Effects of the cometabolite/growth substrate ratio on the aerobic degradation of 4-monochlorophenol.
Chlorinated phenolic compounds like 4-monochlorophenol (4CP) are characterized by high toxicity even at relatively low concentrations and by strong persistency in both water and soils. Since cometabolism was proved to enhance 4CP biological removal, a conventional Sequencing Batch Reactor (SBR) was used in this study for the cometabolic aerobic degradation of 4CP at different influent concentrations and volumetric organic loading rates (40-50 mg/L and 0.129-0.323 kgCOD-4CP/m3·d, respectively), with sodium acetate (NaAc) as the growth substrate. The effects of different 4CP/NaAc ratios on SBR performances were evaluated in terms of 4CP removal efficiencies and maximum specific removal rates in order to maximize reactor performances: a decrease in NaAc dosage as external growth substrate would lead to definitely lower operating costs. A positive correlation was observed between 4CP maximum specific removal rates and the applied 4CP/NaAc ratios, thus making further reduction in NaAc dosage possible.
University of Cagliari, Department of Geoengineering and Environmental Technologies (DIGITA), piazza d'Armi 1, 09123, Cagliari, Italy. smilia@unica.it
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Milia
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Cappai
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De Gioannis
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Carucci
D000332:Aerobiosis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D019149:Bioreactors / Q000382:microbiology; D002733:Chlorophenols / Q000302:isolation & purification*; D019346:Sodium Acetate / Q000494:pharmacology; D014835:Volatilization / Q000187:drug effects
D002733:Chlorophenols; C029107:4-chlorophenol; D019346:Sodium Acetate