Enhanced Biodegradation of Carbamazepine after UV/H₂O₂ Advanced Oxidation

Abstract

Carbamazepine is one of the most persistent pharmaceutical compounds in wastewater effluents due to its resistance to biodegradation-based conventional treatment. Advanced oxidation can efficiently degrade carbamazepine, but the toxicity and persistence of the oxidation products may be more relevant than the parent. This study sets out to determine whether the products of advanced oxidation of carbamazepine can be biotransformed and ultimately mineralized by developing a novel methodology to assess these sequential treatment processes. The methodology traces the transformation products of the (14)C-labeled carbamazepine during UV/hydrogen peroxide advanced oxidation and subsequent biotransformation by mixed, undefined cultures using liquid scintillation counting and liquid chromatography with radioactivity, mass spectrometry, and UV detectors. The results show that the oxidation byproducts of carbamazepine containing a hydroxyl or carbonyl group can be fully mineralized by a mixed bacterial inoculum. A tertiary treatment approach that includes oxidation and biotransformation has the potential to synergistically mineralize persistent pharmaceutical compounds in wastewater treatment plant effluents. The methodology developed for this study can be applied to assess the mineralization potential of other persistent organic contaminants.

Ozone enhances biodegradability of heavy hydrocarbons in soil

“…Integrating advanced oxidation with bioremediation is a means to increase the biodegradability and water solubility of recalcitrant organic compounds, such as humics in natural waters, PAHs and organics in landfill leachate (Brame et al, 2013;Goi et al, 2006;Jung and Choi, 2003;Jung et al, 2005;Keen et al, 2012;Li et al, 2012;Rittmann et al, 2002;Wu et al, 2004), thus allowing microorganisms to mineralise the residuals.…”

Trace organic contaminants in biosolids: Impact of conventional wastewater and sludge processing technologies and emerging alternatives

“…UV only, UV/H 2 O 2 , and UV/TiO 2 ) can result to the removal of TrOCs through oxidative degradation [9,150], and also through the evaporation of volatile or semi-volatile TrOCs when temperature rises during UV irradiation [146,150]. It also has potential to enhance biodegradation by oxidising persistent TrOCs into smaller, more biodegradable products [147]. Varying TrOC removal has been observed depending on UV treatment conditions (Table 2) [9,146,147].…”

“…It also has potential to enhance biodegradation by oxidising persistent TrOCs into smaller, more biodegradable products [147]. Varying TrOC removal has been observed depending on UV treatment conditions (Table 2) [9,146,147]. Salihoglu et al [146] found that UV treatment caused only 15-21% removal of polycyclic aromatic hydrocarbons from sludge through volatilisation.…”

“…The observed degradation rate constants of the TrOCs under UV/H 2 O 2 treatment were 45-197 and 11-53 times greater than those under UV treatment alone and H 2 O 2 treatment alone, respectively. Keen et al [147] found that 14 Clabelled carbamazepine was photodegraded into smaller products containing hydroxyl and carbonyl moieties through UV/H 2 O 2 treatment. Furthermore, UV-treatment of wastewater increased the mineralisation of carbamazepine by 45% in batch tests, indicating that UV/H 2 O 2 is a potential pre-treatment process targeting highly recalcitrant TrOCs.…”

Aquatic photolysis of carbamazepine by UV/H2O2 and UV/Fe(II) processes

“…In addition, CBZ has some effect on human embryonic cells, such as growth inhibition and morphological changes, even at a range environmental concentration of ng/L [18]. However, CBZ is one of the most persistent pharmaceuticals of concern in water and is resistant to both the conventional water treatment process and biodegradation [19]. Thus, advanced oxidation processes (AOPs) have become the important treatment methods in various waters [20].…”