La importancia de la determinación de la deuda de oxígeno en el perioperatorio / The importance of oxygen debt determination in the perioperative period

Resumen: El fenómeno de la deuda de oxígeno (dO2) descrito hace varias décadas en el contexto del ejercicio físico se ha incorporado progresivamente al terreno de la medicina. En particular se ha utilizado durante los cambios hemodinámicos producidos por la cirugía y la anestesia en los pacientes de alto riesgo. La dO2 se definió como el aumento en la cantidad de oxígeno consumida por el organismo inmediatamente después de realizar un ejercicio físico hasta que el consumo se normaliza nuevamente. En el perioperatorio se llega a producir cuando se presenta un desbalance entre la oferta (DO2) y la demanda de oxígeno (VO2) que lleva a hipoxia tisular. El grado de la dO2 tisular se ha relacionado directamente con la falla de órganos múltiples y morbimortalidad perioperatoria. A pesar de los avances en la medicina, aún no es posible prevenir o disminuir la dO2 con la administración de líquidos o con el uso de agentes vasoactivos. Por lo que un retardo o manejo inadecuado de la hemodinámica perioperatoria producirá hipoperfusión e hipoxia tisular afectando los resultados de la cirugía. El conocimiento y la valoración de la dO2 es esencial durante la anestesia del paciente de alto riesgo. Para lograr este objetivo se requiere del uso de índices adecuados que permitan detectar y cuantificar la hipoperfusión tisular y el desbalance entre la DO2 y la VO2. En esta revisión se presentan los conceptos fundamentales de la dO2, su mecanismo, detección y cuantificación; además de las intervenciones para evitarla o disminuirla y las recomendaciones para los anestesiólogos con el fin de asegurar mejores resultados en los pacientes quirúrgicos de alto riesgo.

Abstract: The phenomenon of oxygen debt (dO2) described several decades ago in the context of physical exercise has been incorporated into medicine, particularly during the hemodynamic changes produced by surgery and anesthesia in high-risk patients. dO2 is defined as the increase in the amount of oxygen consumed by the body immediately after physical exercise until O2 consumption returns to normal. In the perioperative period, an imbalance between oxygen supply (DO2) and demand (VO2) could generate dO2. The degree of tissue dO2 has been directly related to multiple organ failure and perioperative morbimortality. Despite advances in medicine, it is not yet possible to prevent or lower the dO2 with fluid administration or vasoactive agents. Delay or inadequate management of hemodynamics could produce tissue hypoperfusion and hypoxia, affecting surgery outcomes. Knowledge and assessing dO2 during perioperative are essential during anesthesia for high-risk patients. Adequate indices are required to detect and quantify tissue hypoperfusion and the imbalance between DO2 and VO2 during anesthesia. This review presents the mechanism, detection, and quantification of dO2. In addition to interventions to avoid or reduce dO2 and recommendations for anesthesiologists to ensure better results in high-risk surgical patients.

Physico-chemical and Microbiological Qualities of Abattoir Wastewater in Egbu, Imo State, Nigeria

Abbattoir waste water is of a complex composition. When discharged without being treated, poses a threat to human health and the environment. This is the practice common in Nigeria, and is worrisome.Objective: The aim of this study was to assess the physico-chemical and microbiological qualities of waste water from Egbu abattoir discharged into ‘Otamiri’ river in Owerri North local government area, Imo State, Nigeria.Methods: The microbial quality of abattoir wastewater was studied. The duration of the study was three months, from June to September, 2019. Sample collection was done in the morning (8-10am) and in the evening (4-6pm). A total of thirty samples (30) were collected from two sampling points, at the place of generation of the wastewater (Effluent source) and at the point of discharge into the river (POE). Standard methods were employed to assess the microbiological and physiochemical quality of the effluent. The microorganisms isolated from the samples included Escherichia coli, Salmonella, Staphylococcus, Aspergillus, Mucor, Listeria, Micrococcus and Candida species. The Total Heterotrophic Count (THC) of effluent samples, at source and POE were 8.51log10 cfu/ml and 6.15log10cfu/ml respectively, Total Coliform Count (TCC) for same samples were 6.77log10 cfu/ml and 4.56log10 cfu/ml respectively. The Total Fungal Count (TFC) of the effluent samples at source and at POE was 5.19log10 cfu/ml and 4.18log10 cfu/ml respectively. Results further revealed that the pH of the effluent at source was 6.58 while that at Point of Entry into the river was 7.30. The temperature of both samples was 25oC. The Total Dissolved Solid values of the effluent collected at source was higher, having a value of 1400mg/L against 1000mg/L at Point of Entry. Also the Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) values of the effluent at source were 5.10mg/L and 8.58mg/L respectively, while the BOD and COD of the water at the POE were 4.3mg/L and 7.9mg/L respectively.Conclusion: Abattoir wastes are becoming a major environmental health challenge and being discharged into the Otamiri River indiscriminately is of public health concern. The potential public health implications associated with discharging untreated abattoir wastewater into the environment and thus, the need for adequate treatment to ensure decontamination as well as providing wastewater treatment facility is imperative.

Medical effect of sports on improving the maximum oxygen / O efeito médico dos esportes na melhora da captação de oxigênio / El efecto médico de los deportes en la mejora de la captación de oxígeno

ABSTRACT Introduction: Maximum oxygen uptake is an effective indicator of the level of human cardiopulmonary function and aerobic work capacity. Observing the effects of aerobic training and formulating scientific training plans are of considerable value. Objective: To observe the effect of physical exercise on the human body's maximum oxygen uptake and arterial blood ketone body ratio. Methods: Before and after 4 weeks of physical exercise, the maximum oxygen uptake, blood lactic acid and heart rate changes, and ketone body content in the incremental load exercise experiment was measured in the human body. Results: The subjects' maximum oxygen uptake, maximum exercise load, heart rate, and blood lactic acid levels increased significantly after physical exercise. Conclusion: The human body's maximum oxygen uptake is enhanced under sports. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Introdução: A captação máxima de oxigênio é um indicador eficaz do nível da função cardiopulmonar e da capacidade de trabalho aeróbico humano. A observação dos efeitos de treinos aeróbicos e a formulação de planos de treinamento científicos têm valor considerável. Objetivo: Observar o efeito do exercício físico na captação máxima de oxigênio e a proporção de corpos cetônicos e sangue arterial no corpo humano. Métodos: Antes e após exercícios físicos de quatro semanas, a captação máxima de oxigênio, ácido láctico no sangue e mudanças na frequência cardíaca, além do conteúdo de corpos cetônicos, em um experimento de carga de exercícios progressiva foram medidos no corpo humano. Resultados: A captação máxima de oxigênio, carga máxima de exercício, frequência cardíaca e níveis de ácido láctico no sangue dos indivíduos aumentaram significativamente após o exercício físico. Conclusão: A captação máxima de oxigênio aumenta com a prática de esportes. Nível de evidência II; Estudos terapêuticos - investigação de resultados de tratamento.

RESUMEN Introducción: La captación máxima de oxígeno es un indicador eficaz del nivel de la función cardiopulmonar y de la capacidad de trabajo aeróbico humano. La observación de los efectos de entrenamientos aeróbicos y la formulación de planes de entrenamiento científicos tiene valor considerable. Objetivo: Observar el efecto del ejercicio físico en la captación máxima de oxígeno y la proporción de cuerpos cetónicos y sangre arterial en el cuerpo humano. Métodos: Se midió, en el cuerpo humano, antes y después de ejercicios físicos de 4 semanas, la captación máxima de oxígeno, ácido láctico en la sangre y cambios en la frecuencia cardíaca, además del contenido de cuerpo cetónicos, en un experimento de carga progresiva. Resultados: La captación máxima de oxígeno, carga máxima de ejercicio, frecuencia cardíaca y niveles de ácido láctico en la sangre de los individuos aumentaron significativamente tras el ejercicio físico. Conclusión: La captación máxima de oxígeno aumenta con la práctica de deportes. Nivel de evidencia II; Estudios terapéuticos - investigación de resultados de tratamiento.

Effect of physical exercise on increasing the maximum oxygen uptake of skeletal muscle / O efeito do exercício físico no aumento de captação máxima de oxigênio do musculo esquelético / El efecto del ejercicio físico en el aumento de consumo máximo de oxígeno del músculo esquelético

ABSTRACT Introduction: Aerobic exercise can improve the physical function of athletes and increase the oxygen content in skeletal muscles. This has a significant reference value for evaluating training effects and judging sports fatigue. Objective: Maximum oxygen uptake is one of the most critical indicators of aerobic work capacity. The thesis analyzes the medical promotion effect of physical exercise on the oxygen content of skeletal muscle. Methods: The thesis performed aerobic exercises on two groups of young rowers. Athletes in group A performed high-load exercise, and athletes in group B performed low-load exercise. At the same time, we placed a detector on the athletes' skeletal muscle to test the volunteer's muscle oxygen content and other physiological indicators. Results: Comparing high-load exercise and low-load exercise, the maximum oxygen uptake and the utilization rate of the maximum oxygen uptake when reaching the anaerobic net were 10% and 16% higher, respectively. There was no difference in the activity of muscle enzymes between the two groups. Conclusions: After aerobic training, the muscle's oxygen utilization capacity is strengthened. Physical exercise promotes the maximum oxygen uptake of skeletal muscles. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Introdução: O exercício aeróbico pode melhorar a função física de atletas e aumentar o conteúdo de oxigênio nos músculos esqueléticos. Isso tem valor referencial importante na avaliação de efeitos do treinamento e no julgamento da fadiga pela prática de esportes. Objetivo: A captação máxima de oxigênio é um dos indicadores cruciais da capacidade aeróbica. A tese analisa o efeito médico de se incentivar exercícios físicos para o conteúdo de oxigênio do músculo esquelético. Métodos: a tese realizou exercícios aeróbicos em dois grupos de jovens remadores. Os atletas do grupo A realizaram exercícios de alta carga; os atletas do grupo B realizaram exercícios de baixa carga. Ao mesmo tempo, colocamos um detector nos músculos esqueléticos dos atletas para testar o conteúdo de oxigênio no músculo e outros indicadores fisiológicos. Resultados: Ao compararmos exercícios de alta carga e de baixa carga, a captação máxima de oxigênio e o índice de utilização de captação máxima de oxigênio ao atingir o ganho aeróbico foram 10% e 16% mais altos, respectivamente. Não houve diferença na atividade de enzimas musculares entre os dois grupos. Conclusões: Após o treino aeróbico, a utilização de oxigênio do músculo se fortalece. O exercício físico promove a máxima captação de oxigênio dos músculos esqueléticos. Nível de evidência II; Estudos terapêuticos - investigação de resultados de tratamento.

RESUMEN Introducción: El ejercicio aeróbico puede mejorar la función física de atletas y aumentar el contenido de oxígeno en los músculos esqueléticos. Eso tiene valor referencial importante en la evaluación de efectos del entrenamiento y al juzgar la fatiga por la práctica de deportes. Objetivo: El consumo máximo de oxígeno es uno de los indicadores cruciales de la capacidad aeróbica. La tesis analiza el efecto médico de incentivar ejercicios físicos para el contenido de oxígeno del músculo esquelético. Métodos: La tesis realizó ejercicios aeróbicos en dos grupos de jóvenes remeros. Los atletas del grupo A realizaron ejercicios de alta carga, y los atletas del grupo B realizaron ejercicios de baja carga. Al mismo tiempo, pusimos un detector en los músculos esqueléticos de los atletas para probar el contenido de oxígeno en el músculo y otros indicadores fisiológicos. Resultados: Al comparar ejercicios de alta carga y de baja carga, el consumo máximo de oxígeno y el índice de utilización del consumo máximo de oxígeno al atingir el gano aeróbico fueron 10% y 16% más altos, respectivamente. No hubo diferencia en la actividad de enzimas musculares entre los dos grupos. Conclusiones: Tras el entrenamiento aeróbico, la utilización de oxígeno del músculo se fortalece. El ejercicio físico promueve el máximo consumo de oxígeno de los músculos esqueléticos. Nivel de evidencia II; Estudios terapéuticos - investigación de resultados de tratamiento.

Nutritional value, total dry matter losses, effluent production and pollutant potential in Brachiaria brizantha cv. Paiaguás grass / [Valor nutricional, perdas totais de matéria seca, produção e potencial poluidor de efluentes em silagem de Brachiaria brizantha cv. Paiaguás]

The objective of the present study was to evaluate losses, production and polluting potential of the effluent, nutritional value and aerobic stability of silages of Brachiaria brizantha cv. Paiaguás grass, in different particle sizes and compaction density in silage. Three theoretical particle sizes (TTP 5; 8 and 12mm) and three compaction densities (DC 550; 600 and 650kg/m3) were evaluated, distributed in a factorial design (3 x 3), with four repetitions. The highest volume of effluent was found in silages with higher compaction densities (600 and 650kg/m3) and lower TTP (5 and 8mm). The highest chemical oxygen demand and biochemical oxygen demand were registered in the treatment with TTP of 5mm and higher DC (600 and 650kg/m3). Greater in vitro digestibility of DM was verified in the silage chopped at 5 and 8mm. There was no break in aerobic stability for 216 hours. Silage with a low compaction density 550kg/m3 and processing with a theoretical particle size of 12mm reduces effluent losses. In general, the nutritional value of Paiaguás grass was not influenced by the treatments. Different particle sizes and compaction density did not change the aerobic stability of silages.(AU)

Objetivou-se avaliar perdas, produção e potencial poluidor do efluente, valor nutricional e estabilidade aeróbia de silagens do capim Brachiaria brizantha cv. Paiaguás, em diferentes tamanhos de partícula e densidade de compactação na ensilagem. Foram avaliados três tamanhos teóricos de partícula (TTP 5; 8 e 12mm) e três densidades de compactação (DC 550; 600 e 650kg/m3), distribuídos em arranjo fatorial (3 x 3), com quatro repetições. O maior volume de efluente foi verificado nas silagens com maiores densidades de compactação (600 e 650kg/m3) e menores TTP (5 e 8mm). As maiores demanda química de oxigênio e demanda bioquímica de oxigênio foram registradas no tratamento com TTP de 5mm e nas maiores DC (600 e 650kg/m3). Maior digestibilidade in vitro da MS (média de 57,2%) foi verificada na silagem picada a 5 e 8mm. Não houve quebra da estabilidade aeróbia durante 216 horas. A ensilagem com baixa densidade de compactação (550kg/m3) e o processamento com tamanho teórico de partículas 12mm reduzem as perdas por efluente. O valor nutricional da silagem de capim-paiaguás, em geral, não foi influenciado pelos tratamentos. Diferentes tamanhos de partícula e densidade de compactação não alteraram a estabilidade aeróbia das silagens.(AU)

"Ensamblaje" de macroinvertebrados acuáticos y su relación con variables fisicoquímicas en un río de montaña en Colombia

Debido a la influencia de diferentes actividades humanas, los ríos y su biodiversidad están bajo tensión. El objetivo de este estudio fue evaluar la diversidad de los macroinvertebrados acuáticos del río Jordán (Valle del Cauca) y su relación con variables fisicoquímicas. En el tramo evaluado (5 650 m) se realizan actividades de minería, captación de agua, ganadería, agricultura, recreación y ocupación ilegal del territorio. Se ubicó una estación de muestreo a 1 173 m.s.n.m. (E1), con vertimientos de agua residual doméstica. La segunda a 1 069 m (E2) se ubicó antes de la bocatoma del acueducto, y la tercera a 1 019 m (E3) después de la bocatoma. Se midieron las concentraciones de variables fisicoquímicas (n = 15). Los organismos fueron recolectados usando redes surber (0.36 m2, 500 µm), de pantalla (1.6 m2, 350 µm) y D-net (0.9 m2, 500 µm), evaluando la estructura del ensamblaje mediante categorías de abundancia. El ensamblaje de macroinvertebrados acuáticos se relacionó con las variables fisicoquímicas mediante un análisis de correspondencia canónica (ACC). Las variables fisicoquímicas mostraron que E3 fue la estación más contaminada. Se registraron 9 órdenes, 23 familias y 31 taxa. E3 presentó la menor riqueza y en E2 Rhagovelia fue dominante. El ACC mostró que las variables que mayor influencia tienen sobre el ensamblaje de macroinvertebrados son el oxígeno, la DBO5, los sólidos disueltos totales y la turbidez. Se concluye que la diversidad de macroinvertebrados acuáticos disminuye con el aumento de la materia orgánica posiblemente debido a los vertimientos residuales y disminución del caudal.

Because of the influence of different human activities, rivers and their associated biodiversity are under stress. The aim of this study was to evaluate the diversity of aquatic macroinvertebrates of the Jordán River and its relation to water quality. Mining, water harvesting, livestock, agriculture, recreation and illegal occupation of the territory; take place in the evaluated section (5 650 m). A sampling site was established at 1 173 m.a.s.l. (E1), here the river receives wastewater. The second, at 1 069 m.a.s.l. (E2) was set up before the intake of an aqueduct. And the third, at 1 019 m.a.s.l. (E3) after the inlet pipe. Concentrations of physicochemical variables (n = 15) were measured. Aquatic macroinvertebrates were collected in gravel, pebbles and macrophytes using Surber nets (0.36 m2, 500 µm), a screen net (1.6 m2, 350 µm) and a D-net (0.9 m2, 500 µm). The assemblage structure was assessed using abundance categories. The diversity of aquatic macroinvertebrate and physicochemical variables were associated using canonical correspondence analysis (CCA). The physicochemical variables showed that E3 was the most contaminated site. There were 9 orders, 23 families and 31 taxa. E3 had the lowest richness and in E2 Rhagovelia was dominant. The CCA showed that variables that have the greatest influence on the diversity of macroinvertebrates are oxygen, BOD5, Total Dissolved Solids (TDS) and turbidity. It is concluded that the diversity of macroinvertebrates decreases with increasing organic matter possibly due to sewage and flow decrease.

Insights into the microbial community structure of anaerobic digestion of municipal solid waste landfill leachate for methane production by adaptive thermophilic granular sludge

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.

Feasibility Analysis of Removal of Alkaloids from Processing Wastewater of Aconiti Radix by Flocculation / 中国实验方剂学杂志

Objective: To investigate the removal effect of 5 kinds of common flocculants on 6 kinds of toxic alkaloids in processing wastewater of Aconiti Radix. Method: HPLC was employed to determine contents of 6 kinds of alkaloids in the processing wastewater of Aconiti Radix before and after flocculation.The mobile phase consisted of acetonitrile-tetrahydrofuran(25:15)-0.1 mol·L-1 ammonium acetate solution(each 1 L contains 0.5 mL of glacial acetic acid) for gradient elution, volume flow rate was 1.0 mL·min-1, detection wavelength was 235 nm.The removal characteristics and effects of five common flocculants of ferric chloride, aluminum sulfate, polymeric ferric sulfate, polyaluminum chloride/polyacrylamide(PAC/PAM) and sodium polyacrylate were compared and preliminarily optimized. Result: The 5 kinds of flocculants had certain selectivity for different types of alkaloids, and the removal of 6 kinds of alkaloids showed obvious differences.Among them, the PAC/PAM attenuated relative superiority, when the pH 6, adding amount of 0.25 g·L-1 and PAC-PAM dosing ratio of 30:1, comprehensive removal effect was relatively good, removal rates of mesaconitine and hypaconitine was 85.4%and 58.3%, respectively. Conclusion: The flocculation method can be used as a pretreatment process to reduce the toxicity of processing wastewater of Aconiti Radix.

A Point of Care Testing System for Chemical Oxygen Demand Based on Graphene Oxide-Nickel Nanoparticles Modified Electrode / 分析化学

An electrochemical analysis system for rapid determination of chemical oxygen demand ( COD) in flow state was established. A planar electrode modified with GO-NiNPs was matched with a 3D printed thin-layer cell. The sample was driven smoothly through the electrode surface by a micro peristaltic pump and then measured by chronoamperometry. The effect of modified materials, dielectric and electrochemical operating conditions were investigated. The whole response time of COD was 1. 5 min and the demand for the sample was about 2 mL. It turned out that the linear range of response in the low concentration region was 0. 15-100 mg/L, the linear equation was i(μA)=3. 974c (mg/L)+0. 2295 (r = 0. 9991) and the detection limit was 0. 04 mg/L. The linear response range in the high concentration region was 100-450 mg/L, and the linear equation was i(μA)=1. 938c (mg/L)+ 230. 9 (r = 0. 9877). Compared with the national standard method (GB11914-89) for measuring the actual water samples (Qinhuai River, Xuanwu Lake and Nanjing tap water), the correlation between them was quite good and the analysis time was dropped to 1/100. This new sensing system provided an environmentally friendly and portable method for detection of COD without using expensive, highly corrosive and toxic reagents.

Delineamento Box-Behnken para remoção de DQO de efluente têxtil utilizando eletrocoagulação com corrente contínua pulsada / Box-Behnken design for COD removal of textile wastewater using electrocoagulation with pulsed DC

RESUMO A remoção de poluentes de efluentes industriais de forma efetiva e economicamente viável ainda é um desafio. Dessa forma, o presente trabalho propôs investigar a tecnologia de eletrocoagulação (EC) para o tratamento de efluente têxtil utilizando corrente contínua pulsada (CCP). A metodologia de superfície de resposta Box-Behnken foi utilizada para analisar e otimizar as condições operacionais, visando à máxima remoção de demanda química de oxigênio (DQO). Os experimentos foram realizados com um volume reacional de 2,6 L, em modo batelada. Diante dos resultados obtidos, a configuração ótima considerada foi: velocidade de agitação = 200 rpm, frequência dos pulsos = 1.000 Hz e espaçamento entre os eletrodos = 1 mm, em 50 minutos de EC. Nessas condições foi obtida uma remoção de DQO de 81,23% (valor remanescente de 152 mg O2.L-1). Em adição, verificou-se que o processo de EC também é eficaz para a redução de cor, turbidez, sólidos suspensos totais, sulfato e sulfeto. A concentração de íons cloreto não foi alterada durante a EC, apresentando-se como um aspecto favorável para a reutilização do efluente tratado no próprio processo produtivo têxtil, o qual demanda uma elevada concentração de NaCl.

ABSTRACT The effective and economically viable removal of industrial wastewater pollutants is still a challenge. Thus, this study proposed to investigate the electrocoagulation technology (EC) for the treatment of textile effluent using pulsed direct current (CCP). The methodology of Box-Behnken response surface was used to analyze and optimize the operating conditions, aimed at maximum chemical oxygen demand (COD) removal. The experiments were performed with a reaction volume of 2.6 L in batch mode. Based on these results, the optimal configuration was: agitation speed = 200 rpm, frequency of pulses = 1,000 Hz and spacing between electrodes = 1 mm, in 50 minutes of EC. Under these conditions it was obtained a COD removal of 81.23% (remainder value of 152 mg O2.L-1). In addition, it was found that the EC process is also effective for reduction of color, turbidity, total suspended solids, sulfate and sulfide. The concentration of chloride ions was not modified during the EC, presenting itself as a favorable aspect for the reuse of treated wastewater in the textile production process itself, which demands a high concentration of NaCl.

Modelagem da progressão da DBO obtida na incubação de esgoto doméstico sob diferentes temperaturas / Modeling of BOD progression obtained in sewage incubated under different temperatures

RESUMO Confiável quantificação da demanda bioquímica de oxigênio exercida (DBO exercida) poderá ser obtida com incubação das amostras sob temperaturas diferentes, desde que o valor da demanda bioquímica de oxigênio última (DBOU) não seja alterado nessas condições. Alguns autores têm relatado aumento no valor da DBOU com a elevação da temperatura de incubação das amostras, o que pode ser decorrente da ocorrência da nitrificação, da aclimatação diferenciada ou do mau ajuste dos modelos de progressão da demanda bioquímica carbonácea de oxigênio (DBO exercida). Neste estudo, objetivou-se avaliar o efeito da temperatura sobre a progressão da DBO exercida e o valor da DBOu em amostras de esgoto doméstico bruto, avaliando-se qual modelo melhor se ajusta aos dados obtidos. Os resultados indicaram pequena influência da temperatura de incubação das amostras nos valores da DBOU do esgoto sanitário e que os modelos de primeira e segunda ordens descreveram adequadamente a progressão da DBO exercida.

ABSTRACT Reliable quantification of biochemical oxygen demand exerted (exerted BOD) can be obtained by incubating samples at different temperatures, since the amount of ultimate biochemical oxygen demand (UBOD) does not change in these conditions. Some authors have found increased UBOD values with rise in temperature of incubating samples, which could be due to the occurrence of nitrification, the acclimatization or the inadequacy of modeling of carbonaceous oxygen demand (exerted BOD) progression. This study aimed to evaluate the effect of temperature on the progression of exerted BOD and UBOD values in samples of raw domestic sewage, checking which model best fits the data. The results indicated low influence of incubating sewage samples temperature on UBOD values, being that both models, first and second order, described properly the exerted BOD progression.

Reator anaeróbio tipo UASB conjugado com processo Fenton para remoção de cor e demanda química de oxigênio de água residuária sintética de indústria têxtil / Anaerobic reactor type UASB conjunction with process Fenton to remove color and chemical oxygen demand textile industry of synthetic wastewater

RESUMO A contaminação por despejos de efluentes industriais têxteis tem sido uma preocupação emergente de pesquisadores e ambientalistas, pois esses apresentam composição extremamente heterogênea e grande quantidade de material tóxico e recalcitrante, o que dificulta seu tratamento. Durante o processamento têxtil, uma ampla gama de corantes é liberada e alguns desses, como os azo corantes, que se caracterizam pela função azo (-N=N-) ligada a grupos aromáticos e podem ser tóxicos, carcinogênicos e/ou mutagênicos. Em vista disso, esta pesquisa teve como principal objetivo avaliar os benefícios da utilização de um reator anaeróbio tipo reator anaeróbico de fluxo ascendente com manta de lodo (UABS), seguido de processo oxidativo avançado (POA) do tipo Fenton na degradação de cor e demanda química de oxigênio (DQO) de efluente sintético de indústria têxtil. Com os resultados, foram verificadas remoções de DQO em torno de 82,0% para o reator UASB e de 95,6% para o conjunto. A cor alcançou 96,1% de remoção no reator UASB e 100,0% ao final do processo.

ABSTRACT Contamination by textile industrial wastewater discharges has been an emerging concern of researchers and environmentalists, as they have extremely heterogeneous composition and loads of toxic and recalcitrant material, which complicates treatment. In the textile processing, a wide range of dye is released and some of these, such as dyes, azo, characterized by the feature azo (-N=N-) attached to aromatic groups and may be toxic, carcinogenic and/or mutagenic. In view of this, this research aimed to evaluate the benefits of using an anaerobic reactor type anaerobic reactor upflow sludge blanket (UABS), followed by advanced oxidation process (AOP) type Fenton in color degradation and chemical oxygen demand (COD) of synthetic textile industry effluent. From the results of COD removal was observed at around 82.0% for the UASB reactor and 95.6% for the group. The color reached 96.1% removal in UASB reactor and 100.0% at the end of the process.

Biofilm Reactor-Based Online Biochemical Oxygen Demand Measurement and Instrument Design / 分析化学

A buofulm reactor ( BFR ) was fabrucated vua a cultuvatuon process usung naturally occurrung mucrobual seeds from locally collected wastewaters, and a serues of researches were carrued out wuth thus BFR based onlune Buochemucal Oxygen Demand ( BOD) monutor. The results showed that the BFR cultuvatuon tume was less than 14 h, and the buodegradatuon effucuencues was 18. 5%. The munumum detectuon lumut was 0. 5 mg/L, as well as the upper detectuon lumut was 20 mg/L. The relatuve error and relatuve standard devuatuon un accuracy and long term stabuluty to standard were -0. 8% and ±3. 2%, respectuvely. The real sample determunatuons showed an average relatuve error of +5. 6% to conventuonal BOD5 method. The BFR mauntauned a good performance un long term stabuluty and accuracy durung thus test peruod, and the broad lunear range ensured the demand for surface water onlune monutorung.

Biodegradation of deproteinized potato wastewater and glycerol during cultivation of Rhodotorula glutinis yeast

Background Deproteinized potato wastewater and glycerol are two by-products which are difficult to dispose. The objective of this study was to determine the ability of Rhodotorula glutinis to use glycerol and nitrogen compounds present in deproteinized potato wastewater and to evaluate the ability of simultaneous biodegradation of potato wastewater and glycerol via microbiological methods. Results It has been found that R. glutinis used glycerol and potato wastewater as a source of carbon and nitrogen, respectively. The highest degree of glycerol content (70.6%) reduction was found after cultivation of the investigated strain using a medium with 5% glycerol. In this medium, a significant reduction in the total protein content, estimated at 61%, was observed. The process of 72 h cultivation of yeast in a medium containing potato wastewater and 5% glycerol reduced the chemical oxygen demand (COD) more than 77%. Supplementation of media with high doses of glycerol (i.e. 20 and 25%) led to decreased metabolic activity in the yeast strain tested. Conclusion It has been found that there is a possibility of simultaneous biodegradation of potato wastewater and glycerol during the cultivation of R. glutinis.

Phytoremediation of Textile Waste Water Using Potential Wetland Plant: Eco Sustainable Approach.

One of the major problems encountered in the textile industry is the production of large volumes of highly coloured wastewater. The textile industries daily discharge million litres of untreated effluents in the form of wastewater into public drains that eventually empty into rivers. They cause serious health hazard. Textile wastewater also contains substantial pollution loads which increase the Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended solids (TSS), Total Dissolved Solids (TDS) and heavy metals. So pre-treatment is needed prior to discharge of these effluents. Among all method investigated presently, Phytoremediation by AMATS (Aquatic Macrophytes Treatment Systems) is a well established environmental protective technique. The most common aquatic Macrophytes being employed in wastewater treatment are water hyacinth, penny wort, water lettuce, water ferns and duck weeds, because they are cheaper to construct and a little skill is required to operate them. This review paper discusses comparative study and efficiency of plants and proposed mechanism of various plant contributed for remediation of textile waste water.

Use of Palm Oil Mill Effluent as Medium for Cultivation of Chlorella sorokiniana.

Aims: Palm oil mill effluent (POME) erodes the principal biophysical characteristic of both soil and water when discharged untreated but could be exploited as medium for microalgae cultivation due to its vast mineral contents. Place and Duration of study: POME samples were collected from a local palm oil processing mill at Nsukka, Enugu State, Nigeria. A part of the study was done at the Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan while the rest at the University of Nigeria, Nsukka between March and September, 2012. Methodology: Chlorella sorokiniana C212 was grown in several Batches (A-D) of POME supplemented with urea (60 mg/L) before subjecting to different sterilization protocols. Cultivation was conducted in shaker flasks at 150 rpm, 1 vvm, 3000 lux and pH 7.0±0.2. Results: The filter sterilized Batch (B) promoted the highest (1070±30 mg/L) dry cell weight (DCW), lipid (156±12 mg/g-cell) and chlorophyll (1.59±0.11 mg/g-cell) contents while chemical oxygen demand (COD) decreased by 45±08%. The autoclaved medium (Batch A) gave the least DCW (310±20 mg/L), lipid production (40±05 mg/g-cell) and chlorophyll content (0.58±0.02 mg/g-cell) while COD reduced by 20±04%. The highest COD decrease (70±05%) was achieved in the unsterilized Batch (D). Batch B was most positively affected by dilution because at 75% concentration, DCW increased to 1360±30 mg/L, lipid contents to 174±10 mg/g-cell, chlorophyll to 1.87±0.14 mg/g-cell the while COD declined by 63±03%. Conclusions: POME has potential for use in microalgae cultivation with significant saving in treatment costs.

Municipal wastewater treatment and kinetic studies using immobilized fixed bed anaerobic digester.

This study was designed to evaluate the performance of a cylindrical immobilized fixed Bed. Anaerobic digester in treating diluted municipal waste water. A series of three independent batch experiments was performed for a total operation time of 28 days. The system of anaerobic digestion showed stability conditions, with no noticeable scum or foaming problems. The anaerobic treatment of diluted municipal waste water is done using immobilized fixed bed anaerobic batch reactor. The source of waste generation is a mixed sludge collected from dock yard. The present study, thus initiated a need based experimental work on anaerobic digester incorporated with immobilized poly urethane foam system. The kinetic parameters are also estimated using experimental data. Empirical relations were developed for the characteristics like BOD, COD, SCOD, TDS and TSS using modeling equations.

Two Rapid Ana1ysis Methods of BOD5 / 环境与健康杂志

Biochemical oxygen demand of 5 days (BOD 5) was a very important parameter of monitoring ofwater quality. The classical method presented some shortcomings,such as complexity, long period, requirementof high technology and not promptly reflecting the pollution levels of water body, so it was of no significance fortreatment of industrial waste water. In this paper, two rapid methods for determination of BODs, raising incubation temperature and correlative estimation method, were introduced and their advantages, such as short period and simplicity of operation were verified by experiments. Modification of classical method was of certain instructive significance for the practical application to treatment of industrial waste water and forecast of pollutionlevels of water body.

Evaluation of Uncertainty of Chemical Oxygen Demand Measure in Drinking Water / 环境与健康杂志

Objective To estimate the marginal value of the chemical oxygen demand (COD) in drinking water by evaluation of uncertainty. Methods According to Evaluation and Expression of Uncertainty in Measurement (JJF1059-1999), analysis of measure uncertainty of the chemical oxygen demand determined by acidic potassium permanganate titrate prescribed in Sanitary Standards for Drinking Water (2001) was conducted. Results The type A relative standard uncertainty was 0.584%, type B was 0.781%, in which the sub-item uncertainty led by using 25 ml burette was 0.708%, the water sample volume was 0.056%, the adjusted potassium permanganate standard solution was 0.325%; the relative combined standard uncertainty was 0.975%, the expanded uncertainty was 1.95%. Conclusion According to the result of the uncertainty (3.08?0.06) mg/L, COD in the polluted sample exceeds the limit, the use of 25 ml burette produced the most contribution to the uncertainty.

Comparison of 3 Methods for Determination of Chemical Oxygen Demand of Water / 环境与健康杂志

ve To compare the advantage and disadvantages of spectrophotometry assay, microwave di-gestion and standard circumfluence method for determination of chemical oxygen demand (COD) in various water samples. Methods The levels of COD of the water samples were determined by spectro-photometry, microwave di-gestion and standard circumfluence method respectively. Results The relative standard variations were 4.3% ~ 9.59% for spectrophotometry, 3.58% ~5.61% for microwave digestion method and 4.03% ~ 4.27% for standard circumfluence method. The recovery rates of adding standard material were 90% -95% , 90% ~96% and 90% ~98% respectively. Conclusion The microwave digestion method showed easy, rapid and accurate. It presented good practical prospect in monitoring environmental samples.