The anaerobic degradation of 2,4,6-trichlorophenol (246TCP) has been studied in batch experiments. Granular sludges previously acclimated to 2,4-dichlorophenol (24DCP) and then adapted to at a load of 330 μM 246TCPd(-1) in two expanded granular sludge bed (EGSB) reactors were used. One of the reactors had been bioaugmented with Desulfitobacterium strains whereas the other served as control. 246TCP was tested at concentrations between 250 and 760 μM. The study focused on the fate of both fermentation products and chlorophenols derived from dechlorination of 246TCP. This compound mainly affected the biodegradation of acetate and propionate, which were inhibited at 246TCP concentrations above 380 μM. Lactate and ethanol were also accumulated at 760 μM 246TCP. Methanogenesis was strongly inhibited at 246TCP concentrations higher than 380 μM. A diauxic production of methane was observed, which can be described by a kinetic model in which acetoclastic methanogenesis was inhibited, whereas hydrogenotrophic methanogenesis was hardly affected by 246TCP. The similarity of the kinetic parameters obtained for the control and the bioaugmented sludges (K(i)=175-200 μM 246TCP and n=7) suggests that methanogenesis is not affected by the bioaugmentation. Moreover, the 246TCP dechlorination occurred mainly at ortho position, successively generating 24DCP and 4-chlorophenol (4CP), which was identified as final product. The bioaugmentation does not significantly improve the anaerobic biodegradation of 246TCP. It has been shown that the active biomass is capable of bioaccumulating 246TCP and products from dechlorination, which are subsequently excreted to the bulk medium when the biomass becomes active again. A kinetic model is proposed which simultaneously explains 246TCP and 24DCP reductive dechlorinations and includes the 246TCP bioaccumulation. The values of the kinetic parameters for 246TCP dechlorination were not affected by bioaugmentation (V(max)=5.3 and 5.1 μM h(-1) and K(s)=5.8 and 13.1 μM for control and bioaugmented sludges, respectively).

中文翻译：

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2,4,6-三氯苯酚对脱硫杆菌菌种改良厌氧颗粒污泥微生物活性的影响

2,4,6-三氯苯酚 (246TCP) 的厌氧降解已经在批量实验中进行了研究。颗粒污泥先前适应 2,4-二氯苯酚 (24DCP)，然后在两个膨胀颗粒污泥床 (EGSB) 反应器中适应 330 μM 246TCPd(-1) 的负载。其中一个反应器用脱硫杆菌菌株进行了生物强化，而另一个用作对照。246TCP 在 250 和 760 μM 之间的浓度下进行了测试。该研究侧重于发酵产物和源自 246TCP 脱氯的氯酚的归宿。该化合物主要影响乙酸盐和丙酸盐的生物降解，在 246TCP 浓度高于 380 μM 时受到抑制。乳酸盐和乙醇也以 760 μM 246TCP 积累。246TCP 浓度高于 380 μM 时强烈抑制产甲烷作用。观察到甲烷的双重产生，这可以通过动力学模型来描述，其中乙酰碎屑产甲烷受到抑制，而氢营养产甲烷几乎不受 246TCP 影响。为对照和生物强化污泥获得的动力学参数的相似性（K(i)=175-200 μM 246TCP 和 n=7）表明产甲烷不受生物强化的影响。此外，246TCP脱氯主要发生在邻位，依次生成24DCP和4-氯苯酚（4CP），最终产物被确定。生物强化并没有显着改善 246TCP 的厌氧生物降解。已经表明，活性生物质能够生物积累 246TCP 和脱氯产物，当生物质再次变得活跃时，它们随后被排泄到大量培养基中。提出了一个动力学模型，它同时解释了 246TCP 和 24DCP 还原脱氯，并包括 246TCP 生物积累。246TCP 脱氯的动力学参数值不受生物强化的影响（V(max)=5.3 和 5.1 μM h(-1) 和 K(s)=5.8 和 13.1 μM，分别用于对照和生物强化污泥）。