ABSTRACT
O presente estudo avaliou as condições operacionais que podem maximizar a produção do biogás a partir do uso de biodigestores. Os ensaios experimentais foram conduzidos utilizando dejetos de suínos em fase de terminação, com concentração de sólidos totais na coleta de 70,6% p/v. Os experimentos avaliaram, segundo a metodologia de superfície de resposta (MSR), a influência de cinco fatores: temperatura, concentração inicial de matéria orgânica e influência da adição de nutrientes inorgânicos (FeSO4×7H2O, NiSO4×6H2O e MnSO4×4H2O). Os melhores resultados foram obtidos para a concentração de biomassa inicial de 395 a 595 g.L-1 e a temperatura de 33,5 a 44ºC. Em relação ao uso de nutrientes no processo de biodigestão anaeróbia, os resultados permitiram concluir que houve significativa redução no tempo de retenção hidráulica (TRH) e maior produtividade de biogás.
This study evaluated the operational conditions that maximize the production of biogas from the use of digesters. Experimental tests were conducted using termination phase swine wastes, with total solids in collecting 70.6% w/v. The experiments evaluated according to the response surface methodology (RSM), the influence of five factors: temperature, initial concentration of organic matter and influence of inorganic nutrients addition (FeSO4×7H2O, NiSO4×6H2O and MnSO4×4H2O). Better results were obtained for the initial concentration biomass of 395 to 595 g.L-1 and temperatures from 33.5 to 44ºC. Regarding the use of nutrients in the anaerobic digestion process, the results showed that there was significant reduction in hydraulic retention time and increased biogas productivity.
ABSTRACT
A solvothermal method was used to prepare zinc ferrite spinel oxide (ZnFe2O4) using ethylene glycol and 1,4 butanediol as solvent diols, and the influence of diols on the physical properties of ZnFe2O4 particles was investigated. The produced particles were characterized by X-ray powder diffraction (XRD), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption isotherms, and the catalytic activity for the organic pollutant decomposition by heterogeneous photo-Fenton reaction was investigated. Both solvents produced particles with cubic spinel structure. Microporous and mesoporous structures were obtained when ethylene glycol and 1,4 butanediol were used as diols, respectively. A higher pore volume and surface area, as well as a higher catalytic activity for the pollutant degradation were found when 1,4 butanediol was used as solvent.
