Effects of the cometabolitegrowth substrate ratio on the aerobic degradation of 4-monochlorophenol

摘要

Chlorinated phenolic compounds like 4-monochlorophenol (4CP) are characterized by high toxicityneven at relatively low concentrations and by strong persistency in both water and soils. Sincencometabolism was proved to enhance 4CP biological removal, a conventional Sequencing BatchnReactor (SBR) was used in this study for the cometabolic aerobic degradation of 4CP at differentninfluent concentrations and volumetric organic loading rates (40–50 mg/L and 0.129–0.323nkgCOD-4CP/m3 u0002 d, respectively), with sodium acetate (NaAc) as the growth substrate. The effects ofndifferent 4CP/NaAc ratios on SBR performances were evaluated in terms of 4CP removalnefficiencies and maximum specific removal rates in order to maximize reactor performances: andecrease in NaAc dosage as external growth substrate would lead to definitely lower operatingncosts. A positive correlation was observed between 4CP maximum specific removal rates and thenapplied 4CP/NaAc ratios, thus making further reduction in NaAc dosage possible.