Identification of resistant pharmaceuticals in ozonation using QSAR modeling and their fate in electro-peroxone process

• The abatements of 89 pharmaceuticals in secondary effluent by ozonation and the electro-peroxone (Eperoxone) process were investigated. Based on the results, a quantitative structure-activity relationship(QSAR) model was developed to explore relationship between chemical structure of pharmaceuticalsand their oxidation rates by ozone. The orthogonal projection to latent structure (OPLS) method wasused to identify relevant chemical descriptors of the pharmaceuticals, from large number ofdescriptors, for model development. The resulting QSAR model, based on 44 molecular descriptorsrelated to the ozone reactivity of the pharmaceuticals, showed high goodness of fit (R2 = 0.963) andpredictive power (Q2 = 0.84). After validation, the model was used to predict second-order rateconstants of 491 pharmaceuticals of special concern (kO3 ) including the 89 studied experimentally. The predicted kO3 values and experimentally determined pseudo-first order rate constants of thepharmaceuticals’ abatement during ozonation (kOZ) and the E-peroxone process (kEP) were then usedto assess effects of switching from ozonation to the E-peroxone process on removal of thesepharmaceuticals. The results indicate that the E-peroxone process could accelerate the abatement ofpharmaceuticals with relatively low ozone reactivity (kO3 < ~102 M–1.s–1) than ozonation (3–10 min versus 5–20 min). The validated QSAR model predicted 66 pharmaceuticals to be highly O3-resistant.The developed QSAR model may be used to estimate the ozone reactivity of pharmaceuticals ofdiverse chemistry and thus predict their fate in ozone-based processes.

Subject headings

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Keyword

Ozone

Electro-peroxone

Wastewater

Quantitative structure activity relationship

Advanced oxidation processes

Publication and Content Type

vet (subject category)

art (subject category)