Evaluation of the Steam Explosion Pretreatment Upon the Anaerobic Digestion of Water Hyacinth Biomass: Influence on Liquid and Solid Fractions

Biochemical methane potential tests were performed to evaluate the effects of steam explosion on the liquid and solid substrates of thermal hydrolysis pretreatment applied to water hyacinth biomass. The operational conditions of the thermal hydrolysis applied the combination of two temperatures (170 and 210 ºC) and two cooking times (5 and 30 min). The higher solubilization factor was 22.9% for the sample pretreated at 210 ºC and 30 min followed by steam explosion effect (TH + SE). Steam explosion, temperature and time were, in order of importance, the more effective operational conditions for the biomass solubilization. The sample 210 ºC - 5 min TH + SE presented the higher methane production increase, in relation to the raw substrate, resulting in a increment factor of 2.43, for the solid sample. The higher methane production increase for the liquid sample was on a factor of 1.67, for sample 210 ºC - 30 min TH + SE. The higher biomethanization increase considering both biomass factors (solid + liquid) was obtained for the pretreatment 170 ºC - 30 min TH + SE. A combined model confirmed the hydrolysis limitation for the solid samples biodegradation; however, it was not clear for the prediction on the liquid samples. Micrographs evidenced the morphological changes of the solid substrate with the solubilization increase. Particle size reduction was the most effective effect of the pretreatment on the substrate morphology. Porosity increment was observed only in the surface of the sample 210 ºC - 30 min TH + SE

Nutrient removal using a UASB reactor followed by a high-rate pond and DAF

O despejo de efluentes parcialmente tratados com presença de nutrientes pode causar eutrofização nos corpos hídricos. Para evitar este processo, é necessário o devido tratamento que visa a melhoria na qualidade final do efluente a ser lançado. Este trabalho apresenta o tratamento de esgoto doméstico a partir de reator anaeróbio de manto de lodo (UASB) seguido de lagoa de alta taxa de algas (LAT) com posterior separação da biomassa algal através da flotação por ar dissolvido (FAD) operado durante um ano. O reator UASB foi operado com vazão de 1.6 m³/h e TDH de 10.8 h. A LAT foi operada com vazão de 0.8 m³/h e com TDH de 4.1 dias. Para o auxílio na flotação, foram realizados testes com o coagulante inorgânico cloreto férrico com dosagem de 40 mg/L e comparado com testes utilizando o floculante orgânico Tanfloc SG® com uma dosagem de 50 mg/L, operado com vazão de1.7m³/h e TDH de 40 minutos. O sistema UASB + LAT apresentou remoção média de nitrogênio total Kjeldahl (NTK) de 61.3 ± 11.2 % e para o fósforo total de 32.3 ± 5.5 %. Os resultados dos testes de flotação mostraram que o cloreto férrico obteve desempenho superior para a remoção de fósforo total, atingindo valores de 74.5 ± 7.5 %. Já o Tanfloc SG apresentou maior capacidade de remoção de sólidos suspensos voláteis e matéria orgânica (DQO) com valores de 88.2 ± 4.3 % e 89.8 ± 4.2 %, respectivamente.The discharge of partially treated effluents with nutrients may cause eutrophication in water bodies. To avoid this process due treatment is necessary to improve the final quality of the effluent to be released. This work presents the treatment of domestic sewage from an Upflow Anaerobic Sludge Blanket (UASB) followed by a high algal rate lagoon (LAT) with subsequent separation of algal biomass by dissolved air flotation (FAD) operated for one year. The UASB reactor was managed at a flow rate of 1.6 m³/h and a HRT of 10.8 h. The pond was worked at a flow rate of 0.8 m³/h with a HRP of 4.1 days. Inorganic coagulant ferric chloride with a dosage of 40 mg/L and organic flocculant Tanfloc SG with a dosage of 50 mg/L were tested to assist the flotation system. The UASB+LAT system showed an average TKN removal of 61.3 ± 11.2 % and the total phosphorus 32.3 ± 5.5 %. The overall removal observed in the pond and separations tests showed that ferric chloride showed a higher performance in the removal of total phosphorus reaching values of 74.5 ± 7.5 %. On the other hand, Tanfloc SG performed better for the removal of volatile suspended solids and organic matter with up to 88.2 ± 4.3 % and 89.8 ± 4.2 %, respectively

Anaerobic treatment of finishing-tannery wastewater in association with membranes

O presente artigo versa sobre tratamento anaeróbio auxiliado com membranas de micro e ultrafiltração tratando efluente de curtume de acabamento. Na planta piloto foi utilizado um reator de mistura completa e as pressões de operação nas membranas de micro e ultrafiltração forma de 8 kgf/cm2, 6 kgf/cm2 e 4 kgf/cm2 nas três etapas de estudo. As eficiências médias relativas a remoção de DQO variaram de 68% a 82%. A remoção de cromo média foi acima de 95% nas três etapas de estudo. Este artigo também comenta o comportamento de taninos e sólidos totais e voláteis. Verificou-se que para efluentes de curtume de acabamento este processo apresentou uma eficiência acima do esperado para diversos parâmetros, possibilitando a utilização do efluente tratado em alguns banhos no processo de curtimento e outras finalidades como limpeza de pisos e pátios.This paper present anaerobic treatment of finishing tannery wastewater, associated with micro and ultrafiltration. At the pilot plant was used a CSTR. The operation pressures on the micro and ultrafiltration membranes were 8 kgf/cm2, 6 kgf/cm2 and 4 kgf/cm2 in the three steps of this research. The COD removal efficiencies were from 68% to 82%. Chromium removal was more than 95% in the three steps of this research. This paper also comment the behavior of the tannins, volatile and total solids. It was observed that this process when used to finishing tannery wastewater treatment showed a high efficiency of removal in severals parameters making possible the utilization of treated wastewater in some baths in the tannery process and others purposes like floors and yards cleaning

Anaerobic treatment of finishing-tannery wastewater in association with membranes

O presente artigo versa sobre tratamento anaeróbio auxiliado com membranas de micro e ultrafiltração tratando efluente de curtume de acabamento. Na planta piloto foi utilizado um reator de mistura completa e as pressões de operação nas membranas de micro e ultrafiltração forma de 8 kgf/cm2, 6 kgf/cm2 e 4 kgf/cm2 nas três etapas de estudo. As eficiências médias relativas a remoção de DQO variaram de 68% a 82%. A remoção de cromo média foi acima de 95% nas três etapas de estudo. Este artigo também comenta o comportamento de taninos e sólidos totais e voláteis. Verificou-se que para efluentes de curtume de acabamento este processo apresentou uma eficiência acima do esperado para diversos parâmetros, possibilitando a utilização do efluente tratado em alguns banhos no processo de curtimento e outras finalidades como limpeza de pisos e pátios.This paper present anaerobic treatment of finishing tannery wastewater, associated with micro and ultrafiltration. At the pilot plant was used a CSTR. The operation pressures on the micro and ultrafiltration membranes were 8 kgf/cm2, 6 kgf/cm2 and 4 kgf/cm2 in the three steps of this research. The COD removal efficiencies were from 68% to 82%. Chromium removal was more than 95% in the three steps of this research. This paper also comment the behavior of the tannins, volatile and total solids. It was observed that this process when used to finishing tannery wastewater treatment showed a high efficiency of removal in severals parameters making possible the utilization of treated wastewater in some baths in the tannery process and others purposes like floors and yards cleaning

Optimization of a carboard paper factory wastewater treatment plant

Este trabalho versa sobre a utilização de uma estratégia de otimização de uma estação de tratamento de efluentes de uma indústria de embalagens de papel, com problemas de “foaming”. Os resultados do diagnóstico inicial mostraram que o tratamento primário alcançou uma eficiência superior a 70% na remoção de sólidos suspensos. As modificações operacionais realizadas foram limpezas das caixas de gordura, redução da geração de óleos e graxas nos pontos de geração. As modificações no processo na ETE foram à implementação da equalização da vazão de alimentação do tanque de aeração, adição de hipoclorito de sódio na entrada do sedimentador secundário, adição de ácido fosfórico para equilibrar a relação entre nutrientes e DBO5 e a manutenção de uma concentração e idade do lodo constante durante o processo.This paper describes the strategies used to optimize a cardboard paper factory wastewater treatment plant regarding operational problems caused by the occurrence of foaming and filamentous organisms. The operational modifications involved the use of an equalization tank, the reduction of oil and grease from the industrial process, the addition of sodium hypochlorite at the inlet of the secondary settler to control filamentous organisms and phosphoric acid to correct the nutrients balance and BOD. A correct value of biomass concentration and sludge age were maintained constant all the time. The first results showed that the TSS removal efficiency in the primary settler was higher than 70%, followed by an improved performance of the biological reactor due to the control of filamentous organisms and better performance of the secondary settler