Effect of wastewater chlorination on endocrine disruptor removal

Abstract

Endocrine disrupting chemicals (EDCs) are compounds of mainly anthropogenic origin that interfere with the endocrine system of animals and humans thus causing a series of disorders. Wastewater treatment plants are one of the major routes for transporting such chemicals to the water courses. In the context of this study, several chlorination batch tests were performed in order to assess the effectiveness of chlorination to remove bisphenol A (BPA), triclosan (TCS), nonylphenol (NP) and its ethoxylates (NP1EO and NP2EO) from secondary effluent. According to the results, an appreciable removal of NP, BPA and TCS to the order of 60-84% was observed as an effect of moderate chlorination doses. This was not the case for NP1EO and NP2EO as even at high chlorine doses, removal efficiencies were lower (37% for NP1EO and 52% for NP2EO). Removal efficiencies of NP, BPA and TCS are practically independent of contact time, although this was not the case for NP1EO and NP2EO. Based on toxicity experiments, it is anticipated that following chlorination of the target chemicals, production of more toxic metabolites is taking place. Therefore the effectiveness of chlorination to remove EDCs is questionable and more research is needed to guarantee safe wastewater reuse.

Investigation on the montmorillonite adsorption of biocidal compounds incorporating thermodynamical-based multicomponent adsorption isotherm

“…Several processes have been proposed to remove those micropollutants such as UV/TiO 2 photocatalysis [7,10], membrane bioreactor [11], chemical oxidation [12], chlorination [9,13], ozonisation [12,14], and activated carbon adsorption [14][15]. Amongst those processes, adsorption shows a promising prospect in removal efficiency and cost feasibility.…”

A Review on the Fate of Legacy and Alternative Antimicrobials and Their Metabolites during Wastewater and Sludge Treatment

“…However, many of these degradation products are far more toxic and biopersistant than the parent TCS. For example, Noutsopoulos et al [97] found 92% TCS removal at a free chlorine dose of 40 mg Cl 2 /L and at a contact time of less than 5 min, but observed a 50-to 100-fold increase in Vibrio fischeri toxicity compared to TCS prior to chlorination. Multiple TCS-containing personal care products have also been shown to react with free chlorine to form higher-chlorinated TCS intermediates, including dichloro-2-(2,3-dichlorohenoxy)phenol and trichloro-2-(2,3-dichlorohenoxy)phenol.…”

Emerging Pollutants – Part II: Treatment

“…Chlorination was questioned as a potential treatment technology for the EDCs BPA, triclosan, and NP from secondary wastewater effluent, and was not found to be completely effective (Noutsopoulos et al, 2013). NP, BPA, and triclosan were effectively removed (60-84%) at moderate chlorine doses, however, ethoxylates of NP (NP1EO and NP2EO) showed removal efficiencies of <37%.…”