The effect of ozonation on the toxicity and biodegradability of 2,4-dichlorophenol-containing wastewater

摘要: Abstract The ozone degradation of 2,4-dichlorophenol (2,4-DCP), as toxic model pollutant in wastewater, is investigated the presence readily biodegradable substrates. Since a successful treatment does not only depend on elimination compound, proper assessment residual toxicity and/or biodegradability ozonated wastewater necessary. Respirometry used to evaluate biodegradation efficiency and microbial activity both non-acclimated pre-exposed biomass. Ozone pre-treatment results decrease 2,4-DCP an increase chloride concentration. release inversely proportional 2,4-DCP, implying dechlorination aromatic ring first reaction step its decomposition. Furthermore, described by pseudo first-order kinetics. rate decreases when organic matter present extent this depends nature matter. measured COD correspond with mineralization 2,4-DCP. Hence, instead degraded into dehalogenated intermediates. Further, respirometric measurements are performed order investigate effects wastewater. period before biomass observed, so-called lag phase, significantly reduced and, furthermore, maximal Specific Oxygen Uptake Rate (SOUR), indicating activity, increases increasing time. This means that observed reduced. Also, fraction amount refractory because (partial) pollutant. Therefore, can be shorter