Photosonochemical degradation of butyl-paraben: Optimization, toxicity and kinetic studies

Rimeh Daghrir (1) , Aicha Dimboukou-Mpira (2) , Brahima Seyhi (3) , Patrick Drogui (3)

1 Centre des technologies de l'eau
2 LGC - Laboratoire de Génie Chimique
3 INRS - ETE - Centre Eau Terre Environnement [Québec]

The objective of the present work is to evaluate the potential of a photosonolysis process for the degradation of butyl-paraben (BPB). After 120 min of treatment time, high removal of BPB was achieved by the photosonolysis (US/UV) process (88.0 ± 0.65%) compared to the photochemical (UV) and the conventional ultrasonication (US) processes. Several factors such as calorimetric power, treatment time, pH and initial concentration of BPB were investigated. Using a 24 factorial matrix, the treatment time and the calorimetric power are the main parameters influencing the degradation rate of BPB. Subsequently, a central composite design methodology has been investigated to determine the optimal experimental parameters for BPB degradation. The US/UV process applied under optimal operating conditions (at a calorimetric power of 40 W during 120 min and under pH 7) is able to oxidize around 99.2 ± 1.4% of BPB and to record 43.3% of mineralization. During the US/UV process, BPB was mainly transformed into 1 hydroxy BPB, dihydroxy BPB, hydroquinone and 4-hydroxybenzoic acid. Microtox biotests (Vibrio fisheri) showed that the treated effluent was not toxic. The pseudo-first order kinetic model (k = 0.0367 min− 1) described very well the oxidation of BPB.

Mots clés: Photosonolysis; Butyl-paraben; Response surface methodology; Wastewater treatment

Domaines: Génie chimique; Génie des procédés

Rimeh Daghrir, Aicha Dimboukou-Mpira, Brahima Seyhi, Patrick Drogui. Photosonochemical degradation of butyl-paraben: Optimization, toxicity and kinetic studies. Science of the Total Environment, 2014, 490, pp.223-234. ⟨10.1016/j.scitotenv.2014.05.006⟩. ⟨hal-01919463⟩