title: Degradation of chlortetracycline in wastewater sludge by ultrasonication, Fenton oxidation, and ferro-sonication.
abstract: Residual emerging contaminants in wastewater sludge remain an obstacle for its wide and safe applications such as landfilling and bio-fertilizer. In this study, the feasibility of individual ultrasonication (UlS) and Fenton oxidation (FO) and combined, Ferro-sonication processes (FO) on the degradation of chlortetracycline (CTC) in wastewater sludge was investigated. UlS parameters such as amplitude and sonication time were optimized by response surface methodology (RSM) for further optimization of FS process. Generation of highly reactive hydroxyl radicals in FO and FS processes were compared to evaluate the degradation efficiency of CTC. Increasing in the ratio of hydrogen peroxide and iron concentration showed increased CTC degradation in FO process; whereas in FS, an increase in iron concentration did not show any significant effect (p>0.05) on CTC degradation in sludge. The estimated iron concentration in sludge (115mg/kg) was enough to degrade CTC without the addition of external iron. The only adjustment of sludge pH to 3 was enough to generate in-situ hydroxyl radicals by utilizing iron which is already present in the sludge. This observation was further supported by hydroxyl radical estimation with adjustment of water pH to 3 and with and without the addition of iron. The optimum operating UlS conditions were found to be 60% amplitude for 106min by using RSM. Compared to standalone UlS and FO at 1:1 ratio, FS showed 15% and 8% increased CTC degradation respectively. In addition, UlS of sludge increased estrogenic activity 1.5 times higher compared to FO. FS treated samples did not show any estrogenic activity.
authors: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
authors: Rama
authors: R
authors: Pulicharla
authors: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada. Electronic address: satinder.brar@ete.inrs.ca.
authors: Satinder Kaur
authors: SK
authors: Brar
authors: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
authors: Tarek
authors: T
authors: Rouissi
authors: Phytronix Technologies, 4535 Boulevard Wilfrid Hamel, Québec G1P 2J7, Canada.
authors: Serge
authors: S
authors: Auger
authors: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
authors: Patrick
authors: P
authors: Drogui
authors: CO2 Solutions Inc., 2300, Rue Jean-Perrin, Québec, Québec G2C 1T9, Canada.
authors: Mausam
authors: M
authors: Verma
authors: Department of Civil Engineering, University of Nebraska-Lincoln, N104 SEC PO Box 886105, Lincoln, NE 68588-6105, USA.
authors: Rao Y
authors: RY
authors: Surampalli
mesh_terms: D002751:Chlortetracycline / Q000737:chemistry* / Q000302:isolation & purification*; D004967:Estrogens / Q000737:chemistry / Q000302:isolation & purification; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D012722:Sewage / Q000737:chemistry*; D013010:Sonication; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*
chemical_list: D004967:Estrogens; C045076:Fenton's reagent; D012722:Sewage; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D007501:Iron; D002751:Chlortetracycline
keywords: Chlortetracycline; Fenton; Ferro-sonication; Sludge; Toxicity; Ultrasonication