The objective of this research was to evaluate the distribution of the molecular weights of the recalcitrant organic matter contained in kraft mill effluents and identify microbial consortia responsible for an anaerobic biodegradable fraction. As a result, the average removal efficiencies of chemical organic demand (COD) and biological oxygen demand (BOD5) during the entire period of operation were 28% and 53%, respectively. The non-biodegradable organic matter was detected at molecular weights less than 1000 Da. However, most of the organic matter was in the molecular weight fraction higher than 10000 Da with 32 ± 11.6% COD as well as color (42.3 ± 8.7%), total phenolic compounds (35.9 ± 7.9%) and adsorbable organic compounds (AOX) (13.0 ± 2.7%). Methanogenic acetoclastic archaea of the genera Methanomethylovorans and Methanosarcina were found in the surface and middle zones of the reactor. Moreover, Methanosaeta and Methanolinea were identified in the low zone of the reactor. In all zones of the reactor, Desulfomicrobium and Desulfovibrio were found to be the most dominant genera of sulfate-reducing bacteria (SRB).

中文翻译：

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牛皮纸制浆废水中难降解有机物的分子量分布以及负责厌氧生物降解级分的微生物群落的鉴定。

这项研究的目的是评估牛皮纸厂废水中难降解有机物分子量的分布，并确定负责厌氧生物降解级分的微生物聚生体。结果，在整个操作期间，化学有机需量（COD）和生物需氧量（BOD5）的平均去除效率分别为28％和53％。检测到分子量小于1000 Da的不可生物降解的有机物。但是，大多数有机物的分子量分数高于10000 Da，COD为32±11.6％，并且颜色（42.3±8.7％），总酚类化合物（35.9±7.9％）和可吸附有机化合物（AOX） （13.0±2.7％）。Methanomethylovorans和Methanosarcina属的产甲烷菌破碎古菌被发现在反应堆的表面和中间区域。此外，在反应器的低区发现了甲烷菌和甲醇。在反应器的所有区域中，发现脱硫微生物和脱硫弧菌是减少硫酸盐的细菌（SRB）的最主要属。