Dionisi D, Renzi V, Majone M, Beccari M, Ramadori R
Department of Chemistry, University of Rome "La Sapienza", P.le Aldo Moro 5, Rome 00185, Italy.
Water Res. 2004 Apr;38(8):2196-206. doi: 10.1016/j.watres.2004.01.018.
In spite of the fact that in most activated sludge plants substrate complex mixtures are removed under alternating anoxic and aerobic conditions, most studies on the dynamic response of biomass are limited to feeding a single substrate (acetate or glucose) under a single redox condition (aerobic or anoxic). In this study, the dynamic response of biomass in a sequencing batch reactor is described in terms of substrate removal and related storage as internal polymers, as functions of single or simultaneous feed of several substrates (acetate, glucose, glutamic acid and ethanol) and of anoxic vs. aerobic conditions. Under anoxic conditions, the four substrates were simultaneously removed at a significantly greater nitrate removal rate than when single substrates were present, so showing that the simultaneous removal was partially due to independent metabolic activities. On the other hand, the removal of every substrate was affected (positively or negatively) by the presence of the others, demonstrating that the substrates can be also used by the same metabolism. As an exception, acetate removal was not affected by the presence of other substrates. As for the comparison of aerobic and anoxic conditions, the acetate uptake rate almost doubled moving from anoxic to aerobic conditions, whereas other substrates were only slightly affected. This difference was probably due to the additional presence of aerobic denitrification, which was much more important for acetate. This also confirmed that acetate removal was independent from other substrates. In all cases, storage was the main mechanism of solids formation, so confirming the general importance of such phenomenon under dynamic conditions, independently from feed complexity and redox conditions.
尽管在大多数活性污泥处理厂中，复杂的底物混合物是在缺氧和好氧交替条件下去除的，但大多数关于生物质动态响应的研究仅限于在单一氧化还原条件（好氧或缺氧）下投喂单一底物（乙酸盐或葡萄糖）。在本研究中，描述了序批式反应器中生物质的动态响应，该响应以底物去除和作为内部聚合物的相关储存为指标，是几种底物（乙酸盐、葡萄糖、谷氨酸和乙醇）单一或同时投喂以及缺氧与好氧条件的函数。在缺氧条件下，四种底物同时被去除，硝酸盐去除率显著高于存在单一底物时，这表明同时去除部分归因于独立代谢活动。另一方面，每种底物的去除都受到其他底物存在的影响（正向或负向），这表明底物也可被相同代谢利用。作为例外，乙酸盐的去除不受其他底物存在的影响。至于好氧和缺氧条件的比较，从缺氧条件转变为好氧条件时，乙酸盐摄取率几乎翻倍，而其他底物仅受到轻微影响。这种差异可能是由于额外存在的好氧反硝化作用，这对乙酸盐更为重要。这也证实了乙酸盐的去除独立于其他底物。在所有情况下，储存都是固体形成的主要机制，因此证实了该现象在动态条件下的普遍重要性，与进料复杂性和氧化还原条件无关。
