Comparative process stability and efficiency of anaerobic digestion; mesophilic vs. thermophilic
Comparative process stability and efficiency of anaerobic digestion; mesophilic vs. thermophilic
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DOI：
10.1016/s0043-1354(02)00147-1
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发表时间：
2002-10-01
期刊：
影响因子：
12.8
通讯作者：
Speece, RE
中科院分区：
文献类型：
--
作者：
Kim, M;Ahn, YH;Speece, RE
采用四种不同的反应器配置，分别是：每日分批进料单级连续搅拌槽反应器（CSTR）、连续进料单级连续搅拌槽反应器（CSTR）、每日分批进料两相连续搅拌槽反应器（CSTR）和每日分批进料非混合单级反应器，对中温厌氧反应器（35℃）和亲热厌氧反应器（55℃）的工艺稳定性和效率进行了比较评价。结果讨论了三个阶段：(1)启动，(2)稳态，(3)有机负载率（OLR）增加，直到反应器失效（pH低于5.5）。在启动过程中，两种温度下单级cstr的稳定性最低，而非混合单级反应器在最短时间内达到稳定状态，pH相对稳定，挥发性脂肪酸（VFA）较低。在嗜热非混合反应器的情况下，丙酸盐的有效去除发生，但当VFA增加时，需要补充营养物质（Ca, Fe， Ni和Co）。结果表明无机养分生物利用度的重要性。反应器稳态性能的对比结果清楚地表明，亲热非混合反应器在VFA较低、产气量较高和挥发性固体去除率方面具有优越的性能，这意味着微生物群落的接近可以缓解亲热系统出水水质差的问题。在OLR增加至反应器失效的过程中，除亲热非混合反应器外，所有亲热反应器的丙酸浓度均随OLR的增加而增加，而除亲热两相体系外，所有亲热反应器的VFA浓度几乎没有增加。在相同条件下，随着OLR的增加，连续进料反应器的产气量最低，而非混合进料反应器在两种温度下的产气量最高。据推测，非混合反应器配置有更紧密的微生物财团接近比其他。因此，本研究结果表明了微生物群落接近性的重要性。提出的两种共生菌之间距离影响的模型与本研究的数据相匹配。(C) 2002 Elsevier Science Ltd.版权所有。
The comparative process stability and efficiency of mesophilic (35degreesC) and thermophilic anaerobic digestion (55degreesC) has been evaluated for four different reactor configurations, which are: daily batch-fed single-stage continuously stirred tank reactor (CSTR), continuously fed single-stage CSTR, daily batch-fed two-phase CSTR, and daily batch-fed non-mixed single-stage reactor. The results are discussed for three periods: (1) start-up, (2) steady state, and (3) organic loading rate (OLR) increase until reactor failure (pH below 5.5). During the start-up, the single-stage CSTRs at both temperatures showed the least stability, while the non-mixed single-stage reactors reached steady state in the shortest time with relatively stable pH and low volatile fatty acid (VFA). In the case of the thermophilic non-mixed reactor, efficient removal of propionate occurred but supplementation of nutrients (Ca, Fe, Ni, and Co) was required when VFA increased. The results imply the importance of inorganic nutrients bioavailability. The comparative results of the reactor performance at steady state clearly showed the superior performance of the thermophilic non-mixed reactor with respect to lower VFA, higher gas production and volatile solids removal implying that microbial consortia proximity can alleviate the problem of poor effluent quality in thermophilic system. During the OLR increase until reactor failure, all thermophilic reactors except the thermophilic non-mixed reactor showed increases in propionate concentrations as the OLR increased, while all mesophilic reactors except the mesophilic two-phase system showed little increase in VFA concentrations. When all reactors had the same conditions with OLR increase, the continuously fed reactors showed the lowest gas production, while the non-mixed reactors showed the highest gas production at both temperatures. It is hypothesized that the non-mixing reactor configuration has closer microbial consortia proximity than others. Therefore, the results in this study indicated the importance of microbial consortia proximity. A proposed model for the effect of the distance between two syntrophic bacteria reasonably matched the data in this study. (C) 2002 Elsevier Science Ltd. All rights reserved.