ABSTRACT

Recent studies point out losses of 30–40% of the produced methane in the effluent of anaerobic reactors treating sewage, reducing the renewable energy potential and the environmental footprint. A novel bench-scale upflow anaerobic hybrid (UAHB) reactor combining a sludge blanket at the bottom and a filter media at the top, both with three-phase separators, was proposed to evaluate the recovery of dissolved methane. UAHB was operated with volumetric organic loading rate of 1.24 kg COD m⁻³ d⁻¹ and hydraulic retention time of 8 h for 218 days to evaluate the influence of temperature (18°C, 23°C, and 28°C) in the methane dissolved in the effluent and collected from three-phase separators. Chemical oxygen demand (COD) and total suspended solids (TSS) removals efficiencies remained constant during the operation and equal to 90 and 95%, respectively, related to the activity of biomass retained in the filter media. Temperature increase influenced more the methane production in the sludge blanket rather than in the upper bed. The volume of recovered methane increased about 20% with the installation of the support media and the upper three-phase separator (3PHS). The loss of methane dissolved in the effluent was strongly influenced by the temperature, and higher with the decrease of this parameter. Non-statistically significant correlations were observed between the temperature and the methane production in the upper bed (p-value = 0.0943) and total (p-value = 0.0930). Thus, it can be concluded that the evaluated temperatures did not influence the global efficiency and the total methane yield of the UAHB reactor.

摘要

最近的研究指出，在处理污水的厌氧反应器的流出物中，产生的甲烷损失了 30-40%，从而降低了可再生能源的潜力和环境足迹。提出了一种新型的实验室规模上流式厌氧混合 (UAHB) 反应器，结合了底部的污泥床和顶部的过滤介质，均配有三相分离器，用于评估溶解甲烷的回收率。UAHB 以 1.24 kg COD m ⁻³  d ^{−1的体积有机负荷率运行}水力停留时间为 8 小时，持续 218 天，以评估温度（18°C、23°C 和 28°C）对溶解在流出物中并从三相分离器收集的甲烷的影响。化学需氧量 (COD) 和总悬浮固体 (TSS) 去除效率在运行期间保持不变，分别等于 90% 和 95%，这与保留在过滤介质中的生物质的活性有关。温度升高对污泥层中甲烷产生的影响比上层床更多。安装支撑介质和上部三相分离器 (3PHS) 后，回收的甲烷体积增加了约 20%。溶解在流出物中的甲烷的损失受温度的强烈影响，并且随着该参数的降低而增加。p值 = 0.0943) 和总计 ( p值 = 0.0930)。因此，可以得出结论，评估的温度不会影响 UAHB 反应器的整体效率和总甲烷产量。