Work

A full-scale evaluation of the effects of different disinfection methods on the removal of contaminants of emerging concern

Year: 2025

Type: article

Abstract: Contaminants of Emerging Concern (CECs) have garnered increasing attention in the last years due to their extremely wide diffusion and persistence in the environment. Furthermore, despite the huge number of studies performed so far, there is still an the uncomplete knowledge about their fate, behavior and effects on ecosystem and human health. It has been demonstrated that the Wastewater Treatment Plants (WWTPs) for domestic sewage, operating through the traditional layout (i.e. preliminary, primary and secondary treatments) are unable to effectively remove many of CECs. Most of the studies focused on the effects of the secondary treatment processes, whereas a few data are available on removal achieved by the disinfection methods. Among these, chlorination is facing a progressive replacement due to the risk for human health posed by its by-products which are known to be cancerogenic. Therefore, other types of disinfecting agents, such as peracetic acid and UV radiations, are increasingly implemented in the WWTPs. The effects of these disinfection processes on CECs have not been fully investigated yet, particularly under the more complex real conditions. The aim of the present study, conducted jointly with one of the largest Italian utilities, was to investigate and compare the CECs removal by peracetic acid, sand filtration followed by UV radiation and sodium hypochlorite disinfections in three different full-scale plants. None of these disinfection methods was able to provide a high reduction rate, with the lowest removal achieved by chlorination. With respect to the different CECs, peracetic acid removed methamphetamine and sulfamethoxazole a slightly better; when its dosage was significantly increased (in laboratory tests), it was observed an improvement only on lincomycin (up to 61%). Combination of filtration and UV disinfection showed a higher degradation of benzoylecgonine, sulfamethoxazole, ketoprofen and trimethoprim. The risk assessment conducted on the effluent treated by the different disinfection methods highlighted an environmental risk ranging from low to medium considering the release to a river or soil, respectively and a low sanitary risk for the reuse of the treated effluent in agriculture.

Source: Journal of Water Process Engineering

DOI: 10.1016/j.jwpe.2025.107686