RESUMO
ABSTRACT: The objective of this study was to evaluate the effects of the addition of sugarcane juice on the population dynamics of Escherichia coli and the presence of Shiga-toxigenic E. coli (STEC) during the anaerobic codigestion of dairy cattle manure. For the overall analyses at the end of a hydraulic retention time of 90 days, ten two-liter batch-type biodigesters were divided into two treatment groups: biodigester containing manure and water (MW) and the biodigester containing manure, water and sugarcane juice (MSC). For monitoring the population dynamics and presence of microorganisms, pH, and volatile acidity, tests were carried out every ten days, on 36 smaller-scale batch biodigesters made of one-liter plastic bottles (18 for each treatment). The reductions in E. coli population over time were significant in the MW (60 days) and MSC (20 days) biodigesters. Inactivation of STEC occurred in a shorter period (40 days in MW and <10 days in MSC). Significant differences were obtained between the two treatments, with the pH values being lower, the concentrations of volatile acids (VA) being higher, and the inactivation of E. coli and STEC being faster in the biodigester with sugarcane juice added. The amount of sugarcane juice applied (7%) suggests its suitability for the sanitization of dairy cattle manure for use as a biofertilizer, given the high reduction in the E. coli population and inactivation of STEC.
RESUMO: O estudo teve como objetivo avaliar o efeito da adição de caldo de cana-de-açúcar sobre a dinâmica da população de Escherichia coli e presença de E. coli shigatogixênicas (STEC) no processo de codigestão anaeróbia de dejetos de bovinos leiteiros. Foram utilizados dez biodigestores bateladas divididos em dois tratamentos, dejeto sem caldo de cana-de-açúcar (DSC) e dejeto com caldo (DCC), com tempo de retenção hidráulica (TRH) de 90 dias. Para o monitoramento periódico da dinâmica da população E. coli e presença de E. coli shigatoxigenicas, do pH e da acidez volátil, realizados a cada dez dias, foram abastecidos mais 36 biodigestores bateladas, construídos de garrafas de material plástico de um litro, sendo 18 unidades para cada tratamento. A redução das populações de E. coli no decorrer do tempo foi significativa no DSC (60 dias) e no DCC (20 dias). A inativação de E. coli shigatoxigênicas ocorreu em um período mais curto, 40 dias no DSC e menos de 10 dias no DCC. Foram obtidas diferenças significativas entre os tratamentos para os valores de pH, que foram menores, e as concentrações de ácidos voláteis, que foram maiores, com adição de caldo e contribuíram para a inativação mais rápida da E. coli e STEC. A dose de caldo de cana-de-açúcar utilizada (7%) sugere a adequada sanitização do dejeto bovino leiteiro, tendo em vista a alta redução na população de E. coli e a inativação de STEC.
RESUMO
The objective of this study was to evaluate the effects of the addition of sugarcane juice on the population dynamics of Escherichia coli and the presence of Shiga-toxigenic E. coli (STEC) during the anaerobic codigestion of dairy cattle manure. For the overall analyses at the end of a hydraulic retention time of 90 days, ten two-liter batch-type biodigesters were divided into two treatment groups: biodigester containing manure and water (MW) and the biodigester containing manure, water and sugarcane juice (MSC). For monitoring the population dynamics and presence of microorganisms, pH, and volatile acidity, tests were carried out every ten days, on 36 smaller-scale batch biodigesters made of one-liter plastic bottles (18 for each treatment). The reductions in E. coli population over time were significant in the MW (60 days) and MSC (20 days) biodigesters. Inactivation of STEC occurred in a shorter period (40 days in MW and 10 days in MSC). Significant differences were obtained between the two treatments, with the pH values being lower, the concentrations of volatile acids (VA) being higher, and the inactivation of E. coli and STEC being faster in the biodigester with sugarcane juice added. The amount of sugarcane juice applied (7%) suggests its suitability for the sanitization of dairy cattle manure for use as a biofertilizer, given the high reduction in the E. coli population and inactivation of STEC.
O estudo teve como objetivo avaliar o efeito da adição de caldo de cana-de-açúcar sobre a dinâmica da população de Escherichia coli e presença de E. coli shigatogixênicas (STEC) no processo de codigestão anaeróbia de dejetos de bovinos leiteiros. Foram utilizados dez biodigestores bateladas divididos em dois tratamentos, dejeto sem caldo de cana-de-açúcar (DSC) e dejeto com caldo (DCC), com tempo de retenção hidráulica (TRH) de 90 dias. Para o monitoramento periódico da dinâmica da população E. coli e presença de E. coli shigatoxigenicas, do pH e da acidez volátil, realizados a cada dez dias, foram abastecidos mais 36 biodigestores bateladas, construídos de garrafas de material plástico de um litro, sendo 18 unidades para cada tratamento. A redução das populações de E. coli no decorrer do tempo foi significativa no DSC (60 dias) e no DCC (20 dias). A inativação de E. coli shigatoxigênicas ocorreu em um período mais curto, 40 dias no DSC e menos de 10 dias no DCC. Foram obtidas diferenças significativas entre os tratamentos para os valores de pH, que foram menores, e as concentrações de ácidos voláteis, que foram maiores, com adição de caldo e contribuíram para a inativação mais rápida da E. coli e STEC. A dose de caldo de cana-de-açúcar utilizada (7%) sugere a adequada sanitização do dejeto bovino leiteiro, tendo em vista a alta redução na população de E. coli e a inativação de STEC.
Assuntos
Escherichia coli , Escherichia coli Shiga Toxigênica , Resíduos de Alimentos , Saccharum , Digestão Anaeróbia , Processamento de Resíduos SólidosRESUMO
The objective of this study was to evaluate the effects of the addition of sugarcane juice on the population dynamics of Escherichia coli and the presence of Shiga-toxigenic E. coli (STEC) during the anaerobic codigestion of dairy cattle manure. For the overall analyses at the end of a hydraulic retention time of 90 days, ten two-liter batch-type biodigesters were divided into two treatment groups: biodigester containing manure and water (MW) and the biodigester containing manure, water and sugarcane juice (MSC). For monitoring the population dynamics and presence of microorganisms, pH, and volatile acidity, tests were carried out every ten days, on 36 smaller-scale batch biodigesters made of one-liter plastic bottles (18 for each treatment). The reductions in E. coli population over time were significant in the MW (60 days) and MSC (20 days) biodigesters. Inactivation of STEC occurred in a shorter period (40 days in MW and 10 days in MSC). Significant differences were obtained between the two treatments, with the pH values being lower, the concentrations of volatile acids (VA) being higher, and the inactivation of E. coli and STEC being faster in the biodigester with sugarcane juice added. The amount of sugarcane juice applied (7%) suggests its suitability for the sanitization of dairy cattle manure for use as a biofertilizer, given the high reduction in the E. coli population and inactivation of STEC.(AU)
O estudo teve como objetivo avaliar o efeito da adição de caldo de cana-de-açúcar sobre a dinâmica da população de Escherichia coli e presença de E. coli shigatogixênicas (STEC) no processo de codigestão anaeróbia de dejetos de bovinos leiteiros. Foram utilizados dez biodigestores bateladas divididos em dois tratamentos, dejeto sem caldo de cana-de-açúcar (DSC) e dejeto com caldo (DCC), com tempo de retenção hidráulica (TRH) de 90 dias. Para o monitoramento periódico da dinâmica da população E. coli e presença de E. coli shigatoxigenicas, do pH e da acidez volátil, realizados a cada dez dias, foram abastecidos mais 36 biodigestores bateladas, construídos de garrafas de material plástico de um litro, sendo 18 unidades para cada tratamento. A redução das populações de E. coli no decorrer do tempo foi significativa no DSC (60 dias) e no DCC (20 dias). A inativação de E. coli shigatoxigênicas ocorreu em um período mais curto, 40 dias no DSC e menos de 10 dias no DCC. Foram obtidas diferenças significativas entre os tratamentos para os valores de pH, que foram menores, e as concentrações de ácidos voláteis, que foram maiores, com adição de caldo e contribuíram para a inativação mais rápida da E. coli e STEC. A dose de caldo de cana-de-açúcar utilizada (7%) sugere a adequada sanitização do dejeto bovino leiteiro, tendo em vista a alta redução na população de E. coli e a inativação de STEC.(AU)
Assuntos
Saccharum , Escherichia coli , Escherichia coli Shiga Toxigênica , Resíduos de Alimentos , Digestão Anaeróbia , Processamento de Resíduos SólidosRESUMO
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)
Assuntos
Suínos , Esterco , Matéria Orgânica , Gases , Efeito Estufa , Digestão Anaeróbia , Compostagem , Nitrificação , DesnitrificaçãoRESUMO
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.