Co-digestion of swine excreta associated with increasing levels of crude glycerin

ABSTRACT The objective of this research was to evaluate the performance of anaerobic co-digestion of swine excreta associated with increasing doses of crude glycerin and different hydraulic retention times (HRT). A completely randomized design was adopted in a 3 × 4 factorial arrangement composed of three HRT (10, 17, and 24 days) and four crude glycerin doses (0, 5, 10, and 15 g/100 g of total solids [TS]), with four replications per treatment. The assessed parameters were: biogas production potential, reductions of volatile solids (VS), chemical oxygen demand (COD), and most probable number of total and thermotolerant coliforms. The biogas production per added VS presented quadratic effect at 17 and 24 days of HRT, with ideal doses of 5.5 and 5.9 g of crude glycerin/100 g TS, respectively. There was no difference among glycerin doses at 10-day HRT for VS reductions; however, at HRT of 17 and 24 days, there were differences, with greater reduction of 61.1% for 5 g of crude glycerin/100 g TS at 24-day HRT. The COD reduction values showed an effect among retention times, in which the 24-day HRT provided the best results. Reductions in coliforms were greater than 99%, with no difference among treatments. Addition of 5 to 6 g of crude glycerin/100 g TS with a 24-day HRT is more effective in biogas production and reduction of VS, COD, and coliforms from co-digestion of swine excreta

Desempenho da co-digestão anaeróbia de dejetos suínos com inclusão de glicerina bruta

RESUMO O objetivo foi avaliar o desempenho da co-digestão anaeróbia de dejetos de suínos associados com crescentes doses de glicerina bruta, adotando-se diferentes tempos de retenção hidráulica (TRH). O delineamento utilizado foi inteiramente casualizado em esquema fatorial 3x4, três TRH (10; 17 e 24 dias) e quatro doses de glicerina bruta (0; 5; 10 e 15% dos sólidos totais), com quatro repetições por tratamento. Os parâmetros avaliados foram produção e potencial de produção de biogás, reduções de sólidos totais (ST), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA). A produção de biogás e potencial de produção apresentaram efeito quadrático nos TRH de 17 e 24 dias, evidenciando como doses ideais 4,09 e 5,63% de glicerina bruta, respectivamente, para produção e 4,52 e 5,42% de glicerina bruta para potencial de produção. Não houve diferença entre as doses de glicerina bruta dentro do TRH de 10 dias para as reduções de ST. No entanto, foi observado diferença entre as doses nos TRH 17 e 24, com a maior redução observada de 54,9% ao incluir 5% de glicerina bruta no maior TRH. As reduções de FDN e FDA aumentaram de acordo com a adição de glicerina bruta nos TRHs de 10 e 17 dias. A inclusão de 4 a 6% de glicerina bruta no TRH 24 mostrou-se mais eficiente na produção de biogás e reduções de ST e FDN. Já visando maior redução de FDA pode-se utilizar doses mais altas de glicerina a partir da co-digestão com dejetos suínos

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

ABSTRACT: 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

The quality of crude glycerine influences the fermentation and nutritive value of Piatã grass silage

We aimed to evaluate the effects of crude glycerine purity and levels of glycerol on the fermentative profile, microorganisms counting, and nutritional value of Piatã grass silage. The experiment was carried out in a 3×3+1 completely randomized factorial design using three different types of crude glycerine [low purity (40% of glycerol), medium purity (60% glycerol), and high purity (80% glycerol)], three doses of glycerol (20, 40, and 60 g/kg DM), and a control (no crude glycerine added) as an additional treatment, which were stored for 80 days. Statistical differences were not observed on fermentative losses of the treatments tested. The increase of glycerol doses resulted in higher levels of non-fibrous carbohydrates and lower levels of fibre components. The addition of low-purity crude glycerine increased the levels of fat and in vitro digestibility of silages. The highest levels of lactic acid and acetic acid occurred in the treatments with 60 g/kg of glycerol when using crude glycerine with a low purity. The lowest lactic acid content was observed in the control treatment and in the lowest dose of glycerol. The highest glycerol dose (60 g/kg), associated with the lowest degree of crude glycerine purity (40%) resulted in the greatest nutritional value and provided the best silage conservatio

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

Jejum alimentar pré-abate no rendimento e qualidade de carcaça de frangos de corte tipo griller

O manejo pré-abate dos frangos é provavelmente uma das etapas da cadeia produtiva que exerce maior influência nos índices qualitativos e quantitativos dos produtos do abatedouro. O objetivo desta pesquisa foi avaliar os efeitos do período de jejum pré-abate sobre o rendimento de carcaça e cortes comerciais e parâmetros qualitativos da carne de frangos de corte tipo Griller. No 35º dia 10 aves por tratamento (4, 8, 13 e 17 horas de jejum pré-abate) foram abatidas e foram analisadas as variáveis: rendimentos da carcaça quente (RCQ) e fria (RCF), rendimento de cortes comerciais, capacidade de retenção (CRA) e absorção de água (CAA), perda por cozimento (PC) e perda de exsudato (PE). O peso vivo e de carcaça quente das aves submetidas a quatro horas de jejum foi superior ao das aves submetidas aos demais tempos de jejum. Entretanto, não houve diferença para o RCQ e RCF entre os tratamentos. As carcaças das aves submetidas aos maiores tempo de jejum apresentaram maior taxa de absorção de água pós-resfriamento. Não foram observadas diferenças significativas no rendimento de cortes e nos parâmetros qualitativos. A perda de peso vivo dos frangos antes do abate é diretamente proporcional ao período de jejum, refletindo-se sobre o peso da carcaça quente e fria, porém não no rendimento de carcaça e cortes e sem prejuízos aos atributos qualitativos da carne

Crude glycerin in co-composting with laying hen manure reduces N losses

The composting of laying hen manure is an efficient way of treating waste and producing an organic fertilizer with excellent characteristics; however, the high N losses reduce its concentration in the resulting fertilizer. Associating this residue with crude glycerin (CG) promotes a better C:N ratio and contributes to higher N retention during composting, with improvements in solids reduction and production of organic fertilizer with higher concentration of this nutrient. We carried out this research considering the hypothesis that adding CG – a byproduct of biodiesel production – to laying hen waste composting provides better N retention in the fertilizer generated. Increasing CG doses (0, 3, 6, 9, and 12 % in relation to the fresh mass in the windrows) were added to the laying hen manure with windrows composted for 70 days. A reduction by 100 % in total and thermotolerant coliforms occurred at all levels of CG addition. The maximum reductions in total (TS) and volatile (VS) solids were 64 and 76 %, respectively, and occurred with the addition of 6 % CG. The windrows that did not receive CG had higher N losses during the process (32 %) while the highest N concentration in the compost was 5 % at 6 % CG. We identified that adding 6 % CG to the laying hen manure in co-composting increases the reductions in TS and VS and provides higher N retention, which improves the quality of the organic fertilizer

Co-digestão anaeróbia de dejetos de suínos, níveis de inclusão de óleo de descarte e microrganismos lipolíticos redução do impacto ambiental

The objective of this work for evaluating the potential of biogas and methane productions and still and reductions in levels of total solids (TS), volatile solids (VS) and neutral detergent fiber (NDF) of the co-digestion anaerobic digestion in digesters fed with swine manure plus disposal of oil and lyophilized microorganisms. For assay development substrates were prepared containing 4% TS, consisting of swine manure, disposal oil (the proportions 8, 10 and 12% oil content in relation to the substrate TS), lyophilized microorganisms (Biol-2000 ® - concentrations of 10 g/m3 and 15 g/m3 ), water for dilution of this waste and inoculum for batch digesters supply. There was no significant difference with respect to reductions in TS, VS and NDF constituents, providing very significant reductions in average 54.14; 62.79 and 49.16% respectively. Regarding the potential of biogas production, the highest yields occurred in digesters supplied with 10% oil and 15 g/m3 of Biol®, being 0.43 and 0.54 L of biogas per kg of TS and VS added, respectively, similar results were found when assessed the potential for methane production, with higher values (0.22 and 0.27 L of methane per kg of TS added and VS, respectively) obitidos the same treatment. The inclusion of 15 g/m3 in Biol® substrate composition containing swine manure and 10% of oil improves the yields of biogas and methane.Objetivou-se com a execução deste trabalho avaliar as produções e potenciais de produção de biogás e metano e ainda as reduções dos teores de sólidos totais (ST), sólidos voláteis (SV) e fibra em detergente neutro (FDN) do processo de co-digestão anaeróbia em biodigestores alimentados com dejetos de suínos acrescidos de óleo de descarte e microrganismos liofilizados. Para desenvolvimento do ensaio foram preparados substratos contendo 4% de S T, compostos por dejetos de suínos, óleo de descarte (nas proporções 8, 10 e 12% de óleo em relação aos teores de ST do substrato), microrganismos liofilizados (Biol® - nas concentrações de 10g/m3 e 15g/m3 ), água para diluição destes resíduos e inóculo para abastecimento de biodigestores batelada. Não houve diferença significativa com relação às reduções dos constituintes ST, SV e FDN, apresentando reduções bastante significativas, em média de 54,14; 62,79 e 49,16%, respectivamente. Com relação aos potenciais de produção de biogás, as maiores produções ocorreram nos biodigestores abastecidos com 10% de óleo e 15g/m3 de Biol®, sendo 0,43 e 0,54 L de biogás por kg de ST e SV adicionados, respectivamente, resultado semelhante foi encontrado quando avaliado o potencial de produção de metano, sendo os maiores valores obtidos (0,22 e 0,27 L de metano por kg de ST e SV adicionados, respectivamente) obitidos pelo mesmo tratamento. A inclusão de 15g/m3 de Biol® na composição de substratos contendo dejetos de suínos e 10 % de óleo melhora os rendimentos de biogás e metano