Contaminants of emerging concern removal from real wastewater by UV/free chlorine process: A comparison with solar/free chlorine and UV/H2O2 at pilot scale. (December 2019)

• Record Type: Journal Article
• Authors: Cerreta, Giusy; Roccamante, Melina A.; Oller, Isabel; Malato, Sixto; Rizzo, Luigi
• Is Part Of: Chemosphere. Volume 236(2019)
• Publication Date: 2019-12
• Subjects: Advanced oxidation processes -- Chlorine -- Pesticides -- Pharmaceuticals -- Photo driven processes -- Wastewater reuse; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.124354
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The removal of contaminants of emerging concern (CECs) from urban wastewater treatment plants (UWTPs) is really important to minimize the risk for human health and environment. In this study, the homogeneous advanced oxidation process (AOP) UV-C/free chlorine (UV–C/FC) was investigated at pilot scale in the degradation of a mixture of four CECs, in different water matrices and compared to a consolidated AOP, namely UV-C/H2 O2 . As matter of fact 90% degradation of CECs was observed after 15 min (QUVC = 0.33 kJ L −1 ) by UV-C/FC (5 mg L −1 of FC) and 30 min (0.67 kJ L −1 ) by UV-C/H2 O2 (5 mg L −1 of H2 O2 ) in natural water. However, CECs degradation by UV-C/H2 O2 and UV-C/FC was comparable (>82%) in wastewater samples, under the investigated conditions (60 min, 1.33 kJ L −1 ). The effect of sunlight/FC process on the target CECs was also investigated (in a compound parabolic collector based reactor). Interestingly, a different behaviour was observed between the two light sources. In particular, a total removal of carbamazepine (CBZ) and imidacloprid (IMD) was observed for UV-C/FC process with 0.27 kJ L −1 and 10 mgL −1 of FC, while, in the sunlight/FC process (same FC dose), CBZ total removal took place quite fast (0.50 kJ L −1 ), but 90% removal of IMD was observed only after 60 min (7.09 kJ L −1 ). In conclusion, UV-C/FC process can be an interesting solution for tertiary treatment of urban wastewater for the removal of CECs and sunlight/FC is worthy of further investigation to evaluate its possible application in small UWTPs. Graphical abstract: Image 1 Highlights: UV-C/FC was found to be effective in the degradation of the target CECs. UV-C/FC was more effective than UV-C/H2 O2 in the removal of CECs in natural water. UV-C/FC was less effective than UV-C/H2 O2 in the removal of CECs in wastewater. Light sources (UV–C Vs sunlight) affected the degradation of the target CECs by light/FC. Sunlight/FC is worthy of further investigation to evaluate its possible application in small UWTPs.