Biodegradation of 4-chlorophenol by acclimated and unacclimated activated sludge—Evaluation of biokinetic coefficients

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• 作者：Erkan Sahinkaya and Filiz B. Dilek
• 关键词：Cometabolism ; 4-chlorophenol ; Acclimation ; Inhibition ; Biodegradation
• 刊名：Environmental Research
• 出版年：2005
• 出版时间：2005
• 年：2005
• 卷：99
• 期：2
• 页码：243-252
• 全文大小：330 K

文摘

Unacclimated and acclimated activated sludges were examined for their ability to degrade 4-CP (4-chlorophenol) in the presence and absence of a readily growing substrate using aerobic batch reactors. The effects of 4-CP on the μ (specific growth rate), COD removal efficiency, Y (yield coefficient), and q (specific substrate utilization rate) were investigated. It was observed that the toxicity of 4-CP on the culture decreased remarkably after acclimation. For example, the IC₅₀ value on the basis of μ was found to increase from 130 to 218 mg/L with the acclimation of the culture. Although an increase in 4-CP concentration up to 300 mg/L has no adverse effect on the COD removal efficiency of the acclimated culture, a considerable decrease was observed in the case of an unacclimated culture. Although 4-CP removal was not observed with an unacclimated culture, almost complete removal was achieved with the acclimated culture, up to 300 mg/L. The Haldane kinetic model adequately predicted the biodegradation of 4-CP and the kinetic constants obtained were , 673567127672"">, and . The degradation of 4-CP led to formation of 5-chloro-2-hydroxymuconic semialdehyde, which was further metabolized, indicating complete degradation of 4-CP via a meta-cleavage pathway.