Solar photocatalytic oxidation of recalcitrant natural metabolic by-products of amoxicillin biodegradation

Abstract

The contamination of the aquatic environment by non-metabolized and metabolized antibiotic residues has brought the necessity of alternative treatment steps to current water decontamination technologies. This work assessed the feasibility of using a multistage treatment system for amoxicillin (AMX) spiked solutions combining: i) a biological treatment process using an enriched culture to metabolize AMX, with ii) a solar photocatalytic system to achieve the removal of the metabolized transformation products (TPs) identified via LC-MS, recalcitrant to further biological degradation. Firstly, a mixed culture (MC) was obtained through the enrichment of an activated sludge sample collected in an urban wastewater treatment plant (WWTP). Secondly, different aqueous matrices spiked with AMX were treated with the MC and the metabolic transformation products were identified. Thirdly, the efficiency of two solar assisted photocatalytic processes (TiO2/UV or Fe 3+ /Oxalate/H2O2/UV-Vis) was assessed in the degradation of the obtained TPs using a lab-scale prototype photoreactor equipped with a compound parabolic collector (CPC). Highest AMX specific biodegradation rates were obtained in buffer and urban wastewater (WW) media (0.10 ± 0.01 and 0.13 ± 0.07 gAMX gbiomass -1 h -1 , respectively). The resulting TPs, which no longer presented antibacterial activity, were identified as amoxicilloic acid (m/ z = 384). The performance of the Fe /Oxalate/H2O2/UV-Vis system in the 2 removal of the TPs from WW medium was superior to the TiO2/UV process (TPs no longer detected after 40 min (QUV = 2.6 kJ L -1 ), against incomplete TPs removal after 240 min (QUV = 14.9 kJ L -1 ), respectively).

Selecting the best AOP for isoxazolyl penicillins degradation as a function of water characteristics: Effects of pH, chemical nature of additives and pollutant concentration

“…Previous investigations have revealed that the degradation of recalcitrant compounds may lead to the creation of harmful solutions (Bernabeu et al, 2012;Pereira et al, 2014;Wu et al, 2009). To evaluate the extent of degradation during the UV/H 2 O 2 /Fe 2þ , UV/ TiO 2 and US processes, the evolution of DXC and dissolved organic carbon (DOC) was determined (Fig.…”

Degradation of Penicillin G by Visible Light Irradiation-Assisted Biotransformation by Whole Cell paracoccus sp .

“…Regarding the technology for β-lactam antibiotic degradation, various methods such as nano ltration [26], ozonation [27,28], biodegradation [29], surface adsorption [30], advanced oxidation [19,31] and photocatalytic processes [22,32] have been reported to remove β-lactam antibiotics. However, biodegradation typically results in incomplete mineralization; furthermore, low degradation e ciency has been observed by several authors [33,34]. Mineralization degradation of antibiotic residues occur at different scales, including in wastewater, antibiotic mycelium, and other ecological environments.…”

Denitrification in an integrated bioelectro-photocatalytic system

“…Currently, physicochemical methods such as ion exchange, reverse osmosis, and electrodialysis have been used to remove nitrate from water, but they generally require further treatment of the concentrated solution, cause the losses of other useful elements (Chaplin et al, 2012;Li et al, 2016;Zhang et al, 2014), and usually consume high energy. Biological approaches are useful for nitrate removal from wastewater, though their application for water environmental remediation is limited, due to the challenges of performance maintenance and secondary pollution associated with carbon source supply and the pathogen concerns (Cardoso et al, 2016;Cheng et al, 2012;Pereira et al, 2014). Performance of a biological treatment system is affected by many factors, especially microbial communities involved in the system.…”