flow rate was set at 700 cm3/min and the porous plate filter used for the generation of the air bubbles has pore size varying from 16 to 40 Pm. The column operated at constant volume (1500mL). A new methodology has been developed to collect the samples, where, instead of collecting the water phase, it was collected the oil phase removed by the process in the top of the flotation column. It has been observed that it is necessary to find an optimum surfactant concentration to achieve enhanced removal efficiency. Being for OSS 1.275 mmol/L and for OGS 0.840 mmol/L, with removal efficiencies of 93% and 99%, respectively, using synthetic solutions. For the produced water, the removal in these concentrations was 75% for OSS and 65% for OGS. It is possible to remove oil from water in a flotation process using surfactants of high HLB, fact that is against the own definition of HLB (Hydrophile-Lipophile Balance). The interfacial tension is an important factor in the oil removal process using a flotation process, because it has direct interference in the coalescence of the oil drops. The spreading of the oil of the air bubble should be considered in the process, and for the optimum surfactant concentrations it reached a maximum value. The removal kinetics for the flotation process using surfactants in the optimum concentration has been adjusted according to a first order model, for synthetic water as for the produced water.