Monti Matilde, Scoma Alberto, Martinez Gonzalo, Bertin Lorenzo, Fava Fabio
Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, via Terracini 28, 40131 Bologna, Italy.
Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, via Terracini 28, 40131 Bologna, Italy.
N Biotechnol. 2015 May 25;32(3):341-6. doi: 10.1016/j.nbt.2014.08.002. Epub 2014 Aug 29.
Among agro-wastes, olive mill wastewater (OMW) truly qualifies as a high impact organic residue due to its biochemical-rich composition and high annual production. In the present investigation, dephenolized OMW (OMWdeph) was employed as the feedstock for a biotechnological two-stage anaerobic process dedicated to the production of biohydrogen and volatile fatty acids (VFAs), respectively. To this end, two identically configured packed-bed biofilm reactors were operated sequentially. In the first, the hydraulic retention time was set to 1 day, whereas in the second it was equal to 5 days. The rationale was to decouple the hydrolysis of the organic macronutrients held by the OMWdeph, so as to quantitatively generate a biogas enriched in H2 (first stage aim), for the acidogenesis of the residual components left after hydrolysis, to then produce a highly concentrated mixture of VFAs (second stage aim). Results showed that the generation of H2 and VFAs was effectively split, with carbohydrates and lipids, respectively, being the main substrates of the two processes. About 250 ml H2 L(-1) day(-1) was produced, corresponding to a yield of 0.36 mol mol(-1) of consumed carbohydrates (expressed as glucose equivalents). The overall concentration of VFAs in the acidogenic process was 13.80 g COD L(-1), so that 2.76 g COD L(-1) day(-1) was obtained. Second generation biorefineries use a selected fraction of an organic waste to conduct a microbiologically-driven pathway towards the generation of one target molecule. With the proposed approach, a greater value of the waste was attained, since the multi-purpose two-stage process did not entail competition for substrates between the first and the second steps.
在农业废弃物中，由于其富含生化成分且年产量高，橄榄榨油废水（OMW）确实可被视为一种具有高影响力的有机残留物。在本研究中，脱酚后的OMW（OMWdeph）被用作一种生物技术两段厌氧工艺的原料，该工艺分别致力于生物制氢和挥发性脂肪酸（VFAs）的生产。为此，两个配置相同的填充床生物膜反应器依次运行。在第一个反应器中，水力停留时间设定为1天，而在第二个反应器中，水力停留时间等于5天。这样做的目的是将OMWdeph中所含有机大量营养素的水解过程解耦，以便定量生成富含氢气的沼气（第一阶段目标），用于水解后残留成分的产酸过程，进而生产出高浓度的VFAs混合物（第二阶段目标）。结果表明，氢气和VFAs的生成有效地分开了，碳水化合物和脂质分别是这两个过程的主要底物。产生了约250 ml H2 L(-1) day(-1)，对应于0.36 mol mol(-1)消耗碳水化合物（以葡萄糖当量表示）的产率。产酸过程中VFAs的总浓度为13.80 g COD L(-1)，因此获得了2.76 g COD L(-1) day(-1)。第二代生物精炼厂使用有机废弃物的选定部分，通过微生物驱动的途径生成一种目标分子。采用所提出的方法，废弃物的价值得到了更大提升，因为这种多用途的两段工艺在第一步和第二步之间不存在底物竞争。
