Two-stage anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) was carried out: hydrolysis and acidogenesis in a continuous anaerobic hydrolytic leach bed (AHLB) reactor loaded at different rates (Bv = 3.8-7 gVSSL⁻¹d⁻¹) and methanogenesis of leachates, diluted with municipal wastewater in an upflow anaerobic sludge blanket (UASB) reactor at organic loading rates of 6.6-13 gCODLr⁻¹d⁻¹. In the AHLB reactor, 51-76% and 58-71% volatile solids and chemical oxygen demand (COD) removal efficiencies were obtained. During the hydrolysis and acidogenesis phases, the effluents were at pH 4.93, the leachate had a volatile fatty acids concentration of 35 g/L and the biogas was composed only of CO₂. The average methane production in the UASB in the load of 4.4 gVS L⁻¹ d⁻¹ in the AHLB was 3.32 LCH4Lr⁻¹d⁻¹ (yCH4 = 80%), with COD removal efficiency of 95% and methane yield 279 LCH4KgVS⁻¹OFMSW degraded.
The treatment of pool water, whether for recreational or sporting purposes, by phytoremediation is widely applied. This work evaluates two artificial vertical flow wetlands, one on a real scale and the other on a laboratory scale, which have been planted with Typha domingensis, for the treatment of pool water in the climatic conditions of the city of Santiago de Cuba. When the hydraulic load applied to the real scale wetland was less than 0.25 m3∙m–2∙d–1, the levels of organic and microbiological contamination in the pool were below the maximum limits allowed by Cuban standards. At a laboratory scale, the presence of vegetation favoured the elimination of nitrogen compounds (nitrates and ammonium) and organic materials (BOD and COD). This behaviour is explained by the presence of processes of assimilation of organic compounds, or by the action of microorganisms associated with the rhizome of plants, which establish a symbiotic mechanism favourable to phytodepuration. The minimum concentration of ammonium obtained in outflow from the laboratory-scale reactor without vegetation reached a value of 2.15 mg∙m–3, which is within the limits allowed by the sanitary regulations.
A simplex-lattice mixture design and the surface response methodology (SRM) were used to modeling the methane production on the anaerobic co-digestion (AcoD) of three different substrates generated from slaughterhouses: manures (Ms), solid organic wastes (SOW) and wastewaters (SHWW). In the first stage of the study, a characterization of these residuals was carried out; meanwhile, the mixture design was used in the second step to determine the methane production obtained on the AcoD of the substrates considered. The results of the analysis of RSM show that the best adjusted model was the special cubic, with high values of R 2 and R 2 adj of 95.13% and 90.96%, respectively. According to the statistical -mathematical model obtained in this study, wastes generated from slaughterhouses are appropriated material for acquire biogas; nonetheless, significant antagonistic effects was observed when increasing the amounts of SOW and SHWW, apparently by the increase in the levels of proteins and fat, oil and grease (FOGs). A good strategy to implement in order to achieve high methane productions for the effluent treatments from meat producing industries is a combination of substrates Ms and SOW; meanwhile, is preferable to separately treat the SHWW in high rate AD systems or anaerobic lagoons.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.