Evaluation of the efficiency of anaerobic reactors in the removal of pollutants from fish processing effluents / Avaliação da eficiência de reatores anaeróbios na remoção de poluentes em efluentes do processamento de pescado

The objective of the present work was to evaluate the performance of a compartmentalized anaerobic reactor (CAR) followed by anaerobic filter in real scale, effluent treatment from fish fridge processing. The work was developed in a fish fridge located in the south of the state of Minas Gerais, which has an effluent treatment plant composed of static screen, grease removal device, CAR reactor and anaerobic filter. The monitoring happened trough physical-chemical parameters of fluids and effluents from all sampling points of the plant biweekly. The parameters evaluated were temperature, pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), volatile suspended solids (VSS), volatile fatty acids (VFA) and alkalinity. Operational problems found in the primary treatment were not limiting for the system performance, which managed to meet the parameters of environmental legislation in Minas Gerais according to the efficiency of removal of COD, BOD and VSS from wastewater from fish processing.

O presente trabalho teve como objetivo avaliar o desempenho de reator anaeróbio compartimentado (RAC) seguido por filtro anaeróbio em escala real tratando efluentes do processamento de frigorífico de pescado. O trabalho foi desenvolvido em um frigorífico de pescado localizado no sul do estado de Minas Gerais, que possui uma estação de tratamento de efluentes composta por peneira estática, caixa de gordura, reator ABR e filtro anaeróbio. O monitoramento do sistema consistiu em um conjunto de análises físico-químicas dos afluentes e efluentes de todos os pontos de coleta de amostras da estação de tratamento coletados quinzenalmente. Os parâmetros avaliados foram temperatura, pH, demanda química de oxigênio (DQO), demanda bioquímica de oxigênio (DBO), sólidos suspensos totais (SST), sólidos suspensos voláteis (SSV), ácidos voláteis totais (AVT) e alcalinidade. Problemas operacionais encontrados no tratamento primário não foram limitantes para o sistema, que conseguiu atender parâmetros da legislação ambiental de Minas Gerais quanto à eficiência de remoção de DQO, DBO e SSV das águas residuárias do processamento de pescado. O sistema de tratamento é uma alternativa promissora para o tratamento de efluentes do processamento de pescado.

Efficiency of the anaerobic baffled reactor followed by anaerobic filter in the removal of nutrients and pathogenic organisms in fish processing effluents / [Eficiência do reator ABR seguido de filtro anaeróbio na remoção de nutrientes e de organismos patogênicos em efluentes de processamento de pescado]

The aquaculture showed high growth along with the increase in the consumption of animal protein from this sector. The processing industries facilitate the preparation of fish for the consumer; however, they generate large volumes of effluents with a high polluting potential. Environmental legislation establishes norms for the release of effluents, making it necessary to implement treatment systems to reduce the pollutants generated. The objective of this work was to evaluate the performance of a compartmentalized anaerobic reactor (ABR) followed by an anaerobic filter (AF) treating fish processing effluent. The work was carried out in a slaughterhouse that had an effluent treatment station consisting of a static sieve, grease box, ABR reactor and anaerobic filter. Monitoring consisted of physical-chemical and biological analyzes of samples collected from the influent and effluents from each stage of treatment. The parameters evaluated were ammonia, nitrite, nitrate, NTK, phosphate and coliforms. The average results of the removal efficiency of these parameters, respectively, for the ABR reactor were 5, 40, 69, -19, -25 and 83%, and for the AF -0.5, 73, 53, 10, -17 and -17%. The system composed by the ABR reactor followed by the Anaerobic Filter showed high removal of nitrite, nitrate, and coliforms.

A atividade de aquicultura apresentou elevado crescimento, juntamente com o aumento do consumo de proteína animal proveniente desse setor. As indústrias de processamento facilitam o preparo do pescado ao consumidor, todavia geram grandes volumes de efluentes de alto potencial poluidor. A legislação ambiental estabelece normas para o lançamento de efluentes, tornando necessária a implementação de sistemas de tratamento para a redução dos poluentes gerados. O objetivo deste trabalho foi avaliar o desempenho de um reator anaeróbio compartimentado (ABR) seguido por filtro anaeróbio (FA), tratando efluente de processamento de pescado. O trabalho foi desenvolvido em um frigorífico que possuía uma estação de tratamento de efluentes composta por peneira estática, caixa de gordura, reator ABR e filtro anaeróbio. O monitoramento consistiu em análises físico-químicas e biológicas de amostras coletadas do afluente e dos efluentes de cada etapa do tratamento. Os parâmetros avaliados foram: amônia, nitrito, nitrato, NTK, fosfato e coliformes. Os resultados médios da eficiência de remoção desses parâmetros, respectivamente, do reator ABR foram de 5, 40, 69, -19, -25 e 83%, e do FA -0,5, 73, 53, 10, -1, e -17%. O sistema composto pelo reator ABR seguido pelo filtro anaeróbio apresentou alta remoção de nitrito, nitrato e coliformes.

Ammonia determines transcriptional profile of microorganisms in anaerobic digestion

Anaerobic digestion is important for the management of livestock manure with high ammonia level. Although ammonia effects on anaerobic digestion have been comprehensively studied, the molecular mechanism underlying ammonia inhibition still remains elusive. In this study, based on metatranscriptomic analysis, the transcriptional profile of microbial community in anaerobic digestion under low (1500 mg L-1) and high NH4 + (5000 mg L-1) concentrations, respectively, were revealed. The results showed that high NH4 + concentrations significantly inhibited methane production but facilitated the accumulations of volatile fatty acids. The expression of methanogenic pathway was significantly inhibited by high NH4 + concentration but most of the other pathways were not significantly affected. Furthermore, the expressions of methanogenic genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase were significantly inhibited by high NH4 + concentration. The inhibition of the co-expressions of the genes which encode acetyl-CoA decarbonylase was observed. Some genes involved in the pathways of aminoacyl-tRNA biosynthesis and ribosome were highly expressed under high NH4 + concentration. Consequently, the ammonia inhibition on anaerobic digestion mainly focused on methanogenic process by suppressing the expressions of genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase. This study improved the accuracy and depth of understanding ammonia inhibition on anaerobic digestion.(AU)

Crude glycerin in anaerobic co-digestion of dairy cattle manure increases methane production

Anaerobic digestion of crude glycerin (CG) along with animal waste has been an excellent option for increasing the production of biogas and methane to achieve efficiency in the treatment of both residues. This study aimed to evaluate improvements in specific productions of biogas and methane, reductions in solid and fibrous components in substrates prepared with dairy cattle manure and CG (containing 14 % glycerol). With these residues, experimental substrates were prepared and placed in 25 batch digesters. Initial content of the TS in the influent was 4 % and CG was added in increasing doses (0, 5, 10, 15 and 20 % relative to total solids (TS) of the influent). Results were submitted to ANOVA and orthogonal contrasts to assess the effects of linear and quadratic order and thereby estimate the optimal CG doses through the adjusted models. The highest values for specific production of methane (0.19 and 0.26 L g-1 of TS and volatile solids (VS) added, respectively) were reached with the CG inclusions of 6 and 8 %, respectively. Total production of biogas with the inclusion of 6 % CG was 11 % higher when compared to the control treatment. The largest reduction in VS (48 %) was achieved with the addition of 4 % CG. Addition of CG at levels between 3 and 8 % improved the efficiency of the process of anaerobic digestion with dairy cattle manure.

Crude glycerin in anaerobic co-digestion of dairy cattle manure increases methane production

Anaerobic digestion of crude glycerin (CG) along with animal waste has been an excellent option for increasing the production of biogas and methane to achieve efficiency in the treatment of both residues. This study aimed to evaluate improvements in specific productions of biogas and methane, reductions in solid and fibrous components in substrates prepared with dairy cattle manure and CG (containing 14 % glycerol). With these residues, experimental substrates were prepared and placed in 25 batch digesters. Initial content of the TS in the influent was 4 % and CG was added in increasing doses (0, 5, 10, 15 and 20 % relative to total solids (TS) of the influent). Results were submitted to ANOVA and orthogonal contrasts to assess the effects of linear and quadratic order and thereby estimate the optimal CG doses through the adjusted models. The highest values for specific production of methane (0.19 and 0.26 L g-1 of TS and volatile solids (VS) added, respectively) were reached with the CG inclusions of 6 and 8 %, respectively. Total production of biogas with the inclusion of 6 % CG was 11 % higher when compared to the control treatment. The largest reduction in VS (48 %) was achieved with the addition of 4 % CG. Addition of CG at levels between 3 and 8 % improved the efficiency of the process of anaerobic digestion with dairy cattle manure.(AU)

Swine wastewater treatment using an anaerobic baffled (ARB) and a UASB reactor system / Sistema reator anaeróbio de chicanas - reator UASB no tratamento de efluentes de suinocultura

The purpose of this study was to assess the swine wastewater treatment system, consisting of the anaerobic baffled reactor (ABR), followed by the upflow anaerobic sludge blanket (UASB) reactor at full scale. The system was monitored by analyzing samples collected in the influent and effluent of ABR and UASB. The following parameters were analyzed: temperature, pH, total suspended solids (TSS), volatile suspended solids (VSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Averages of total removal of COD and BOD were 96.7 and 98.4%, respectively. The mean concentrations of COD, BOD, TSS, and VSS at the final effluent were 611, 124, 138, and 134 mg L-1, respectively. The mean volumetric organic loadings (VOL) at the ABR and UASB were 10.29 and 0.99 kg COD m-1d-1. Therefore, the ABR-UASB system was found to be a promising alternative for the swine wastewater treatment.

O objetivo deste trabalho foi avaliar o sistema de tratamento de águas residuárias de suinocultura, constituído de reator anaeróbio de chicanas (RAC), seguido por reator anaeróbio de manta de lodo (UASB), em escala real. O sistema foi monitorado por meio da análise de amostras coletadas nos afluentes e efluentes do RAC e UASB. Foram analisados os seguintes parâmetros: temperatura, pH, sólidos suspensos totais (SST), sólidos suspensos voláteis (SSV), demanda bioquímica de oxigênio (DBO) e demanda química de oxigênio (DQO). As médias de remoção total de DQO e de DBO foram 96,7 e 98,4%, respectivamente. As concentrações médias de DQO, DBO, SST e SSV no efluente final foram 611, 124, 138 e 134 mg.L-1, respectivamente. As cargas orgânicas volumétricas (COV) médias no RAC e UASB foram 10,29 e 0,99 kgDQO m kgDQO m-3d-1. Desta maneira, o sistema RAC-UASB apresenta-se como alternativa promissora para o tratamento de águas residuárias de suinocultura.

Swine wastewater treatment using an anaerobic baffled (ARB) and a UASB reactor system / Sistema reator anaeróbio de chicanas - reator UASB no tratamento de efluentes de suinocultura

The purpose of this study was to assess the swine wastewater treatment system, consisting of the anaerobic baffled reactor (ABR), followed by the upflow anaerobic sludge blanket (UASB) reactor at full scale. The system was monitored by analyzing samples collected in the influent and effluent of ABR and UASB. The following parameters were analyzed: temperature, pH, total suspended solids (TSS), volatile suspended solids (VSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Averages of total removal of COD and BOD were 96.7 and 98.4%, respectively. The mean concentrations of COD, BOD, TSS, and VSS at the final effluent were 611, 124, 138, and 134 mg L-1, respectively. The mean volumetric organic loadings (VOL) at the ABR and UASB were 10.29 and 0.99 kg COD m-1d-1. Therefore, the ABR-UASB system was found to be a promising alternative for the swine wastewater treatment.(AU)

O objetivo deste trabalho foi avaliar o sistema de tratamento de águas residuárias de suinocultura, constituído de reator anaeróbio de chicanas (RAC), seguido por reator anaeróbio de manta de lodo (UASB), em escala real. O sistema foi monitorado por meio da análise de amostras coletadas nos afluentes e efluentes do RAC e UASB. Foram analisados os seguintes parâmetros: temperatura, pH, sólidos suspensos totais (SST), sólidos suspensos voláteis (SSV), demanda bioquímica de oxigênio (DBO) e demanda química de oxigênio (DQO). As médias de remoção total de DQO e de DBO foram 96,7 e 98,4%, respectivamente. As concentrações médias de DQO, DBO, SST e SSV no efluente final foram 611, 124, 138 e 134 mg.L-1, respectivamente. As cargas orgânicas volumétricas (COV) médias no RAC e UASB foram 10,29 e 0,99 kgDQO m kgDQO m-3d-1. Desta maneira, o sistema RAC-UASB apresenta-se como alternativa promissora para o tratamento de águas residuárias de suinocultura.(AU)

Phosphorus distribution and availability in untreated and mechanically separated biogas digestates

Biogas digestates contain valuable nutrients but also have high water contents. Di-gestates were sampled from two different biogas facilities before and after solid-liquid separation and were analyzed with regard to their composition and phosphorus (P) fractions. Additionally, to investigate the P fertilizer effects of these digestates in comparison with undigested slurry or TripleSuper-P (TSP), they were applied in a pot experiment (6 kg soil per pot) in an amount corresponding to 200 mg P per pot in combination with various crops (amaranth, maize, maize + beans mixed cropping, sorghum). A separation of digestates resulted in higher P concentrations of the solid fraction in comparison with the liquid fraction. The proportion of the readily soluble P fractions (H2O-P, NaHCO3-P) to the total P was higher than 70 % in all digestates. The digestates increased P uptake of the tested crops and concentrations of bioavailable P in the soil to the same extent as highly soluble TSP. Activities of soil enzymes were lower after application of the digestates in comparison to unfermented slurry. The fertilizer management of digestates can be improved by a solid-liquid separation since the solid fraction showed a relatively high concentration of P resulting in a reduction in application doses required to meet the P demands of crops.

Phosphorus distribution and availability in untreated and mechanically separated biogas digestates

Biogas digestates contain valuable nutrients but also have high water contents. Di-gestates were sampled from two different biogas facilities before and after solid-liquid separation and were analyzed with regard to their composition and phosphorus (P) fractions. Additionally, to investigate the P fertilizer effects of these digestates in comparison with undigested slurry or TripleSuper-P (TSP), they were applied in a pot experiment (6 kg soil per pot) in an amount corresponding to 200 mg P per pot in combination with various crops (amaranth, maize, maize + beans mixed cropping, sorghum). A separation of digestates resulted in higher P concentrations of the solid fraction in comparison with the liquid fraction. The proportion of the readily soluble P fractions (H2O-P, NaHCO3-P) to the total P was higher than 70 % in all digestates. The digestates increased P uptake of the tested crops and concentrations of bioavailable P in the soil to the same extent as highly soluble TSP. Activities of soil enzymes were lower after application of the digestates in comparison to unfermented slurry. The fertilizer management of digestates can be improved by a solid-liquid separation since the solid fraction showed a relatively high concentration of P resulting in a reduction in application doses required to meet the P demands of crops.(AU)

Treatment of swine manure: case studies in Europeans N-surplus areas

In this study, eight different manure treatment plants were monitored. The plants were four on-farm and four centralized treatment plants, all of them at full-scale level. Assessment includes a total of seven pre-treatment and process units as follows: mechanical separation, with and without coagulant and flocculant addition, pasteurization, nitrification-denitrification, anaerobic digestion, and composting. The plants are located in nutrient surplus areas of three European Member States (Spain, Italy and Denmark), the majority of these areas being Nitrate Vulnerable Zones (NVZ). Results presented herein are data collected over a six-month period and comprise performance data of the treatment plants, pathogen indicators (E.coli and Salmonella) and greenhouse gas (GHG) emissions data under two scenarios: 1) the baseline scenario and 2) the treatment plant scenario. The assessment includes GHG emissions of the storage facilities, transportation, and subsequent intermediate storage, electric consumption, electric production, composting, and land application. All treatment plants studied generated a significant reduction in GHG emissions (between 53 and 90 %) in comparison to the baseline scenario. Organic matter and total solids (TS) content in manure were also greatly reduced, with values ranging between 35-53 % of chemical oxygen demand (COD) and, 24-61 % of TS for anaerobic digestion (AD) treatment plants, 77-93 % COD and 70 % TS in the case of AD combined with nitrogen (N)-removal unit plants. Nitrogen concentrations were also greatly reduced (between 65-85 %) total Kjeldahl nitrogen (TKN) and 68-83 % ammonium (NH4+-N)) in plants with N-removal units.

Treatment of swine manure: case studies in Europeans N-surplus areas

In this study, eight different manure treatment plants were monitored. The plants were four on-farm and four centralized treatment plants, all of them at full-scale level. Assessment includes a total of seven pre-treatment and process units as follows: mechanical separation, with and without coagulant and flocculant addition, pasteurization, nitrification-denitrification, anaerobic digestion, and composting. The plants are located in nutrient surplus areas of three European Member States (Spain, Italy and Denmark), the majority of these areas being Nitrate Vulnerable Zones (NVZ). Results presented herein are data collected over a six-month period and comprise performance data of the treatment plants, pathogen indicators (E.coli and Salmonella) and greenhouse gas (GHG) emissions data under two scenarios: 1) the baseline scenario and 2) the treatment plant scenario. The assessment includes GHG emissions of the storage facilities, transportation, and subsequent intermediate storage, electric consumption, electric production, composting, and land application. All treatment plants studied generated a significant reduction in GHG emissions (between 53 and 90 %) in comparison to the baseline scenario. Organic matter and total solids (TS) content in manure were also greatly reduced, with values ranging between 35-53 % of chemical oxygen demand (COD) and, 24-61 % of TS for anaerobic digestion (AD) treatment plants, 77-93 % COD and 70 % TS in the case of AD combined with nitrogen (N)-removal unit plants. Nitrogen concentrations were also greatly reduced (between 65-85 %) total Kjeldahl nitrogen (TKN) and 68-83 % ammonium (NH4+-N)) in plants with N-removal units.(AU)

Tratamento de efluentes de abatedouro de frangos por meio de reator UASB seguido de filtro anaeróbio / Treatment of waste water poultry slaughter house through UASB reactor followed by anaerobic filter

O Brasil é um dos maiores produtores de aves do mundo e se destaca na exportação de carne de frango, que tem papel relevante na economia do país. Como resultado do crescimento da indústria de processamento do frango, há também um significativo aumento na geração de efluentes. Uma alternativa interessante para o tratamento desses resíduos são os reatores anaeróbios. Este trabalho teve como objetivo avaliar o desempenho do sistema reator UASB-Filtro anaeróbio no tratamento de efluentes de abate de frangos. O estudo foi desenvolvido em um abatedouro avícola, situado na região metropolitana de Belo Horizonte, Minas Gerais. O sistema de tratamento foi composto por peneira estática, caixa de gordura, reator UASB e filtro anaeróbio. A vazão média diária de efluentes do abatedouro foi de 30m³/dia. A carga orgânica aplicada no reator UASB foi de 0,71kg DQO/m³.d. O monitoramento do sistema foi realizado por meio de análises físico-químicas do afluente e dos efluentes da caixa de gordura, reator UASB e filtro anaeróbio. Os parâmetros avaliados foram: temperatura, pH, demanda química de oxigênio (DQO), demanda bioquímica de oxigênio (DBO), sólidos suspensos totais (SST), e sólidos suspensos voláteis (SSV). Os valores efluentes médios encontrados para DBO, DQO e SST foram 106, 290 e 56mg/L, respectivamente. A eficiência de remoção do sistema para DBO variou de 83 a 99%, e para DQO de 50 a 98%. A eficiência de remoção média de SST e SSV foi de 92%. Conclui-se que o sistema reator UASB seguido de filtro anaeróbio apresentou alto desempenho na remoção de sólidos e carga orgânica. Dessa forma, esses reatores tornam-se uma alternativa viável para o tratamento de águas residuárias de frigoríficos, já que oferecem bons resultados de remoção de poluentes.(AU)

Brazil is one of the largest poultry producers in the world and stands out in exportation of chicken meat, which plays an important role in the economy. As a result of the growth of the poultry processing industry, there is also a significant increase in the generation of wastewater. An interesting alternative for the treatment of such wastes is anaerobic. This study aimed to evaluate the performance of the system UASB reactor-anaerobic filter on wastewater treatment of slaughtering chickens. The study was conducted in a poultry slaughterhouse located in the metropolitan region of Belo Horizonte, Minas Gerais. The treatment system was composed of static sieve, grease trap, UASB reactor and anaerobic filter. The daily average flow of effluent from the abattoir was 30m³/day. The organic load applied to the UASB reactor was 0.71kg COD/m³.d. The monitoring system was performed by means of physico-chemical analysis of the influent and effluent of fat, UASB reactor and anaerobic filter. The parameters evaluated were: temperature, pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (SS) and volatile suspended solids (VSS). The mean values for effluent BOD, COD and SS were 106, 290 and 56mg/L, respectively. The removal efficiency of BOD to the system ranged 83-99% for COD and 50-98%. The average removal efficiency of SS and SSV were 92%. We conclude that the system UASB reactor followed by anaerobic filter showed high performance in removing solids and organic load. Thus, these reactors become a viable alternative for treating wastewater slaughterhouses, offering good results in removing pollutants.(AU)

Avaliação de reator anaeróbio de manta de lodo no tratamento de efluentes de frigorífico / Evaluation of reactor anaerobic sludge blanket in the treatment of wastewater slaughterhouse

O presente trabalho objetivou avaliar a eficiência em escala real de um sistema de tratamento de efluentes de frigorífico. A estação de tratamento de efluentes em escalareal foi projetada para uma vazão diária de 60 m³/d, correspondente a um abate de 60 bovinos por dia. O sistema de tratamento composto de uma calha parshall, para medição de vazão, seguida de peneira estática, caixa de gordura gravimétrica, decantador e reator anaeróbio de manta de lodo (UASB) foi monitorado semanalmente entre janeiro e agosto de 2012. Foram analisados os seguintes parâmetros: pH, alcalinidade, demanda bioquímica de oxigênio (DBO), demanda química de oxigênio (DQO), sólidos totais (ST), sólidos suspensos totais (SST), nitrogênio amoniacal e nitrogênio total Kjedhall. Os valores efluentes médios de pH, DQO e SST no reator UASB foram de 6,96; 660 mg/L e 188 mg/L, respectivamente. O sistema mostrou-se eficiente, com remoção média de 96,40% para DQO e 89,92% para SST. O reator UASB apresentou alta performance na remoção de sólidos e carga orgânica. Dessa forma, esse reator torna-se uma alternativa viável para o tratamento de águas residuárias de frigoríficos, já que oferece bons resultados de remoção e baixo custo de implantação.

This study aimed to evaluate the efficiency of a full-scale treatment system effluent slaughterhouse. The full-scale Sewage Treatment Station was designed for a daily flow of 60 m³/d, corresponding to a slaughter of 60 cattle per day. The treatment system consists of a Parshall flume for flow measurement, followed by static sieve, gravimetric fat, sedimentation and anaerobic sludge blanket (UASB) box and it was monitored weekly from January to August. The following parameters were analyzed: pH, alkalinity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), total suspended solids (TSS), ammonia nitrogen, and total nitrogen kjedhall. The average pH, COD and TSS in the UASB reactor effluent values were 6.96, 660 mg/L and 188 mg/L , respectively. The system proved to be efficient, with average removal of 96.40% to 89.92% for COD and TSS. The UASB reactor showed high performance in removing solids and organic load. Thus, this reactor becomes a viable alternative for treating wastewater slaughterhouse, offering good removal results and low cost of deployment.

Avaliação de reator anaeróbio de manta de lodo no tratamento de efluentes de frigorífico / Evaluation of reactor anaerobic sludge blanket in the treatment of wastewater slaughterhouse

O presente trabalho objetivou avaliar a eficiência em escala real de um sistema de tratamento de efluentes de frigorífico. A estação de tratamento de efluentes em escalareal foi projetada para uma vazão diária de 60 m³/d, correspondente a um abate de 60 bovinos por dia. O sistema de tratamento composto de uma calha parshall, para medição de vazão, seguida de peneira estática, caixa de gordura gravimétrica, decantador e reator anaeróbio de manta de lodo (UASB) foi monitorado semanalmente entre janeiro e agosto de 2012. Foram analisados os seguintes parâmetros: pH, alcalinidade, demanda bioquímica de oxigênio (DBO), demanda química de oxigênio (DQO), sólidos totais (ST), sólidos suspensos totais (SST), nitrogênio amoniacal e nitrogênio total Kjedhall. Os valores efluentes médios de pH, DQO e SST no reator UASB foram de 6,96; 660 mg/L e 188 mg/L, respectivamente. O sistema mostrou-se eficiente, com remoção média de 96,40% para DQO e 89,92% para SST. O reator UASB apresentou alta performance na remoção de sólidos e carga orgânica. Dessa forma, esse reator torna-se uma alternativa viável para o tratamento de águas residuárias de frigoríficos, já que oferece bons resultados de remoção e baixo custo de implantação.(AU)

This study aimed to evaluate the efficiency of a full-scale treatment system effluent slaughterhouse. The full-scale Sewage Treatment Station was designed for a daily flow of 60 m³/d, corresponding to a slaughter of 60 cattle per day. The treatment system consists of a Parshall flume for flow measurement, followed by static sieve, gravimetric fat, sedimentation and anaerobic sludge blanket (UASB) box and it was monitored weekly from January to August. The following parameters were analyzed: pH, alkalinity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), total suspended solids (TSS), ammonia nitrogen, and total nitrogen kjedhall. The average pH, COD and TSS in the UASB reactor effluent values were 6.96, 660 mg/L and 188 mg/L , respectively. The system proved to be efficient, with average removal of 96.40% to 89.92% for COD and TSS. The UASB reactor showed high performance in removing solids and organic load. Thus, this reactor becomes a viable alternative for treating wastewater slaughterhouse, offering good removal results and low cost of deployment.(AU)

Insights into impacts of temperature and organic load in anaerobic reactors treating effluents from fish processing industry

O aumento da produção mundial de pescado resulta em um consequente aumento de efluentes gerados pela indústria de processamento. Devido à sua composição, esse tipo de efluente requer soluções particulares de tratamento. Diversas alternativas têm sido sugeridas, como o uso de processos biológicos para a degradação da matéria orgânica através de microrganismos. Entretanto, estudos sobre o microbioma de lodos de reatores anaeróbios que tratam efluentes de processamento de peixes ainda são escassos. Com o objetivo de avaliar os efeitos da temperatura no tratamento da digestão anaeróbia de efluentes de processamento de pescado, reatores anaeróbios replicados em escala piloto foram operados a 20C e 37C por 60 dias, sendo avaliados por análises físico-químicas e metagenômica. Os resultados demonstraram que os reatores a 37C foram estatisticamente superiores no dia 50 na remoção da demanda química de oxigênio (DQO) e o enriquecimento das famílias hidrolíticas e acidogênicas Porphyromonadaceae, Rikenellaceae e Spirochaetaceae pode ter contribuído para que os reatores a 37C tenham tido melhor desempenho. No entanto, para uma melhor compreensão do processo, um segundo ensaio experimental foi desenhado para avaliar não apenas a temperatura, mas a influência da taxa de carga orgânica aplicada (COV), realizado utilizando-se a mesma metodologia. De maneira diferente, os reatores a 37°C apresentaram acúmulo de ácidos graxos voláteis (AGV), o que levou a uma remoção superior da matéria orgânica a 20°C. A família Anaerobaculaceae, presente apenas a 37°C, foi sugerida como intimamente ligada aos altos níveis de AGV nesses reatores. Diferentemente do primeiro experimento, as principais famílias envolvidas em ambas as temperaturas foram Ectothiorhodospiraceae, Syntrophorhabdaceae, Dethiosulfovibrionaceae e Synergistaceae, apresentando diferentes abundâncias. Em conjunto, esses resultados fornecem dados sobre a regulação de comunidades biológicas complexas pela temperatura e COV em reatores anaeróbios usados para tratar águas residuárias do processamento de peixes.

The increase of fish production worldwide results in a consequent increase of generated effluents by processing industries. Due to its composition, this type of wastewater requires particular treatment solutions. Several alternatives have been suggested, such as the use of biological processes for the degradation of organic matter through microorganisms. However, studies on microbiome from anaerobic reactors sludge treating fish processing wastewater are still scarce. In order to evaluate temperature effects on anaerobic digestion treatment of fish processing effluents, replicated pilot-scale anaerobic reactors were operated at 20C and 37C for 60 days, being evaluated through physicochemical analysis and a metagenomic approach. The results demonstrated that 37C reactors were statistically superior from day 50 in chemical oxygen demand (COD) removal and the enrichment of hydrolytic and acidogenic Porphyromonadaceae, Rikenellaceae, and Spirochaetaceae families may have contributed to 37C reactors improved performance. However, to a better understanding of the process, a second experiment trial was designed to evaluate not only the temperature, but the influence of the applied organic load rate (OLR), which was done using the same methodology. In a different way, the 37°C reactors showed volatile fatty acids (VFA) accumulation, which lead to superior organic matter removal at 20°C. The Anaerobaculaceae family, present only at 37°C, was suggested as closely linked to high VFA levels in these reactors. Differently from the first trial, the main involved families in both temperatures were Ectothiorhodospiraceae, Syntrophorhabdaceae, Dethiosulfovibrionaceae and Synergistaceae, appearing with different abundances. Taking together, these results provide insights about the regulation of complex biological communities by temperature and OLR in anaerobic reactors used to treat fish processing wastewater.

Emissões de metano entérico e das fezes, parâmetros fermentativos ruminais e comportamento ingestivo de bovinos alimentados com caroço de algodão e vitamina E

A problemática das emissões de gases de efeito estufa atribuída à produção de bovinos e melhorias na produtividade desses animais vem crescendo e se tornando cada vez mais importante. Bovinos emitem metano como parte do seu processo digestivo, e isto representa perda de energia para o animal. A decomposição das fezes geram metano, este pode ser recuperado por biodigestores e transformado em diferentes tipos de energia. Assim, objetivou-se quantificar o potencial de produção do metano entérico e da decomposição anaeróbia das fezes, bem como avaliar parâmetros ruminais e comportamentais de bovinos alimentados com caroço de algodão e vitamina E. Foram utilizadas seis vacas fistuladas não gestantes e não lactantes. Os tratamentos foram: 1) Controle: dieta basal; 2) CA: dieta basal mais 30% de caroço de algodão; 3) CAVitE: dieta basal mais 30% de caroço de algodão mais 500 UI vitamina E. O delineamento experimental utilizado foi o quadrado latino. Os resultados foram comparados por contrastes ortogonais e foram considerados significantes valores de P0,05. Não foram verificadas diferenças para o consumo de matéria seca (MS), bem como digestibilidade da MS e da fibra em detergente neutro (FDN). Os animais suplementados com caroço de algodão passaram maior tempo comendo e ruminando e menor tempo em ócio. Houve redução na concentração e produção de acetato, butirato e da relação acetato:propionato dos animais que receberam caroço de algodão comparado ao controle. A inclusão do caroço de algodão provocou mitigação das emissões de metano entérico. Houve alteração nas características dos substratos utilizados para abastecer os biodigestores. No entanto, não foram verificadas diferenças para a produção total de biogás, rendimento de metano e capacidade dos biodigestores em recuperar a energia das fazes na forma de metano. A inclusão de 30% caroço de algodão pode ser utilizada como estratégia para mitigar metano entérico, sem causar perdas no consumo, digestibilidade dos alimentos e na biodigestão anaeróbia das fezes. Além disso, promoveu alterações favoráveis no comportamento ingestivo, nos produtos da fermentação ruminal, bem como na partição de energia do trato gastrointestinal. A vitamina E pode ser utilizada como fonte antioxidante sem causar prejuízos para a fermentação ruminal e biodigestão anaeróbia das fezes.

Problems about greenhouses gas emissions attributed to cattle production and improvements in the productivity of these animals has been growing and becoming increasingly important. Cattle releases methane as part of their digestive process, and this represents loss of energy for the animal. The decomposition of feces releases methane and it can be recovered by digesters and transformed into different types of energy. Thus, aiming to quantify the potential production of enteric methane and anaerobic fecal decomposition, as well as to evaluate ruminal and behavioral parameters of cattle fed with cottonseed and vitamin E. Six cannulated cows were distributed in a replicate 3x3 Latin square. Treatments were: 1) control diet; 2) CS: basal diet plus 30% cottonseed and 3) CSVitE: basal diet plus 30% of cottonseed plus 500 UI of vitamin E. Results were compared through orthogonal contrast and values were considered significant when P0,05. No differences were observed for dry matter intake (DMI), as well as digestibility of DM and neutral detergent fiber (NDF). Animals supplemented with cottonseed spent more time eating and ruminating and less time in idles. Reduction in the concentration and production of acetate, butyrate and the acetate: propionate ratio was observed to animals fed cottonseed compared to the control. Enteric methane mitigation was observed for the cottonseed treatments compared to the control. Changes in the substrates characteristics used to load the digesters were observed. However, no differences were verified for the total biogas production, methane yield and capacity to recover the energy of the feces in the form of methane. Inclusion of 30% cottonseed can be used as a strategy to mitigate enteric methane, without causing losses in the DMI, nutrients digestibility and anaerobic digestion of feces. In addition, it promoted favorable changes in the ingestive behavior, ruminal fermentation products, as well as in the energy partition of the gastrointestinal tract. Vitamin E can be used as an antioxidant source without causing losses to ruminal fermentation and anaerobic digestion of feces.

COMPOSIÇÃO QUÍMICA E PRODUÇÃO DE BIOGÁS DOS DEJETOS DE SUÍNOS SOB RESTRIÇÃO ALIMENTAR E SUPLEMENTAÇÃO COM RACTOPAMINA E CROMO

Objetivou-se quantificar a produção de dejetos e biogás de suínos em terminação alimentados com cinco dietas: controle; restrição qualitativa; restrição quantitativa; cromo e ractopamina. Foram utilizados dez digestores semicontínuos de bancada, com capacidade para 7,5 L de substrato. Foram realizadas análises das produções de dejetos para determinação de matéria natural (MN), matéria seca (MS), matéria mineral (MM) e matéria orgânica (MO). Foram realizadas análises do afluente e efluente, para determinação dos teores de sólidos totais (ST) e sólidos voláteis (SV), mensuração dos valores de pH, nitrogênio amoniacal (N amoniacal), alcalinidade parcial (AP), alcalinidade intermediária (AI) e alcalinidade total (AT), concentração de nitrogênio total (N) e concentração de fósforo total (P total). Os dados de produção de dejetos e monitoramento do processo de digestão anaeróbia foram submetidos à análise de variância por meio dodelineamento em blocos ao acaso, em que as semanas de análises foram consideradas como blocos (cofator). Os dados foram analisados estatisticamente pelo teste de ScootKnott, utilizando-se 5% de probabilidade. Não foram observadas diferenças entre as dietas nas produções de dejetos na matéria natural (MN), matéria seca (MS), matéria mineral (MM) e matéria orgânica (MO). Suínos em terminação, dos 100 aos 120 kg de peso corporal, alimentados com as dietas estudadas, produziram 671 g de dejetos por dia, dos quais 218 g são MO e 147 g de matéria mineral (MM). Animais que receberam a dietacontrole apresentaram o maior coeficiente de resíduo (CR) (1,12) e não houve diferença entre as demais dietas. Não foram observadas diferenças entre as dietas para ST, pH e N Total dos afluentes e efluentes. O maior rendimento de biogás (574 mL g-1 de SV adicionados) foi obtido com os digestores abastecidos com dejetos de animais que receberam dieta qualitativamente restrita, seguido do tratamento controle (305 mL g-1 de SV adicionados), da restrição quantitativa (160mL g-1 de SV adicionados), cromo (104 mL g-1de SV adicionados) e ractopamina (127 mL g-1 de SV adicionados). Conclui-se que a dieta com restrição qualitativa resulta em maior produção de dejetos, porém com menores excreções de nitrogênio e fósforo e maior rendimento de biogás.

The aim was to quantify the manure production and thus their biogas yieldsby finishing pigs fed with five diets: control; qualitative restriction; quantitative restriction; with chromium and with ractopamine. Ten semi-continuous bench digesters with capacity of 7.5 L of substrate were used. Analyses were performed in order to determine natural matter (MN), dry matter (DM), mineral matter (MM) and organic matter (OM). Analyses were performed in order to determine the values of pH, and total solids (TS), volatile solids (VS), total ammonia nitrogen (TAN), partial alkalinity (PA), intermediate alkalinity (AI), total alkalinity (AT), total Kjeldahl nitrogen (TKN) and total phosphorus (Total P) concentration. Data from manure production and parameters of the anaerobic digestion process were submitted to analysis of variance through a randomized complete block design, in which the weeks (from weekly analyses) were considered ascofactor. The data were evaluated through the Scoot-Knott test, at 5% of probability. There was no difference amongmanure productions based on fresh matter (FM), dry matter (DM), mineral matter (MM) and organic matter (OM). Finishing pigs, from 100 to 120 kg of body weight, fed the different diets produced 671 g of manure per day (FM), in which 218g represented OM and 147 g of mineral matter (MM).Swine fed with diet control presented the highest waste coefficient (1.12) and there was no difference for other diets.The diets did not affect the pH values, TS and TKN contents of the affluents and effluents of the digesters. The highest biogas yield (574 mL g-1 VS added) was obtained with manure from pigs fed with a qualitative restriction diet, followed by control treatment (305 mLg-1VS added), quantitative restriction (160 mL g-1VS added), with chromium (104mL g-1 VS added) and with ractopamine (127 mL g-1 VS added) diets. Qualitative restriction has higher manure production, however with lower excretions of nitrogen and phosphorus and higher biogas yield.

PRODUÇÃO DE BIOGÁS POR DEJETOS DE SUÍNOS EM CRESCIMENTO E TERMINAÇÃO ALIMENTADOS COM DIFERENTES NÍVEIS DE ENERGIA LÍQUIDA

O objetivo do presente trabalho foi avaliar a eficiência do processo de digestão anaeróbia por dejetos de suínos em crescimento e terminação alimentados com dietas contendo diferentes níveis de 2300; 2380; 2460; 2540; 2620 e 2700 kcal kg-1 de energia líquida (EL) na dieta e estimar as características químicas dos dejetos e efluentes com intuito de verificar a produção acumulada de biogás e potencial de produção de biogás dos dejetos de animais com diferentes pesos corporais (50, 70 e 100 kg). O experimento foi conduzido no Laboratório de Resíduos de Origem Animal da Universidade Estadual de Mato Grosso do Sul, Unidade Universitária de Aquidauana (MS). Analisaram-se qualitativamente os teores de sólidos totais (ST), sólidos voláteis (SV), sólidos fixos (SF), potencial de hidrogênio (pH), nitrogênio total (N - Total) e fósforo (P - total) dos dejetos. O ensaio de digestão anaeróbia foi conduzido em um período total de 130 dias dos quais 40 dias de partida e 90 dias de cargas diárias. Utilizaram-se 12 digestores semicontínuos, de bancada, com volume útil de 7,5 L. Foram realizadas análises semanais dos substratos e efluentes dos digestores mensurando-se os valores de pH, nitrogênio amoniacal (N amoniacal), alcalinidade parcial (AP), alcalinidade intermediária (AI) e a alcalinidade total (AT) e teores de ST, SV e SF, produção de biogás (m3) e potenciais de produção de biogás dos dejetos (m3kg1), e quinzenais para quantificação da concentração de N - total e P - total. Os dados de ST, SV e SF foram submetidos ao delineamento experimental inteiramente casualizado, em que os dados para cada peso corporal foram analisados separadamente, com seis tratamentos e quatro repetições; e os dados de potencial de produção de biogás dos SV adicionados nos digestores foram submetidos ao delineamento em blocos ao acaso em que as semanas de avaliação foram consideradas como cofator, com seis tratamentos e quatro blocos. Os dados também foram analisados separadamente por peso corporal. Para comparação de médias, foi realizado o teste de Scott-Knott a 5% de probabilidade. Os níveis de energia líquida, de 2300 a 2700 kcal kg-1 da dieta alteraram a composição dos dejetos quanto aos teores de ST e SF. Para N - total e P - total dos dejetos os animais na faixa de 100 kg de peso corporal apresentaram máximos teores de 0,81 a 1,88 %, respectivamente. Os valores dos parâmetros de monitoramento (pH, N amoniacal e alcalinidade) apresentaram-se satisfatórios para o processo. Os teores de ST, SV e SF dos substratos e efluentes indicaram que houve degradação de parte da matéria orgânica durante o processo fermentativo. Após os 98 dias todos os tratamentos mantiveram-se em uma faixa de produção de biogás de 0,003 m3 até os 130 dias de operação. Conclui-se que dejetos de suínos com 100 kg que receberam níveis de EL de 2540, 2620 e 2700 kcal kg-1 resultam em maior rendimento de biogás de 2,100; 1,613 e 1,468 m3 kg-1de SV adicionados. Os níveis de 2300 a 2700 kcal kg-1 para suínos em crescimento e terminação não oferecem riscos de falência do processo de digestão anaeróbia.

The main goal of this project was to assess the anaerobic digestion process using swine manure from growing and finishing phase fed diet with different levels of 2300, 2380; 2460; 2540; 2620 and 2700 kg kcal-1 net energy and also to estimate the chemicals parameters of effluents, total biogas production and biogas yield of manure from animals with different live body weight (50, 70 e 100 kg). The trial was carried out in the Laboratory of Animal Waste at the State University of Mato Grosso do Sul. It was assessed TS (Total solids), VS (Volatile solids), SS (Suspended solids), hydrogenionic potential (pH), Total nitrogen (Total N) and Total phosphorous (Total P). The essay of anaerobic digestion was carried out for 130 days in which 40 days comprise the start-up phase and 90 days of daily feeding. 12 semi-continuous digesters with capacity of 7.5 liters were used. Week analysis of the substrate and effluent of the digester were performed, it was measured: pH, ammonia nitrogen (TAN), parcial (PA), intermediate (IA) and total alkalinity (TA), and the amount of TS, VS and SS, biogas production (m3) and biogas yield (m3 kg-1). To assess Total N and Total P, biweekly analyses were performed. The data of TS, VS, FS were submitted to completely randomized design, in which the body weight were separately assessed, with six treatments and four replication; and the data of biogas yield of added VS were submitted to randomized complete block design in which the weeks were considered as cofactor, with six treatments and four blocks. The data was also evaluates individually by mean body weight (50, 70 and 100 kg of live body weight). The mean values were assessed through Scott-Knott test at 5% of probability. The different levels of net energy (2300 and 2700 kg-1) showed influence in the qualitative characteristics of the manure in terms of TS, VS and SS. For Total N and Total P of the manure, animals with live body weight nearly to 100 kg had higher values of 0.81 and 1.88%, respectively. When it comes to monitoring parameters (pH, N ammonia and alkalinity) all of them were satisfactory to the process of anaerobic digestion. The amount of TS, VS and SS of the substrates and effluent indicated that there was anaerobic degradation of the organic matter fraction throughout the process. After 98 days all treatments kept alike biogas production of 0.003 m3 until the day 130. We conclude that swine (of 100kg live body weight) manure from the phase of growing and finishing from pigs that had net energy in the diet of 2540, 2620 and 2700 kcal kg-1 can yield higher biogas production of 2.100; 1.613 e 1.468 m3 kg-1 of VS added. The different levels of net energy do not offer ricks to the anaerobic digestion process.

Efeito da adição de fibras de cana-de-açúcar pré-tratadas na produção de metano advinda da biodigestão anaeróbia de gorduras do leite

A digestão anaeróbia é uma alternativa para o tratamento de resíduos com altas concentrações de matéria orgânica. Por meio dos processos anaeróbios é possível a produção de biogás, fonte de energia renovável e ambientalmente amigável. Elevadas concentrações de lipídios, todavia, apesar de representarem elevado potencial metanogênico, interferem negativamente nos sistemas de tratamento, podendo inibir a atividade microbiana e, consequentemente, a produção de metano. O presente projeto avaliou o efeito da adição de bagaço de cana-de-açúcar no processo de biodigestão anaeróbia de elevadas concentrações de gorduras advindas de efluentes de laticínio. Para tanto foi utilizado bagaço de cana-de-açúcar in natura e pré-tratadas pelos seguintes métodos: organossolve, hidrotérmico, explosão à vapor e ácido diluído. O uso desse material lignocelulósico teve o objetivo de controlar a inibição causada pelos produtos da hidrólise dos lipídios por meio de sua adsorção e, consequentemente, diminuição das concentrações de tais compostos no meio. Outra hipótese era que o bagaço de cana-de-açúcar pudessem agir como co-substrato no processo de biodigestão anaeróbia. Inicialmente realizaram-se ensaios de biodegradabilidade anaeróbia com concentrações crescentes de gordura, que resultaram em relação entre substrato e microrganismo 0,06, 0,1, 0,2, 0,4 e 0,6 g DQO/gSTV. O ensaio com concentração em que foi verificada a inibição severa (0,4 gDQO/gSTV) do processo foi repetido com adição das fibras tratadas e não tratadas. Aos dados de produção acumulada de metano ajustou-se modelo de Gompertz, e parâmetros cinéticos foram inferidos. O bagaço de cana-de-açúcar mostrou potencial como adsorvente de gordura, pois as produções metanogênicas foram superiores à condição inibida sem adição desse material. A adição de fibras pré-tratadas por método organossolve resultou nas maiores produções de metano.

Anaerobic digestion is an alternative for treating waste with high concentrations of organic matter. Through anaerobic processes biogas production is possible, which represents environmentally friendly renewable energy source. High lipid concentrations, however, although having high methanogenic potential, may negatively interfere with the treatment systems causing microbial activity inhibition and, consequently, depleting the production of methane. This project evaluated the effect of addition of cellulosic fibers in the anaerobic digestion process of high concentrations of fatty residues from dairy effluents. Therefore, sugarcane bagasse fibers were used in natura and pretreated by the following methods: organosolve, hydrothermal, steam explosion and dilute acid. The use of the fibers had the objective to control the inhibition caused by the products of the hydrolysis of lipids through adsorption and thus decrease the concentrations of such compounds in the medium. We also had the hypothesis that the cellulosic fibers could act as co-substrate in the anaerobic digestion process. Initially, anaerobic biodegradability tests were set with increasing concentrations of fatty residue, which resulted in relation entity substrate and microorganism of 0.057; 0.12; 0.24; 0.37 and 0.57 g COD / gSTV. The assay in which severe inhibition was verified (0.37 g COD/gSTV) was repeated with addition of treated and untreated fibers. The sugarcane bagasse showed potential as adsorbent because the methanogenic yields in the presence of the fibers were higher than the inhibited condition, without addition of that material. The addition of pretreated fibers by organosolv method resulted in higher methane production.

CO-DIGESTÃO DE DEJETOS DE VACAS LEITEIRAS E GLICERINA BRUTA

Este estudo foi conduzido com o objetivo de avaliar o efeito da glicerina bruta em codigestão com dejetos de vacas leiteiras, sobre as produções de biogás, metano e redução de constituintes sólidos. No primeiro ensaio foram utilizados biodigestores do tipo semi-contínuos e no segundo ensaio biodigestores tipo batelada. O delineamento experimental utilizado no primeiro ensaio foi o inteiramente casualizado, em esquema fatorial 3x3, sendo três tempos de retenção hidráulica (TRH - 10, 17 e 24 dias) e três doses de glicerina bruta (0, 5 e 10 % dos sólidos totais - ST), adotando-se o período de acompanhamento dos biodigestores como subparcelas (cinco semanas). O delineamento experimental utilizado no segundo ensaio foi o inteiramente casualizado, utilizando-se cinco doses de glicerina bruta (0, 5, 10, 15 e 20 % dos ST) e cinco repetições. Em biodigestores semi-contínuos, as maiores reduções de ST e sólidos voláteis (SV) foram de 38,4 e 40,2%, nas doses de 3,6 e 2,7 % dos ST de glicerina bruta, respectivamente. E nos biodigestores tipo batelada, as máximas reduções de ST e SV foram de 36,7 e 50,7 % nas doses de glicerina de 4,7 e 3,4 % dos ST, respectivamente. Os potenciais máximos de produção de metano por ST e SV adicionados encontrados no sistema semi-contínuos foram de 1,4 e 1,8 l/g, nas doses de glicerina bruta de 3,0 e 3,3 %, respectivamente, o que corresponde a um incremento de, aproximadamente, 190 e 160% em relação ao controle. No sistema batelada, para os mesmo parâmetros, os valores máximos foram de 0,19 e 0,26 l/g, nas doses de 7,8 e 5,8 % dos ST, respectivamente, o que corresponde em aumento de 11 e 8% em relação ao tratamento sem adição de glicerina bruta. Conclui-se que a inclusão de glicerina bruta nas doses entre 2 e 4 % dos ST, foi melhor para todos os parâmetros avaliados no sistema semi-contínuos. E doses de glicerina bruta entre 5 e 8 % dos ST, foram melhores para potencializar a produção de biogás e metano no sistema batelada.

This study was conducted to evaluate the effect of crude glycerin in co-digestion with dairy cows manure, on biogas production, methane and reduction of solid constituents. In the first experiment were used semi-continuous digesters and the second experiment batch digesters type. The experimental design used in the first experiment was a completely randomized factorial 3x3, three hydraulic retention times (HRT- 10, 17 and 24 days) and three crude glycerin rates (0, 5 and 10% of the total solids - TS), adopting the follow-up period of biodigesters as subparcels (five weeks). The experimental design used in the second experiment was randomized using crude glycerin five doses (0, 5, 10, 15 and 20% of TS) and five repetitions. In semi-continuous digesters, the largest reductions of TS and volatile solids (VS) were 38.4 and 40.2% at doses of 3.6 and 2.7% of crude glycerin TS, respectively. Moreover, in the batch digesters reductions of TS and VS were 36.7 and 50.7% in doses of glycerine 4.7 and 3.4% of TS,respectively. The maximum potential methane production by TS and VS added, found in a semi-continuous system, were 1.4 and 1.8 l/g, in crude glycerin doses of 3.0 and 3.3%, respectively. It corresponds an increase of approximately 190 and 160% compared to control. In the batch system for the same parameters, the maximum values were of 0.19 and 0.26 l/g, at doses of 7.8 and 5.8% TS, respectively, which corresponds into increased 11 and 8% compared to the treatment without addition of crude glycerin.That inclusion of crude glycerin in doses between 2 and 4% TS were better for all parameters assessed in semi-continuous system. And crude glycerin doses between 5 and 8% of the TS, were better to enhance the production of biogas and methane in the batch system.