Emerging technologies for treatment of antibiotic residues from wastewater influent/effluent for sustainable environment: A case study with NFC-doped titania immobilized on polystyrene as an efficient technology

Abstract

In this study, 5 urban and 2 industrial wastewater treatment plants (WWTPs) were investigated. Raw wastewaters and effluents of WWTPs were characterized in terms of both organic and inorganic pollutants and antibiotic residues. According to the analysis results; organic pollutants for raw wastewaters and influents in urban WWTP were measured between 412 and 921 ​mg ​L−1 for COD, 345–421 ​mg ​L−1 for TOC, 61–160 ​mg ​L−1 for COD, 48–83 ​mg ​L−1 for TOC, respectively. However, in industrial WWTPs, these values were determined in raw wastewaters between 1404 and 2367 ​mg ​L−1 for COD, 821–826 ​mg ​L−1 for TOC and in effluents between 272 and 408 ​mg ​L−1 for COD and 97–208 ​mg ​L−1 for TOC, respectively.In addition, in the characterization study of antibiotic residues by the results of HPLC/MS-MS measurements, the amounts of Ciprofloxacin (from the fluoroquinolones), Erythromycin (from the macrolides group) and Sulfamethoxasol (from the sulfonamide group), which are one of the three main groups of antibiotics in the waste water samples, were found in high amounts in both urban and industrial WWTPs despite the biological treatment process. More antibiotic residues (Erythromycin-ERY, Ciprofloxacin-CIP and Sulfamethoxasol-SMX) were detected in untreated raw wastewater compared to effluent wastewater. While CIP antibiotic was not found only one urban WWTP, the highest amounts in the effluents of 4 urban WWTPs were measured between 13,800 ​ng ​L−1 and 38,800 ​ng ​L−1. Moreover, ERY is only detected in high amount in one urban WWTP raw and effluent wastewater as 23,100 ​ng ​L−1 and 5430 ​ng ​L−1, respectively. The SMX was detected in 2 separates urban WWTPs at a value of 19,700 ​ng ​L−1 in the raw wastewater sample and at a value 10,100 ​ng ​L−1 in effluent sample of another urban WWTP. Antibiotic residue removal ratios after Advanced Oxidation Process using specially prepared NFC-doped TiO2 photocatalyst immobilized on polystyrene (PS) cup inner surface at amount 0.45 ​g were determined as 97%–~100% for CIP, 100% for ERY, 86%–~100% for SMX, 57%–64% for COD and 61,5%–72% for TOC, respectively.According to the above mentioned results, this study proved that photocatalytic oxidation processes performed under visible light with a specially prepared immobilized form (PS/Cup–NFC–0.45 ​g) photocatalyst provide higher antibiotic removal from both urban and industrial wastewater. Thus, these results showed us that if the application of NFC-doped Titania, immobilized on polystyrene, can be integrated with an appropriate reactor design on the real/pilot scale, this technology can be proposed as an efficient technology for sustainable environment.