Aerobic storage by activated sludge on real wastewater
Aerobic storage by activated sludge on real wastewater
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DOI：
10.1016/s0043-1354(01)00108-7
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发表时间：
2001-11-01
期刊：
影响因子：
12.8
通讯作者：
Smurra, P
中科院分区：
文献类型：
--
作者：
Carucci, A;Dionisi, D;Smurra, P
活性污泥法通常在动态条件下运行，其中微生物的反应除了生长外，还包括几种去除COD的机制，特别是以聚合物的形式储存。虽然可以找到大量证据表明在动态条件下利用合成底物进行好氧储存(Majone等人，水科学。泰克诺。39(1)(1999)61)，关于用真实的活性污泥和废水去除COD的机理仍然知之甚少。因此，本论文的目的是给出真实污泥与进水废水混合时发生的储存现象的直接证据，以及它们在典型的呼吸批量测试中对我们的曲线的影响。为此，以乙酸盐、过滤废水和原废水为碳源，对同一污泥进行了呼吸计量法间歇试验，并测定了乙酸盐的吸收和储存聚合物的形成。结果表明，聚-3-羟基丁酸酯(PHB)的储存总是对醋酸盐的去除起主要作用，对于废水，PHB也是从其他基质中形成的。PHB的形成明显发生在高速率RBCOD阶段，但对于废水，它只占整个RBCOD去除的一小部分(18-22%)，因此在呼吸图的低速率SBCOD阶段，呼唤其他不明储存化合物或其他非储存现象，一旦醋酸盐耗尽，PHB显然被用于以醋酸盐作为内部储备材料的测试中。在对过滤废水和原废水的测试中，PHB浓度下降的速度要慢得多。可能是由于外部SBCOD(可溶的和不可溶的)的存在，形成了更多的PHB。更有甚者。据报道，过滤后或原水中SBCOD的含量远高于乙酸乙酯间歇试验中的含量，从而证实了外部SBCOD的主要贡献。然而，通过对过滤后的废水和未经处理的废水的测试进行比较，不能容易地区分先前存储的化合物和外部SBCOD的利用各自的贡献，因为在过滤后的废水的测试中也同时存在这两种底物。作为一个副作用，用于评估真可溶和可生物降解的COD的化学-物理方法往往高估了基于呼吸测量的RBCOD，至少对于被观察的废水是这样。即使由ASM3建模(Gujer等人，Water Set.泰克诺。39(1)(1999)183)使很好地描述整个实验行为成为可能，它要求形成比实验观察到的PHB多得多的存储化合物。为了确定ASM3的概念结构，这些化合物还有待鉴定和定量。(C)2001爱思唯尔科学有限公司。保留所有权利。
Activated sludge processes are often operated under dynamic conditions, where the microbial response can include, besides of growth, several COD removal mechanisms, and particularly the storage in form of polymers. While abundant evidence of aerobic storage under dynamic conditions with synthetic substrates can be found (Majone et al., Water Sci. Technol. 39(1) (1999) 61), there is still little knowledge about COD removal mechanisms with real activated Sludge and wastewater. The aim of the present paper is therefore to give a direct evidence of storage phenomena occurring when a real sludge is mixed with influent wastewater and of their influence onto OUR profiles in typical respirometric batch tests. For this purpose, respirometric batch tests were performed on the same sludge by using acetate, filtered wastewater and raw wastewater as carbon source along with determination of acetate uptake and storage polymer formation. Comparison of results obtained has shown that poly-3-hydroxybutyrate (PHB) storage gives always the main contribution to acetate removal and that in the case of wastewater PHB is also formed from other substrates. PHB formation clearly occurs during the high-rate RBCOD-phase, however for wastewater it accounts for only a fraction (18-22%) of overall RBCOD removal, so calling for other unidentified storage compounds or other non-storage phenomena, In the low-rate SBCOD phase of respirogram PHB is clearly utilised in tests with acetate as internal reserve material once the acetate is depleted. In tests with filtered and raw wastewater the PHB concentration decreases much slower. probably because more PHB is formed due to the availability of external SBCOD (soluble and not). Moreover. reported OUR in the SBCOD-phase from filtered or raw wastewater are quite higher than those reported in batch tests with acetate, so confirming a main contribution of external SBCOD. However, the respective contributions for utilisation of previously stored compounds and of external SBCOD cannot be easily separated by the comparison of tests on filtered and raw wastewater, because both substrates are simultaneously present also in tests with the filtered wastewater. As a side consequence, the chemical-physical method for evaluation of true soluble and biodegradable COD tends to overestimate the respirometry-based RBCOD, at least for the wastewater under observation. Even though modelling by ASM3 (Gujer et al., Water Set. Technol. 39(1) (1999) 183) makes it possible to well describe the whole experimental behaviour, it requires that much more storage compounds are formed than the experimentally observed PHB. These compounds have still to be identified and quantified in order to confirm the conceptual structure of ASM3. (C) 2001 Elsevier Science Ltd. All rights reserved.