Marco Antonio Previdelli Orrico Junior

Adição de óleo e lipase sobre a biodigestão anaeróbia de dejetos suínos

The goal this paper was to verify the efficiency of the anaerobic co-digestion of manure with increasing levels of added oil disposal and lipase. Were tested four levels oil (8, 12, 16 and 20 g kg-1 substrate) and 3 doses of lipase (1, 2, 3g-1 kg of substrate). The parameters evaluated were: reduction of total solids (TS), volatile solids (VS) and most probable number (MPN) of total coliforms (TC) and thermophilic (TTC), in addition to pH, chemical oxygen demand (COD), production and potential biogas production. The results demonstrated the influence of additions of oil and lipase to the reductions in SV and ST effluent pH, following a model of linear prediction and descending. The reductions in MPN of TC and TTC were higher in treatments with more adding oil and lipase. Biogas production showed a negative correlation with the additions of lipase, and these yielded linear effect on the potential of biogas/kg of manure, ST and SV added. The additions of oil and lipase did not provide favorable effects on biogas production.

Biodigestão anaeróbia de dejetos de poedeiras coletados após diferentes períodos de acúmulo

The objective was to evaluate the interference of the time of accumulation of waste on the performance of the anaerobic digestion process of waste from laying hens. The experiment was conducted in a completely randomized design with four treatments, which observed 1, 8, 15 and 22 days of accumulated waste with five repetitions per treatment, with a total of 20 digesters. It was used batch digesters of bench with useful capacity of 3 liters of substrate fermentation. The efficiency of digestion was evaluated by reductions in total solids (TS), volatile solids (VS), most probable number (MPN) of total and thermotolerant coliforms, beyond the production and potential of biogas production. There were significant reductions in the levels of VS present in the laying hens waste as it increased the days of accumulation, being observed a level of VS (in percent of TS) of 97.1 and 75.6% of VS for 1 and 22 days of accumulation, respectively. The reduction in VS contributed to reduce the production and potential of biogas production as it increased the days of accumulation, and observed a 37.2% of reduction in the potential production of biogas kg VS-1 between the lowest and longer period of accumulation, or 6.81 liters less per day accumulation for each kg of VS added. It was also observed reductions of 100% in the MPN of total and thermotolerant coliforms at the end of the process, independent of the tested treatment. The storage time reduces the potential production of biogas from manure layers.

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

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

O objetivo foi avaliar o desempenho da co-digestao anaerobia de dejetos de suinos associados com crescentes doses de glicerina bruta, adotando-se diferentes tempos de retencao hidraulica (TRH). O delineamento utilizado foi inteiramente casualizado em esquema fatorial 3x4, tres TRH (10; 17 e 24 dias) e quatro doses de glicerina bruta (0; 5; 10 e 15% dos solidos totais), com quatro repeticoes por tratamento. Os parâmetros avaliados foram producao e potencial de producao de biogas, reducoes de solidos totais (ST), fibra em detergente neutro (FDN) e fibra em detergente acido (FDA). A producao de biogas e potencial de producao apresentaram efeito quadratico nos TRH de 17 e 24 dias, evidenciando como doses ideais 4,09 e 5,63% de glicerina bruta, respectivamente, para producao e 4,52 e 5,42% de glicerina bruta para potencial de producao. Nao houve diferenca entre as doses de glicerina bruta dentro do TRH de 10 dias para as reducoes de ST. No entanto, foi observado diferenca entre as doses nos TRH 17 e 24, com a maior reducao observada de 54,9% ao incluir 5% de glicerina bruta no maior TRH. As reducoes de FDN e FDA aumentaram de acordo com a adicao de glicerina bruta nos TRHs de 10 e 17 dias. A inclusao de 4 a 6% de glicerina bruta no TRH 24 mostrou-se mais eficiente na producao de biogas e reducoes de ST e FDN. Ja visando maior reducao de FDA pode-se utilizar doses mais altas de glicerina a partir da co-digestao com dejetos suinos.