Remoção biológica de nitrato em água de abastecimento humano utilizando o endocarpo de coco como fonte de carbono

The groundwater quality has been compromised as a result of the intensification of human activities over the years. Groundwater contamination by nitrate is one of the effects of this degradation, a socio-environmental problem that affects many regions of the world and particular the city of Natal (RN). Developing techniques for nitrate removal in water is intended to eliminate or reduce the concentration of this compound, and those that involve biological processes have produced economic and environmental advantages. This study proposes a technology for biological removal of nitrate in water supply for humans, using the endocarp s coconut as a carbon source and bacteria support. The experiments were performed in pilot scale anoxic, testing different areas of the substrate surface. Results showed high rates nitrate removal during the monitoring period, noting the occurrence of denitrification after the beginning of system operation. The best performance was achieved in the treatment system containing substrate surface area increased, indicating that the decrease in the endocarp size contributed to increased bacterial activity, improving the ability to remove nitrate. About the quality analyzed aspects of water, it was found that the proposed technology has the potential water use for human consumption

Remoção de matéria orgânica em sistemas de lagoas de estabilização no Nordeste brasileiro

Stabilization pond is the main technology used for treatment wastewater, in northeast Brazil, due to lower cost of deployment, operation and maintenance compared to other technologies. Most systems of stabilization ponds has been in operation for some time, on average 10 years of operation, receiving high organic loads and do not have good removal efficiencies of the main parameters for which have been designed. Therefore it is necessary to work to quantify the efficiency of current systems. This study evaluated the biodegradability of organic matter in raw sewage, the removal of organic matter in reactors and determination of the kinetic constant removal of organic matter (k), both in reactors and in raw sewage, based on the analysis made in the laboratory and through mathematical methods proposed in the literature, in nine systems stabilization ponds, located in Rio Grande do Norte. In relation the degradation kinetics in stabilization ponds, it was observed that many papers published in the literature were obtained in pilot-scale systems, which often, due to the action of external factors such as wind and temperature, these can t be considered as a reference in the analysis of the kinetic constant K, so the need for more research into systems of scale. This study had three distinct phases and simultaneous, routine monitoring, study of the daily cycle and the determination of kinetic constant of degradation of organic matter (K). The monitoring showed that the removal efficiencies of organic matter on most systems were lower than suggested by the literature, the best efficiencies of around 76% (BOD) and 72% (COD) and the worst of the order of 48% (BOD) and 55% (COD). The calculation of K in raw sewage (Ke) was within the range of variation expected in the literature (0.35 to 0.60 days-1). Already for the results obtained for K in the reactors (Kr), there were well below the values recommended in the literature (0.25 to 0.40 d-1 for complete mix and from 0.13 to 0.17 d-1 for flow dispersed), in line with the overloads that organic systems are subject

Optimization of acid hydrolysis from the hemicellulosic fraction of Eucalyptus grandis residue using response surface methodology

Biotechnological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide fraction into monomeric sugars. Hydrolysis can be performed enzymatically and with dilute or concentrate mineral acids. The present study used dilute sulfuric acid as a catalyst for hydrolysis of Eucalyptus grandis residue. The purpose of this paper was to optimize the hydrolysis process in a 1.41 pilot-scale reactor and investigate the effects of the acid concentration, temperature and residue/acid solution ratio on the hemicellulose removal and consequently on the production of sugars (xylose, glucose and arabinose) as well as on the formation of by-products (furfural, 5-hydroxymethylfurfural and acetic acid). This study was based on a model composition corresponding to a 2 3 orthogonal factorial design and employed the response surface methodology (RSM) to optimize the hydrolysis conditions, aiming to attain maximum xylose extraction from hemicellulose of residue. The considered optimum conditions were: H2SO4 concentration of 0.65%, temperature of 157 degrees C and residue/acid solution ratio of 1/8.6 with a reaction time of 20 min. Under these conditions, 79.6% of the total xylose was removed and the hydrolysate contained 1.65 g/l glucose, 13.65 g/l xylose, 1.55 g/l arabinose, 3.10 g/l acetic acid, 1.23 g/l furfural and 0.20 g/l 5-hydroxymethylfurfural. (c) 2006 Published by Elsevier Ltd.

Avaliação da floco-decantação de manta de lodo associada à decantação de alta taxa no tratamento de águas de consumo humano

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

Pregnancy outcomes in women with repeated implantation failures after intracytoplasmic morphologically selected sperm injection (IMSI)

Background: The purpose of this study was to compare laboratory and clinical outcomes of intracytoplasmic morphologically selected sperm injection (IMSI) and conventional intracytoplasmic sperm injection (ICSI) in couples with repeated implantation failures.Methods: A total of 200 couples with at least two prior unsuccessful ICSI cycles were enrolled: 100 couples were submitted to IMSI and 100 were submitted to routine ICSI. For IMSI, spermatozoa were selected at 8400x magnification using an inverted microscope equipped with Nomarski (differential interference contrast) optics. For conventional ICSI, spermatozoa were selected at 400x magnification. Clinical outcomes were evaluated between the two groups.Results: Study patients were comparable in age, number of treatment failures, aetiology of infertility, percentage of normal form assessed by MSOME (motile sperm organelle morphology examination), semen parameters, total number of oocytes collected, number of mature oocytes collected, total number of embryos transferred and number of high-quality embryos transferred. No statistically significant differences between the two groups were observed with regard to rates of fertilisation, implantation and pregnancy/cycle. Although not statistically significant, rates of miscarriage (IMSI:15.3% vs ICSI:31.7%), ongoing pregnancy (IMSI:22% vs ICSI:13%) and live births (IMSI:21% vs ICSI:12%) showed a trend towards better outcomes in the IMSI group. In addition, analysis of subpopulations with or without male factor showed similar results.Conclusions: Our results suggest that IMSI does not provide a significant improvement in clinical outcome compared to ICSI, at least in couples with repeated implantation failures after conventional ICSI. However, it should be noted that there were clear trends for lower miscarriage rates (approximate to 50% reduced) and higher rates of ongoing pregnancy and live births (both nearly doubled) within the IMSI group. Further confirmation as well as randomized large-scale trials are needed to confirm the beneficial effects of IMSI in couples with poor reproductive prognoses.

Ultrasound efficiency in relation to sodium hypochlorite and filtration adsorption in microbial elimination in a water treatment plant

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desempenho de clones de seringueira da série IAC 300 na região do planalto de São Paulo

O objetivo deste trabalho foi selecionar clones de seringueira (Hevea spp.) promissores para a região do planalto do Estado de São Paulo. de uma população de 70 clones, de polinização controlada, integrantes do experimento de avaliação em pequena escala, foram avaliados 16 da série IAC 300. O experimento foi instalado na Estação Experimental de Pindorama, no espaçamento de 7 x 3 m, em delineamento de blocos casualizados, com três repetições, tendo os clones RRIM 600 e GT 1 como testemunhas. Quanto à produção de borracha seca, destacaram-se oito e dez clones superiores ao RRIM 600 e GT 1, respectivamente. Todos os clones avaliados apresentaram-se vigorosos em relação ao perímetro do caule na abertura do painel. Sete deles mostraram alta resistência; sete, resistência moderada, e dois, suscetíveis à antracnose do painel. Sugere-se sua avaliação em experimentos de grande escala, para avaliar, além da produção, os demais caracteres secundários, em diferentes ambientes, para futuras recomendações em larga escala para o Estado de São Paulo.

Desempenho de reatores anaeróbios de fluxo ascendente com manta de lodo em dois estágios tratando águas residuárias de suinocultura

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

Desempenho de processo anaeróbio em dois estágios (reator compartimentado seguido de reator UASB) para tratamento de águas residuárias de suinocultura

Avaliou-se o efeito das águas residuárias de suinocultura com concentrações de sólidos suspensos totais em torno de 6.000 mg L-1 (DQOtotal variando de 7.557 a 11.640 mg L-1) no desempenho de processo anaeróbio em dois estágios compostos por reator compartimentado (ABR) e reator de fluxo ascendente com manta de lodo (UASB), instalados em série, em escala-piloto (volumes de 530 e 120 L, respectivamente), submetidos a tempos de detenção hidráulica (TDH) de 56 a 18 h no primeiro reator e de 13 a 4 h no segundo reator. As eficiências médias de remoção de DQOtotal variaram de 71,1 a 87,5% no reator ABR e de 41,5 a 50,1% no reator UASB, resultando em valores médios de 86,8 a 94,9% para o sistema de tratamento anaeróbio em dois estágios com carga orgânica volumétrica (COV), na faixa de 5,05 a 10,12 kg DQOtotal (m³ d)-1, no reator ABR, e de 2,83 a 9,63 kg DQOtotal (m³ d)-1, no reator UASB. As eficiências de remoção de SST e SSV foram da ordem de 95,6%. O teor de metano no biogás manteve-se acima de 70% para os dois reatores. A produção volumétrica de metano máxima de 0,755 m³ CH4 (m³ d)-1 ocorreu no reator 1, com COV de 10,12 kg DQOtotal (m³ d)-1 e TDH de 18 h. Os valores médios de pH variaram na faixa de 7,2 a 8,0 para os efluentes dos reatores 1 e 2. Os ácidos voláteis totais mantiveram-se estáveis com concentrações abaixo de 200 mg L-1. Com variações abruptas e acentuadas de concentrações de SST e DQOtotal do afluente, os reatores mantiveram as eficiências de remoção de DQO e sólidos suspensos, em torno de 70%, e a qualidade do biogás, com 80% de CH4.

Reatores anaeróbios operados em batelada sequencial, seguidos de lagoas de polimento, para o tratamento de águas residuárias de suinocultura. Parte I: produção de metano e remoção de DQO e de sólidos suspensos

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

Reatores anaeróbios operados em batelada sequencial seguidos de lagoas de polimento para o tratamento de águas residuárias de suinocultura. Parte II: remoção de nutrientes e coliformes

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

Performance of UASB reactors in two stages under different HRT and OLR treating residual waters of swine farming

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

Tratamento de águas residuárias de suinocultura em reator anaeróbio operado em batelada sequencial

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

Degradation of Acid Blue 40 dye solution and dye house wastewater from textile industry by photo-assisted electrochemical process

In this paper, electrochemical and photo-assisted electrochemical processes are used for color, total organic carbon (TOC) and chemical oxygen demand (COD) degradation of one of the most abundant and strongly colored industrial wastewaters, which results from the dyeing of fibers and fabrics in the textile industry. The experiments were carried out in an 18L pilot-scale tubular low reactor with 70% TiO2/30% RuO2 DSA. A synthetic acid blue 40 solution and real dye house wastewater, containing the same dye, were used for the experiments. By using current density of 80 mA cm(-2) electrochemical process has the capability to remove 80% of color, 46% of TOC and 69% of COD. When used the photochemical process with 4.6 mW cm(-2) of 254nm UV-C radiation to assist the electrolysis, has been obtained 90% of color, 64% of TOC and 60% of COD removal in 90 minutes of processing; furthermore, 70% of initial color was degraded within the first 15 minutes. Experimental runs using dye house wastewater resulted in 78% of color, 26% of TOC and 49% of COD in electrolysis at 80 mA cm(-2) and 90 min; additionally, when photo-assisted, electrolysis resulted in removals of 85% of color, 42% of TOC and 58% of COD. For the operational conditions used in this study, color, TOC and COD showed pseudo-first-order decaying profiles. Apparent rate constants for degradation of TOC and COD were improved by one order of magnitude when the photo-electrochemical process was used.

Behaviour of biofuel addition on metallurgical properties of sinter

Blast furnace gas yield is essentially controlled by a gas-solid reaction phenomenon, which strongly influences hot metal manufacturing costs. As a result of rising prices for reducing agents on the international market, Companhia Siderurgica Nacional decided to inject natural gas into its blast furnaces. With more gas inside the furnace, the burden permeability became even more critical. To improve blast furnace gas yield, a new technological approach was adopted; raising the metallic burden reaction surface. To that end, a special sinter was developed with permeability being controlled by adding micropore nucleus forming agents, cellulignin coal, without, however, degrading its mechanical properties. This paper shows the main process parameters and the results from physicochemical characterisation of a sinter with controlled permeability, on a pilot scale, compared to those of conventional sinter. Gas flow laboratory simulations have conclusively corroborated the positive effects of micropore nucleus forming agents on enhancing sinter permeability.