Sahinkaya Erkan, Dilek Filiz B
Middle East Technical University, Environmental Engineering Department, 06531 Ankara, Turkey.
J Hazard Mater. 2006 Feb 6;128(2-3):258-64. doi: 10.1016/j.jhazmat.2005.08.002. Epub 2005 Sep 12.
Effect of a biogenic substrate (peptone) concentration on the performance of sequencing batch reactor (SBR) treating 220 mg/l 4-chlorophenol (4-CP) and 110 mg/l 2,4-dichlorophenol (2,4-DCP) mixtures was investigated. In this context, peptone concentration was gradually decreased from 300 mg/l to null in which chlorophenols were fed to the reactor as sole carbon and energy sources. By this way, the effect of peptone concentration on observed yield coefficient (Y), biomass concentration, chlorophenols and COD removal performances were investigated. Decreasing peptone concentration accompanied with lower biomass concentration led to increase in peak chlorophenol and COD concentrations within the reactor during each SBR cycle. This, in turn, caused noteworthy declines in the removal rates as chlorophenol degradations followed Haldane substrate inhibition model. Also, increased peak chlorophenol concentrations led to the accumulation of 5-chloro-2-hydroxymuconic semialdehyde (CHMS), which is -meta cleavage product of 4-CP. Despite the decreased removal rates, complete chlorophenols and CHMS degradation, in addition to high COD removal efficiencies (>90%), were observed for all studied conditions, even chlorophenols were added as sole carbon and energy sources. Another significant point is that 2,4-DCP at slightly elevated concentrations (>20 mg/l) within the reactor caused a strong competitive inhibition on 4-CP degradation. In SBR, feeding the influent to the reactor within a certain period (i.e. filling period) provided dilution of coming wastewater, which decreased the chlorophenols concentrations to which microorganisms were exposed. Therefore, use of SBR may help to avoid both self and competitive inhibitions in the treatment of 4-CP and 2,4-DCP mixture especially in the presence high biogenic substrate concentrations. In addition, isolation and identification studies have indicated that Pseudomonas sp. and Pseudomonas stutzeri were dominant species in the acclimated mixed culture.
研究了生物源底物（蛋白胨）浓度对序批式反应器（SBR）处理220 mg/L 4-氯酚（4-CP）和110 mg/L 2,4-二氯酚（2,4-DCP）混合物性能的影响。在此背景下，蛋白胨浓度从300 mg/L逐渐降低至零，其中氯酚作为唯一的碳源和能源输入到反应器中。通过这种方式，研究了蛋白胨浓度对观察到的产率系数（Y）、生物量浓度、氯酚和COD去除性能的影响。蛋白胨浓度降低伴随着生物量浓度降低，导致每个SBR周期内反应器中氯酚和COD的峰值浓度增加。这反过来又导致去除率显著下降，因为氯酚的降解遵循Haldane底物抑制模型。此外，氯酚峰值浓度的增加导致了5-氯-2-羟基粘康酸半醛（CHMS）的积累，CHMS是4-CP的间位裂解产物。尽管去除率有所下降，但在所有研究条件下均观察到氯酚和CHMS完全降解，以及较高的COD去除效率（>90%），即使氯酚作为唯一的碳源和能源添加。另一个重要点是，反应器内浓度略有升高（>20 mg/L）的2,4-DCP对4-CP降解产生了强烈的竞争性抑制。在SBR中，在一定时间段（即进水期）将进水输入反应器可对进入的废水进行稀释，从而降低微生物接触的氯酚浓度。因此，使用SBR可能有助于避免在处理4-CP和2,4-DCP混合物时出现自身抑制和竞争性抑制，尤其是在生物源底物浓度较高的情况下。此外，分离和鉴定研究表明，假单胞菌属和施氏假单胞菌是驯化混合培养物中的优势菌种。
