Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Artigo | IMSEAR | ID: sea-219393

RESUMO

Background and Objective: The majority of liquid waste generated by the tofu industry in Semarang exceeds the recommended limit. This condition disturbs the ecology of the surrounding environment. so a solution is needed to manage it. The use of bacteria in bioremediation technology has been proven to reduce pollutants produced by the tofu industry. The purpose of this study was to identify specific bacteria and test their ability to bioremediate pollutants from tofu wastewater using the Chemical Oxygen Demand (COD) parameter. Methodology: Methodology: The study was exploratory and experimental in nature, with the variable ability of degradative bacteria degrading tofu industrial wastewater based on COD parameters. Bacterial identification was performed using the 16S-rRNA Gene Analysis method, genomic DNA extraction with the Quick-DNA Bacterial Miniprep Kit, PCR amplification, and bi-directional sequencing. Results: The results of the identification of the selected bacteria show that they are molecules of the type nucleic acid with a query length of 1394. with a lineage report and a 93% phylogenetic tree as Bacillus subtilis, Bioremediation test shows that tofu waste can be degraded. The degradation percentage is 17%. Conclusion: Bacillus subtillis, a bacterium that degrades tofu industrial wastewater, was found as an indigenous bacteria.

2.
Rev. colomb. quím. (Bogotá) ; 48(3): 26-35, sep.-dic. 2019. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1058425

RESUMO

Abstract Every year the demand for energy worldwide is increasing. There are some alternatives to reduce these problems, such as clean energy or renewable energy. A particular alternative is the microbial fuel cells. These cells are biochemical reactors that convert chemical energy into electricity. The present research evaluated the dairy serum to produce bioelectricity from micro fuel cells (MFC) that were constructed with low-cost materials and with isolated bacteria in anaerobic sediments, located in Ecuadorian national territory, producing maximum voltages of 0.830 V in the circuit and a maximum power density of 30 mW / m2. This low voltage was worked with 50 mL MFCs and with an output voltage of 300 mV. Under these conditions, a FLYBACK lift circuit isolated by the transformer was designed. This new circuit could increase the voltage from 30 mV to enough voltage to light a 2.5 V LED. Therefore, the energy produced by the MFC can be directly used to light a LED and to charge capacitors. This study shows that these MFCs, together with the designed circuit, could be used potentially to generate clean energy.


Resumen Cada año la demanda de energía, en todo el mundo, va en aumento. Existen algunas alternativas para reducir estos problemas, tales como las energías limpias y renovables. Una alternativa muy específica es el uso de celdas de combustible microbianas. Dichas celdas son reactores bioquímicos que convierten la energía química en electricidad. La presente investigación evaluó el suero lácteo para la producción de bioelectricidad en celdas de combustible microbianas (MFC). Estas fueron construidas con materiales de bajo costo y con bacterias aisladas en sedimentos anaeróbicos, ubicados en territorio nacional ecuatoriano, produciendo voltajes máximos de 0,830 V en el circuito y una densidad de potencia máxima de 30 mW / m2. Este bajo voltaje se trabajó con MFC de 50 mL y con un voltaje de salida de 300 mV. Bajo estas condiciones, se diseñó un circuito de elevación FLYBACK aislado por transformador. Este nuevo circuito aumentará el voltaje de 30 mV a un voltaje suficiente para encender un LED de 2.5 V. Por lo tanto, la energía producida por las MFC puede ser directamente utilizable para encender un LED y cargar los condensadores. Este estudio muestra que dichas celdas MFC, junto con el circuito diseñado, podrían utilizarse, potencialmente, para generar energía limpia.


Resumo Todos os anos a demanda por energia, em todo o mundo, está aumentando. Existem algumas alternativas para reduzir esses problemas, como energias limpas e renováveis. Uma alternativa muito específica é o uso de células combustíveis microbianas. Essas células são reatores bioquímicos que convertem energia química em eletricidade. O presente trabalho avaliou o soro lácteo para a produção de bioeletricidade em células a combustível microbianas (CCM), Estes foram construídos com materiais de baixo custo e bactérias isoladas em sedimentos anaeróbios, localizados no território nacional equatoriano, produzindo tensões máximas de 0,830 V no circuito e uma densidade de potência máxima de 30 mW / m2. Esta baixa voltagem trabalhamos com CCM de 50 mL e com uma voltagem de saída de 300 mV. Sob essas condições, um circuito de elevação FLYBACK isolado por transformador foi projetado. Este novo circuito aumentará a tensão de 30 mV para uma tensão suficiente para ligar um LED de 2,5 V. Portanto, a energia produzida pelo MFC pode ser diretamente utilizável para ligar um LED e carregar os capacitores. Este estudo mostra que essas células CCM, juntamente com o circuito projetado, poderiam ser usadas para gerar energia limpa.

3.
Electron. j. biotechnol ; 39: 98-106, may. 2019. tab, graf, ilus
Artigo em Inglês | LILACS | ID: biblio-1052269

RESUMO

BACKGROUND: The amount of municipal solid waste (MSW) gradually increased along with the rapid development of modern cities. A large amount of landfill leachate are generated with excessive chemical oxygen demand (COD), which create a great deal of pressure on the environment-friendly treatment process. Anaerobic digestion is an ideal technique to solve the above problem. RESULTS: A thermophilic granular sludge was successfully adapted for anaerobic digestion of MSW leachate (from an aging large-scale landfill) for methane production. The COD degradation efficiency improved by 81.8%, while the methane production rate reached 117.3 mL CH4/(g VS d), which was 2.34-fold more than the control condition. The bacterial and archaeal communities involved in the process were revealed by 16S rRNA gene high-throughput pyrosequencing. The richness of the bacterial community decreased in the process of thermophilic granular sludge, while the archaeal community structure presented a reverse phenomenon. The bacterial genus, Methanosaeta was the most abundant during the mesophilic process, while Methanobacterium, Methanoculleus, Methanosaeta and Methanosarcina were more evenly distributed. The more balanced community distribution between hydrogenotrophic and acetotrophic methanogens implied a closer interaction between the microbes, which further contributed to higher methane productivity. The detailed relationship between the key functional communities and anaerobic digestion performances were demonstrated via the multivariate canonical correspondence analysis. Conclusions: With the assistance of adaptive thermophilic granular sludge, microbial community structure was more evenly distributed, while both of COD degradation rate and methane production was improved during anaerobic digestion of MSW landfill leachate.


Assuntos
Bactérias Anaeróbias/metabolismo , Resíduos Sólidos , Digestão Anaeróbia , Tratamento de Lodos , Metano/metabolismo , Esgotos/microbiologia , Bactérias Anaeróbias/isolamento & purificação , Poluentes Químicos da Água , Reação em Cadeia da Polimerase , Área Urbana , Biocombustíveis , Análise da Demanda Biológica de Oxigênio , Temperatura Alta , Anaerobiose
4.
Chinese Journal of Medical Aesthetics and Cosmetology ; (6): 330-334, 2019.
Artigo em Chinês | WPRIM | ID: wpr-756581

RESUMO

Objective To investigate the wound-healing process in a rat model of skin full-thickness incisions and to detect related possible mechanism.Methods Twenty-four female rats were selected and the dorsal skin of rats was used as the experimental area.A cutaneous excision (6 mm diameter) was made on the back of each animal,close to the cervical area.The dorsal skin of every rat was allocated to three groups which were treated with physiological saline,human recombinant epidermal growth factor (rhEGF),and CDPs,respectively.After making a rat model of skin incisions,we observed the wound healing process,took photos of the wounds under a digital microscope,and use sulfuric graph paper to record the size of every wound.At the 3rd,6th,9th,12th day after modeling,6 rats were killed,and mRNA expression of K10,K14,and EGF was detected in the skin tissues using a RT-PCR technique.Results At the 6th and 12th day after modeling,there were significant differences between the experimental group and the blank control group (P<0.05).The gene expression of EGF,K-14 in the third day and that of EGF,K-10 and K-14 in the 6th and 12th day were upregulated compared with control group,and there were significant differences between them (P < 0.05).Conclusions CDPs have a beneficial effect on the acceleration of skin wound healing,possibly due to increasing keratinocyte proliferation and up-regulating the expression of K10,K14 and EGF genes.

5.
Artigo | IMSEAR | ID: sea-189563

RESUMO

The Norwegian Food Safety Authority (Mattilsynet) asked the Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet) to assess if the criteria for safe use of plant ingredients in diets for aquacultured fish fulfil the Feed regulative §7 to “not induce negative health effects in the animal”, and in this context aquacultured fish. The use of feed ingredients of both plant and animal origin is set by the regulation “Forskrift 7. November 2002 nr 1290”, and amendments. The objective of the regulation is to protect animals, consumers and the environment. For animals, the feed shall not pose a risk, or danger, to their health. Aspects to be assessed were whether the changes in fish diet ingredient composition seen in recent years with high levels of plant ingredients, plus additions of immunostimulants, would in any manner challenge fish health and if any ingredient should be limited due to its negative effect, or induce any long-term negative effect. “Long-term” here extends beyond normal production time for consumption, e.g. when substances that might affect fish health are included in broodstock diets. Atlantic salmon (Salmo salar), rainbow trout (Onchorhyncus mykiss), Atlantic halibut (Hippoglossus hippoglossus) and Atlantic cod (Gadus morhua) should especially be addressed. However, since all life stages should be included, especially broodstock, and also possible long-term effects, and literature on these for the requested species is scarce, the assessment mentions studies on other species when relevant. With the exception of full-fat and extracted soybean meal for salmonids, substituting at least part of the fishmeal fraction of aquafeeds with individual plant ingredients is promising, at least in the short to medium term. Indeed in some cases, diets containing up to 20% inclusion level of high-quality plant protein sources have resulted in better nutrient digestibility and growth parameters than the fishmeal-based control diets. When substituting fishmeal with plant ingredients, however, it is necessary to balance the diets regarding limiting amino acids and minerals. Adding plant proteins to fish diets result in the introduction of anti-nutritional factors. There is an urgent need to investigate consequences of various anti-nutritional factors, individually and in combinations, to nutrient digestibility, utilization and metabolism as well as to intestinal function, structure, defence mechanisms and microbiota. Long-term effects also merit investigation. This will aid in the ability to predict how a newly introduced plant ingredient as well as combinations of plant ingredients may affect the fish and identify steps needed to avoid adverse health effects. As many of the potential disadvantages of using plant oils in salmonid diets are related to either very high levels of n-6 PUFA (most available oils) or very high levels of linseed oil, it would be recommended that mixtures of plant oils should be used as feed inclusions. By adjusting the ratio of n-6 and n-3 the level of eicosanoids can be controlled. By including palm oil, potential problems in lipid digestibility and transport can be controlled. A standard inclusion of soybean lecithin may also be advisory. These and other variants of mixtures of oil sources have been explored in recent years with some success in salmonid fish. Such mixtures do not seem to be necessary for marine fish. Modern finfish aquaculture faces problems such as bone and skeletal deformities, cataracts, heart disorders, unspecific ulceration and various digestive disorders including intestinal colic in Atlantic cod, gastric dilatation (bloat) in rainbow trout, and intestinal tumours, at low incidence, in Atlantic salmon broodstock. Most of the mentioned problems have been related to malnutrition, feed, intensive growth and/or unfavourable environmental conditions. The disorders are often not lethal, but may imply a fish welfare problem and increase the susceptibility to secondary disorders and infectious diseases. Major changes in feed composition and feed ingredients may increase the risk for such production-related disorders in intensive fish farming. Care should be taken when choosing plant alternatives, both types and qualities, to prevent nutrition-related diseases such as skeletal deformities, cataracts, heart conditions, and other, unspecific symptoms. The change from marine- to plant-based diet ingredients, results in changed profile and content of undesirable substances. The list of undesirable substances included in the feed legislation is, in general, sufficient, but it should be considered to include pesticides in use today and more of the mycotoxins. Currently only aflatoxin B1 is included, while only recommendations exist for other mycotoxins. Studies of dietary exposure to undesirable substances, e.g. pesticides and mycotoxins, and their toxic effects and toxicokinetics in fish are scarce. To date, the application of pre- and probiotics for the improvement of aquatic environmental quality and for disease control in aquaculture seems promising; however, the information is limited and sometimes contradictory. Currently there are numerous gaps in existing knowledge about exogenous nucleotide application to fish including various aspects of digestion, absorption, metabolism, and influences on various physiological responses, especially expression of immunogenes and modulation of immunoglobulin production. As limited information is available about the effect of immunostimulants, prebiotics and nucleotides on gut morphology, this topic should be given high priority in future studies. Heat processing of raw materials and of the complete fish diets may potentially alter nutritional properties of plant materials. However, the negative effects appear to be modest under practical conditions.

6.
Rev. colomb. biotecnol ; 19(2): 95-104, jul.-dic. 2017. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-900441

RESUMO

RESUMEN El impacto ambiental generado por las aguas residuales de la explotación de carbón es significativo por la carga contaminante que estas por lo general poseen, representada en grandes concentraciones de sólidos suspendidos, metales (principalmente hierro) y otros elementos traza, además del bajo pH que suelen tener. El objetivo del presente trabajo fue evaluar la eficiencia de un sistema de tratamiento biológico a partir de microalgas de la división Chlorophyta para remover la carga contaminante de las aguas residuales de una mina de la empresa Coal North Energy S.A.S. Al final del tratamiento se obtuvieron porcentajes de remoción del 66,67% para hierro total, 46,67% para cloruros y 95,1% para DQO (Demanda Química de Oxígeno).


ABSTRACT The environmental impact caused by coal mining wastewater is significant due to the pollution load, usually represented in high concentrations of suspended solids, metals (mainly iron) and other trace elements and low pH values. The aim of this study was to evaluate the efficiency of a biological treatment system using microalgae belonging to the Chlorophyta division, for the removal of contaminants from the wastewater from a mine owned by Coal North Energy S.A.S. At the end of treatment, it was possible to remove up to 66.67% of total iron, 46.67% for chloride and 95.1% for Chemical Oxigen Demand.

7.
Eng. sanit. ambient ; 22(2): 381-390, mar.-abr. 2017. tab, graf
Artigo em Português | LILACS | ID: biblio-840401

RESUMO

RESUMO O tratamento anaeróbio de efluentes industriais ricos em sulfato e sódio pode ser limitado por vários fatores, dentre os quais a relação DQO/sulfato, a concentração de SO4 2- e a concentração de sódio. Entre os fenômenos investigados estão a competição entre bactérias redutoras de sulfato e arquéias metanogênicas por substrato, a concentração de sulfeto gerado na sulfetogênese e a inibição por cátions. Este trabalho apresentou e discutiu os resultados da operação de um reator UASB, com volume útil de 10,5 L e vazão de 16,0 L.dia-1. Utilizou-se glicose, acetato e metanol (DQO≈2.000 mg.L-1), sob razão DQO/sulfato variando de 0,20 a 6,15, concentração de sulfato de 0,3 a 10,0 g.L-1 e concentração do cátion Na+ de 0,70 g.L-1 a 5,40 g.L-1. A eficiência de remoção de DQO foi mantida acima de 80%, e a concentração de sulfato removida ficou limitada a cerca de 800 mg.L-1 durante o período experimental. A atividade metanogênica específica do lodo (AME) foi de 0,630 gCH4-DQO.gSSV-1 até carga de sulfato de 0,300 gSO4 2-.L-1 e (razão DQO/sulfato de 6,15), declinando até atingir 0,168 gCH4-DQO.gSSV-1 (queda de 70%) na última fase com 10,000 gSO4 2-.L-1 (razão DQO/[SO4 2-] de 0,24) e concentração de Na+ de 5,41±0,10 g.L-1. O aumento crescente das concentrações de sódio e sulfato, mantendo-se a concentração de matéria orgânica constante, permitiu constatar a inibição da metanogênese por sódio e sulfeto, mesmo em concentrações abaixo das consideradas inibidoras individualmente. O efeito do sódio na estrutura do grânulo foi determinante na inibição da metanogênese observada.


ABSTRACT The anaerobic treatment of industrial wastewater presenting high concentrations of sulfate and sodium may be limited by several factors, including the ratio COD / [SO4 2-], the concentration of SO4 2- and the concentration of Na+. The competition between sulfate reducing bacteria and methanogenic archaea for substrate, the concentration of sulfide generated in sulfidogenesis, and the inhibition by cations are among the main phenomena that have been investigated. This paper presented and discussed the results of a UASB reactor with a volume of 10.5 L and flowrate of 16.0 L.day-1, subjected to increasing COD/sulfate ratio whereas influent COD was kept constant. Glucose, acetate and methanol (≈2,000 COD mg.L-1) were the carbon sources, and the COD/sulfate ratio ranged from 0.20 to 6.15 for sulfate concentrations of 0.3 to 10.0 g.L-1, Na + concentrations of 0.70 g.L-1 to 5.40 g.L-1. The COD removal efficiency was maintained above 80%, and the sulfate removal was limited to 800 mg.L-1 throughout the experimental period. The specific methanogenic activity (SMA) was 0.630 gCH4-DQO.gSSV-1 for 0.300 gSO4 2-.L-1 (COD/sulfate of 6.15), decreasing to 0.168 (70% decrease) in the last phase (COD /sulfate of 0.24) at concentrations of 10.000 gSO4 2-.L-1 and of Na+ 5.41±0.10 g.L-1. The progressive increase of sulfate and sodium concentrations at constant influent COD resulted in methanogenesis inhibition by sodium and sulfide, even at concentrations bellow the inhibition limits, if individually considered. The effect of sodium in the granule structure was determinant for methanogenesis inhibition.

8.
Eng. sanit. ambient ; 22(1): 179-186, jan.-fev. 2017. tab, graf
Artigo em Português | LILACS | ID: biblio-840387

RESUMO

RESUMO No Brasil, cerca de 32.700 postos de lavagem de veículos consomem 3,7 milhões de m3/mês-1, média de 60 L por veículo. Esse consumo poderia ser minimizado, se o efluente fosse devidamente tratado e reutilizado. Como diversos tipos de efluentes têm sido eficientemente tratados por técnicas eletroquímicas, como a eletrocoagulação (EC) e a eletroflotação (EF), o objetivo principal deste estudo foi desenvolver um sistema de tratamento de efluentes de lavagem de carros por EC, usando eletrodos de alumínio. Parâmetros como pH inicial, corrente elétrica aplicada e tempo de eletrólise foram otimizados por meio de análises físico-químicas e estatísticas. Em sua condição ótima, pH 5, corrente elétrica de 3,5 A e tempo de 20 minutos, o sistema conseguiu reduzir em 73% a demanda química de oxigênio (DQO), 58% de surfactantes e no mínimo 90% a turbidez e os sólidos suspensos totais (SST). Além da simples implantação e operação, a técnica mostrou-se eficiente na recuperação desse tipo de efluente, podendo ser utilizada em sistemas de reúso de água de lavagem de veículos.


ABSTRACT In Brazil, about 32,700 vehicle washing stations consume 3,7 million m3 per month-1, average of 60 L per vehicle. Consumption could be minimized if the effluent was properly treated and reused. As different types of effluents have been effectively treated by electrochemical techniques, such as electrocoagulation (EC) and electrocoagulation (EF), the main objective of this study was to develop a treatment system of carwash wastewater, by EC using electrodes aluminum. Parameters like the initial pH, applied electric current and electrolysis time were optimized by means of physical-chemical analysis and statistics. In its optimum condition, pH 5, electrical current of 3,5 A and time of 20 minutes, the system has managed to reduce by 73% the chemical oxygen demand (COD), 58% of surfactants and a minimum of 90% turbidity and total suspended solids (TSS). Besides the simple installation and operation, the technique was efficient in the recovery of this type of effluent and can be used in reuse system carwash water.

9.
Braz. j. microbiol ; 47(2): 279-286, Apr.-June 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-780848

RESUMO

Abstract Organic decomposition is a complex interaction between chemical, physical and biological processes, where the variety of aquatic vascular plants is essential for the trophic dynamics of freshwater ecosystems. The goal of this study was to determine the aquatic macrophyte Eichhornia azurea (Sw.) Kunth decomposition rate, the time relation with the limnological parameters, and whether this relationship is a result of decomposition processes. To that end, we collected water and leaves of E. azurea in Surf Leopoldo, PR. The experiment consisted of two treatments: 25 containers with 450 mL of water and 0.8 g of biomass dry weight were used with or without the addition of macrophytes. Samples were collected in triplicate at times 0, 3 h, 6 h, 12 h, 24 h, 72 h, 120 h, 168 h and 240 h. When the container was removed, the plant material was dried in an oven. After 48 h, the material was measured to obtain the final dry weight. Analyses of pH, conductivity, dissolved oxygen, total phosphorus N-ammonia (NH4), soluble reactive phosphorus (PO4) and dissolved organic carbon were performed, and the decomposition rate was calculated. The results showed significant temporal variation of limnological parameters in the study. Additionally, dissolved oxygen, conductivity, dissolved organic carbon and total phosphorus were correlated with the dry weight of the biomass, suggesting that E. azurea decomposition significantly interferes with the dynamics of these variables.


Assuntos
Bactérias/metabolismo , Eichhornia/microbiologia , Bactérias/crescimento & desenvolvimento , Biodegradação Ambiental , Cinética , Ecossistema , Eichhornia/química
10.
Rev. colomb. biotecnol ; 17(2): 55-64, jul.-dic. 2015. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-769082

RESUMO

En esta investigación se utilizó el colorante azul directo brl para remoción anaerobia con un consorcio bacteriano aislado de efluentes industriales del Parque Industrial río Seco (PIRS), Arequipa, Perú; en un reactor anaerobio de flujo ascendente UASB con carbón activado. El reactor tuvo una capacidad de 14.4 L con lodos y carbón activado del 40% de volumen, con una carga orgánica de 6 Kg DQO/m³•día y un tiempo de retención hidráulica de 1 día con un flujo ascendente. El objetivo fue medir la eficiencia de la remoción anaerobia del colorante en un tiempo de 28 días. Los resultados demostraron un incremento del 41% de los Sólidos Suspendidos Volátiles (SSV) de 12894 mg•L-1 a 21546 mg•L-1 bajo las condiciones del experimento, con una remoción del 57% de la Demanda Química de Oxigeno (DQO) de 484 mg•L-1 a 122 mg•L-1 y una remoción del 87% del colorante azul directo brl de 69.61 mg•L-1 a 9 mg•L-1. Los resultados con el carbón activado granular solamente, demostraron una remoción del 61% del colorante azul directo brl de 70.67 mg•L-1 a 27.83 mg•L-1 a los 28 días.


In this research the brl direct blue dye was used for anaerobic removal with a bacterial consortium of industrial effluents from Industrial Park Río Seco (IPRS), Arequipa, Peru; in an anaerobic reactor of UASB Upflow with activated carbon. The reactor had a capacity of 14.4 L with sludge and activated carbon of 40% of volume, with an organic load of 6 Kg COD/m³•dia and a hydraulic retention time of 1 day with an upward flow. The objective was to measure the efficiency of the anaerobic removal of coloring in a time of 28 days. The results showed an increase of 41% of the solids suspended volatile (SSV) 12894 mg•L-1 up to 21546 mg•L-1 under the conditions of the experiment, with a removal of 57% of the chemical demand of oxygen (COD) from 484 mg•L-1 to 122 mg•L-1 and a removal of 87% of the dye Blue direct the 69.61 brl mg•L-1 to 9 mg•L-1. Results with activated charcoal granular only, they showed a removal of 61% of the dye Blue direct 70.67 brl mg•L-1 to 27.83 mg•L-1 at 28 days.

11.
Eng. sanit. ambient ; 20(2): 191-198, abr.-jun. 2015. tab, ilus
Artigo em Português | LILACS | ID: lil-759302

RESUMO

Um dos problemas comumente encontrado na análise estatística de dados provenientes do monitoramento da qualidade da água envolve os chamados dados censurados. Este estudo mostra como os valores calculados das concentração médias de amostras que contenham dados censurados são influenciadas pelo tamanho da amostra, percentual de dados censurados e método de cálculo. As concentrações médias foram calculadas com os métodos de substituição e maximum likelihood estimator (MLE) para amostras de demanda química de oxigênio e fosfato. O intervalo de confiança da média foi utilizado como métrica de comparação. Os resultados revelam que as concentrações médias calculadas com o método de substituição simples se posiciona fora do intervalo de confiança. Já o método MLE calcula valores aceitáveis, porém, a eficácia do método depende de um limite de elasticidade do nível de censura e do tamanho da amostra.


One of the most common problems in statistical analysis of data from water quality monitoring programs involves the so-called censored data. This study highlights how the sample mean concentration of chemical oxygen demand and phosphate variables are influenced by the estimation method, sample size and percentage of censored data. The confidence interval was used as a metric for comparison of calculated sample mean concentrations on both simple substitution and maximum likelihood estimator (MLE) methods. The results show that sample mean concentrations calculated by simple substitution method are positioned outside the confidence interval. Otherwise, the MLE method produces acceptable values for sample mean concentration, although the magnitude is constrained by sample size and percentage of censored data. The effectiveness of the method depends on an elastic limit of censoring level and sample size.

12.
Artigo em Inglês | IMSEAR | ID: sea-163278

RESUMO

Aims: The aim of this study was to investigate the biodegradation capacity of selected indigenous fungal isolates and optimization of their degradation ability using various environmental factors such as pH, incubation temperature, nutrient concentration and inoculums size in reducing pollution effect of palm oil mill effluent (POME) in the environment. Place and Duration of Study: Two fungal isolates Candida rugosa and Geotrichum candidum used in this work were previously isolated from POME sample collected from Starline palm oil mill industries, Umukalika, Obingwa LGA, Abia state Nigeria in previous work of authors. The study was carried out from March to August, 2013. Methodology: Spore suspension was prepared by adding 10 ml of 0.1% Tween 80 onto PDA slant of 5 days old culture of Candida rugosa and Geotrichum candidum respectively. Biodegradation of POME was carried out by inoculating 0.1ml (106spores/ml) of respective fungal isolates into different 500 ml Erlenmeyer flasks containing 100ml each of raw POME. They were incubated at 30ºC on a rotary shaker (200rpm). Samples were taken every 24hrs for 144hrs to determine BOD, COD, oil & grease. Similarly, optimization of biodegradation was carried out by studying the effect of different environmental conditions such as different initial pH levels (4.0-8.0), incubation temperature (25-50ºC), concentrations of soy bean (1.5-4.5% w/v) and inoculum size (0.1-0.5 v/v). The experiments were done in triplicates. Results: Biodegradation studies with selected indigenous fungi showed that C. rugosa was able to remove (44.6%) BOD, (13.9%) COD , (50.7%) oil and grease (O&G) while G. candidum reduced BOD, COD, O&G by 46.9%,16.9% and 64,9% respectively after 144hrs. Optimization of degradation in POME using various environmental and nutrients conditions revealed that at pH 8, C. rugosa showed best degradation of COD (48.6%), BOD (74.5%), O&G (41.8%) removal while COD (59.1%), BOD (75.7%) , O&G (59.1%) removal was observed with G. candidum treatment. The optimal incubation temperature for degradation using each of fugal isolates was at 35ºC with 85.2% BOD , 71.8% COD and 67.3% O&G removal for C. rugosa , 87.3% BOD and 63.4% COD for G. candidum .The best degradation ability for C. rugosa and G. candidum were demonstrated at 3.5w/v and 2.5w/v soybean concentrations respectively. The result also showed that increase in inoculum size could not completely reduce oil and grease during degradation process possibly because no single culture supports degradation optimally due to presence of complex sugars Conclusion: The selected fungal isolates exhibited high efficiency for removal of oil and grease as well as organic matter from POME but required control of environmental conditions and nutrient expansion for the effective biodegradation of POME.

13.
Br Biotechnol J ; 2014 Mar; 4(3): 317-324
Artigo em Inglês | IMSEAR | ID: sea-162439

RESUMO

Aims/objectives: The cognition about microbial population of activated sludge and their treatment potential will be very useful for industrial wastewater treatment plant operation. Methodology: In this study microbial population of activated sludge process that was used for pharmaceutical wastewater has been investigated. Sampling was done from return sludge line and after serial dilution 1500 plates were studied. Methods for separating the bacteria from wastewater was pour plate method. All bacterial samples were purified using nutrient Agar and Macconkey Agar culture. Bacteria were separated from return sludge line and classified into 3 groups after biochemical tests and morphological analysis, These include positive bacteria of Bacillus genus, Pseudomonas aeruginosa and Flavobacterium. Results: The biodegradability study on pharmaceutical effluent using identified cultures in laboratory scale showed that Bacillus spp. are the most efficient bacteria for organic matter degradation. Conclusion: Results of this study showed that providing a microbial bank of these spp. can be useful for resistant operation of activated sludge.

14.
Eng. sanit. ambient ; 18(4): 371-380, Oct-Dec/2013. tab, graf
Artigo em Português | LILACS | ID: lil-695999

RESUMO

Indústrias de laticínios contêm elevada concentração de matéria orgânica que podem causar poluição. Este trabalho propôs estudar a remoção de matéria orgânica e de nutrientes de um efluente sintético de laticínio, disposto em reatores em bateladas repetidas inoculados com Aspergillus niger AN400. O sistema foi composto por reatores com diferentes configurações e, para cada tipo de montagem, variou-se o material-suporte. O estudo foi realizado em quatro ciclos de cinco dias, com retiradas diárias de alíquotas. A análise dos resultados mostrou eficiência de remoção de demanda química de oxigênio com picos de até 71,7%, concluindo-se que a tecnologia mostrou-se viável na remoção de matéria orgânica. Em relação aos nutrientes, o sistema pôde remover satisfatoriamente nitrato; contudo, para remoção de amônia, não se apresentou promissor.


Dairy industries contain high concentration of organic matter that may cause pollution. This study proposed to study the removal of organic matter and nutrients from a synthetic dairy effluent, arranged in repeated batch reactors inoculated with Aspergillus niger AN400. The system was composed of reactors with different configurations and, for each type of assembly, the support material was varied. The study was conducted in four cycles of five days, with daily withdrawals of portions. The results showed efficiency of removal of chemical oxygen demand with peaks of up to 71.7%. One might conclude that the technology was feasible in the removal of organic matter. For nutrients, the system could successfully remove nitrate; however, for removal of ammonia, it was not promising.

15.
Artigo em Inglês | IMSEAR | ID: sea-157859

RESUMO

Vinasse that is bottom product of distillation unit from alcohol industry contains Chemical Organic Compound (COD) in high concentration. The purpose of this study was to investigate the effect of COD/N ratios of substrate and pH control to biogas production from vinasse. Study Design: This study used anaerobic digestion-laboratory scale at room temperature in batch system. Urea was added as nitrogen source to adjust COD/N ratios of 400/7, 500/7, 600/7, and 700/7. Initial pH for all variables was adjusted 7.0 by using NaOH solution. Place and Duration of Study: Waste-treatment Laboratory, Department of Chemical Engineering, University of Diponegoro, Indonesia, between August 2012 and January 2013. Methodology: Vinasse used was obtained from the alcohol industry that produced alcohol from molasses. Polyethylene bottles which had volume 5 liters were used as digester. Vinasse of 1 liter was put into digester. Urea was added to make variation of COD/N ratio. Initial pH of all variables was adjusted 7.0 by using 10 N NaOH solution. Rumen fluid (10%v/v vinasse) was added as methanogenic bacteria inoculum. Biogas formed was measured by using water displacement method every once in two days to know biogas production daily. pH of substrates in the digesters was measured by using pH meter every once in two days to know pH profile daily. COD of substrates was measured by using COD Analyzer Hanna Reactor with specification High Range of Reagent. Solution of NaOH 2 N was used to maintain pH of substrate in range neutral condition (7.0±0.2) during the fermentation process. Results: Biogas formed at COD/N ratio of control variable (1436/7); 400/7; 500/7; 600/7; 700/7 were 3.673; 4.909; 6.079; 6.096; 5.631 mL/g COD respectively. pH profiles for all variables were decreasing from beginning until ending of fermentation. With controlled pH, pH of substrates was maintained at neutral condition, so methanogenic bacteria could grow well in the digesters. Consequently biogas formed at controlled pH was larger than that at uncontrolled pH. The values of COD removal for COD/N ratio of control variable; 400/7; 500/7; 600/7; 700/7 were 1.27±0.43; 1.59±0.43; 2.85±0.39; 3.21±0.49; 2.22±0.39 % respectively at uncontrolled pH, whereas at controlled pH the values of these were 11.98±0.56; 12.82±0.56; 12.03±0.94; 13.05±0.35; 12.61±0.56 % respectively. Conclusions: COD/N ratios of 400/7, 500/7, 600/7, 700/7 produced more total biogas than control variable. Variable of COD/N of 600/7 generated the most total biogas which was 6.096 mL/g COD. Biogas production at pH control was greater than that at pH noncontrol. At non-controlled pH, COD/N ratio of 600/7 had COD removal 3.21±0.49%. Whereas at controlled pH, COD/N ratio of 600/7 had COD removal 13.05±0.35%.

16.
Br Biotechnol J ; 2013 Oct; 3(4): 575-580
Artigo em Inglês | IMSEAR | ID: sea-162544

RESUMO

Aims: The dairy industry faces growing scrutiny of its environmental stewardship. The potential impact of an individual operation on the environment varies with animal concentration, weather, terrain, soils, and numerous other conditions. It is hoped that management practices found on dairy industry will benefit by the management practices. So properly applied the Management Practices, the factual study of dairy effluent by various physico-chemical characters concern for environmental health and safety. Study Design: Effluent samples were collected from dairy industries. The samples were characterized by physical parameters like pH, temperature, TS, etc. and chemical parameters BOD, COD, DO etc. Place and Duration of Study: Effluent samples were collected from dairy industry of district Kolhapur Maharashtra (India).Physico-chemical characteristics of the effluent during the months between March to August 2011. Methodology: Total 4 samples of dairy effluents were collected by composite sampling at the time 9, 12, 3, 6 o’clock per day and stored at 4oc for further analysis. Then on the next day in quintet it was subjected to analyze the physicochemical parameters like Temperature, pH, DO, TDS, TSS, TS, BOD, COD, chloride, Sulphate, oil and Grease. Results: The study revealed that the dairy effluent is slightly alkaline in nature, and high temperature, BOD & COD values obtained by the analysis of dairy effluents indicate the presence of heavy load of organic substances. Also a higher temperature and oils and Greases which lower the dissolved oxygen activities can cause serious problems in disposal of waste water. Above the standard value suspended and dissolved organic solids are responsible for creating nuisance. Conclusion: Dairy industry tested in this study was found high levels of pH, BOD, COD, TSS It is very important that proper waste water treatment systems should be installed for the protection of the environmental health and for the ecological balance.

17.
Eng. sanit. ambient ; 18(3): 253-262, July-Sept/2013. tab, graf
Artigo em Português | LILACS | ID: lil-690019

RESUMO

Os efluentes da planta de branqueamento da produção de pasta celulósica apresentam, além de elevadas concentrações de matéria orgânica em termos de Demanda Química de Oxigênio (DQO) e Demanda Bioquímica de Oxigênio (DBO) e cor, compostos com elevada toxicidade, o que torna o tratamento destes efluentes problemático. O objetivo do presente artigo é avaliar a biotratabilidade dos efluentes de branqueamento ácido e alcalino de polpa celulósica kraft por processos aeróbios e anaeróbios por meio da caracterização, utilizando parâmetros convencionais e coletivos. Os resultados de DQO inerte, biodegradabilidade aeróbia e anaeróbia, distribuição de massas molares, produtos microbianos solúveis e substâncias poliméricas extracelulares indicaram a baixa biotratabilidade dos efluentes.


The bleaching pulp mill effluent presents, in addition to high concentrations of organic matter in terms of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) and color, compounds with high toxicity, which makes the treatment of these effluents difficult. The aim of this article is to evaluate the biotreatability of acid and alkaline bleach effluents from kraft pulp by aerobic and anaerobic processes through characterization using conventional and collective parameters. The results of inert COD, aerobic and anaerobic biodegradability, molecular weight distribution, soluble microbial products and extracellular polymeric substances showed a low biotreatability of the effluents.

18.
Artigo em Inglês | IMSEAR | ID: sea-148177

RESUMO

Background & objectives: Apoptosis is considered as a major defense mechanism of the body. Multiple pathogens induce macrophage apoptosis as a mode of immune evasion. In earlier studies, n-3 polyunsaturated fatty acids (PUFA) have been reported to be protective against neuronal apoptosis and neuronal degeneration, seen after spinal cord injury. In this study, we tried to evaluate the role of n-3 polyunsaturated fatty acids on the process of macrophage phagocytic activity and apoptosis in mice. Methods: Mice were divided into three groups (n=60); Group I was fed on sea cod oil; Group II on flaxseed oil supplementation for 9 wk along with standard laboratory chow diet. Group III was fed on standard diet and served as control. After supplementation, phagocytic and apoptotic (morphological staining: acridine orange plus ethidium bromide; H-33342 plus propidium iodide staining and DNA ladder formation) activities of mouse alveolar macrophages were assessed. Results: Alveolar macrophages (obtained from sea cod oil and flaxseed oil fed group mice) showed significant increase in bacterial uptake as well as intracellular killing (P< 0.05) of Streptococcus pneumoniae. Significant decrease (P<0.05) in apoptotic cells was observed among alveolar macrophages from sea cod and flaxseed oil fed mice whereas maximum apoptosis was observed in control alveolar macrophages on interaction with bacteria in vitro which was confirmed by DNA laddering. Interpretation & conclusions: These findings suggest that dietary supplementation with n-3 polyunsaturated fatty acids to mice led to enhanced phagocytic capability of their alveolar macrophages as well as provided protection against apoptosis upon challenge with S. pneumoniae.

19.
Br Biotechnol J ; 2012 Oct; 2(4): 179-191
Artigo em Inglês | IMSEAR | ID: sea-162375

RESUMO

Present research was aimed towards designing and construction of efficient plastic media-trickling filter (TF) for the treatment of domestic wastewater. The hydraulic flow rate through the TF was maintained at 80±2 ml/min at a temperature range of 5-15ºC by selecting treatment time of 12, 24, 36 and 48 hrs. Parameters like COD, BOD5, TSS, turbidity, NO3, NO2, SO4, PO4 and pathogenic indicator microbes were monitored after treatment of 12, 24, 36 and 48 hrs. The efficiency of the TF was improved with increase of time from 12 to 48 hrs. Maximum efficiency of TF was observed after 48 hrs treatment viz. 93.45, 93, 86.25, 57.8, 63.15, 25, 32.43, 99.95 and 86.3% reduction from the zero time value for BOD5, COD, TSS, PO4, SO4, NO3, NO2, turbidity and fecal coliforms respectively. Finally 48 hrs treated sample was passed through sand filter (SF) for further final polishing and approximately, 95.72, 95, 100, 73.5, 65.8, 58.3, 37.83, 100 and 91.5% reduction in BOD5, COD, TSS, PO4, SO4, NO3, NO2, turbidity and fecal coliforms was observed. This study showed that plastic media-trickling filter along with sand filter is a promising technology for wastewater treatment and can be scaled up for small communities in the developing countries.

20.
Braz. j. microbiol ; 42(4): 1506-1515, Oct.-Dec. 2011. graf, tab
Artigo em Inglês | LILACS | ID: lil-614617

RESUMO

Treatment and safe disposal of tannery saline wastewater, a primary effluent stream that is generated by soaking salt-laden hides and skin is one of the major problems faced by the leather manufacturing industries. Conventional treatment methods like solar evaporation ponds and land composting are not eco-friendly as they deteriorate the ground water quality. Though, this waste stream is comprised of high concentration of dissolved proteins the presence of high salinity (1-6 percent NaCl by wt) makes it non-biodegradable. Enzymatic treatment is one of the positive alternatives for management of such kind of waste streams. A novel salt-tolerant alkaline protease obtained from P.aeruginosa (isolated from tannery saline wastewater) was used for enzymatic degradation studies. The effect of various physical factors including pH, temperature, incubation time, protein source and salinity on the activity of identified protease were investigated. Kinetic parameters (Km , Vmax) were calculated for the identified alkaline protease at varying substrate concentrations. Tannery saline wastewater treated with identified salt tolerant protease showed 75 percent protein removal at 6 h duration and 2 percent (v/v) protease addition was found to be the optimum dosage value.


Assuntos
Águas Residuárias/análise , Águas Salinas/análise , Purificação da Água/análise , Curtume/análise , Peptídeo Hidrolases/análise , Pseudomonas aeruginosa/isolamento & purificação , Microbiologia Ambiental , Métodos , Métodos , Amostras de Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA