Degradation kinetics of chlortetracycline in wastewater using ultrasonication assisted laccase

Abstract

Chlortetracycline (CTC) is widely used as a veterinary antibiotic and is considered as a recalcitrant pollutant. In this study, spiked CTC (2 mg L -1 ) in wastewater was degraded using laccase from the white rot fungi, Trametes Versicolor combined with ultrasonication (UlS). Over 60% of CTC was removed in 2h by UlS assisted laccase (UAL) treatment where laccase treatment alone took 2 days to degrade 87% of CTC under similar CTC concentration (2 mg L -1 ), laccase dose (0.5 IU) and pH 6.0 conditions. UAL treatment showed 5.3 folds higher CTC degradation rate compared to laccase alone treatment at pH 6.0. Further, pH optimization of UAL treatment was done and pH 4.5 was found to be optimum wherein 80% of CTC degradation was obtained which is 2.6 folds higher compared to degradation at pH 6.0. The UAL treatment with optimized pH was not only increased CTC degradation efficiency (~80%) but also reduced the degradation time to 2h. The obtained results highlighted the enhanced degradation rate, efficiency and unaltered stability of laccase during UAL treatment which can be used for oxidizing other tetracycline groups of antibiotics. Moreover, laccase and UAL treatments showed similar degradation products and no estrogenic activity.

Laccases: structure, function, and potential application in water bioremediation

“…Enzyme from supernatant extractChlortetracycline (CTC) degradationCTC at 2 mg/L, laccase dose at 0.5 IU, pH 4.5 or 6.0, and ultrasonication60% of CTC, considered as a recalcitrant pollutant, was removed in 2 h by ultrasonication and assisted laccase at pH 6.0. While at pH 4.5, 80% of CTC was degraded, resulting non estrogenic by productsOxidation of C–C and C–O bonds[51] Pleurotus ostreatus FPPDA medium at 25 °C, and added ciprofloxacin (CIP: at 100, 200, 300, 400 and 500 ppm). The enzyme was secretedDegradation of ciprofloxacin (CIP)Fungi growth by 14 days with 100, 200, 300, 400 and 500 ppm of CIPAntibiotic degradation of about 68.8, 94.25 and 91.34% was estimated after 14 days of incubation at 500 ppm CIPNot reported[52] Pycnoporus sanguineus CS43 f FSTR of 10 L with 36.8% tomato juice medium, by 15 days, induced with CuSO 4 and soybean oil at 48 h. LacI and LacII were purifiedDegradation of endocrine disrupting chemicals (EDCs): nonylphenol and triclosan (a biocide)EDC at 10 ppm final concentration were prepared in pH 5 McIlvaine buffer with 100 U/L laccase.…”

Characterization of a Novel Laccase LAC-Yang1 from White-Rot Fungus Pleurotus ostreatus Strain Yang1 with a Strong Ability to Degrade and Detoxify Chlorophenols

“…The four copper atoms in the active site of laccase combine with oxygen to form a copper superoxide complex and an electron transport chain for redox reactions [ 5 , 6 , 7 ]. In recent years, laccase has demonstrated good performance in the degradation of industrial dyes [ 8 ], polycyclic aromatic hydrocarbons [ 9 ], endocrine disruptors such as bisphenol A [ 10 , 11 ], pesticides [ 12 ], mycotoxin [ 13 ], antibiotics [ 14 , 15 ], diclofenac [ 16 ] and other low-degradability organic pollutants.…”

UV-enhanced nano-nickel ferrite-activated peroxymonosulfate for the degradation of chlortetracycline hydrochloride in aqueous solution

“…[1][2][3][4] Chlortetracycline hydrochloride (CTH) is a tetracyclic broad-spectrum antibiotic, and due to its low price and potential for promoting the growth of livestock, it has been widely used in animal husbandry. [5][6][7] Nevertheless, the absorption capacity of CTH by humans and animals is limited. These high concentrations of CTH have adverse effects on the ecosystem and human health.…”