Persistent contaminants of emerging concern in ozone‐biofiltration systems: Analysis from multiple studies

Abstract

Water quality, in combination with design and operational data collected from multiple studies, was assessed to benchmark the performance of ozone‐biologically active filtration in reuse applications. A total of 149 contaminants of emerging concern, representative of multiple categories and chemical structures, were prioritized and systematically compared to elucidate apparent differences in removal capabilities as affected by multiple factors such as influent water matrix, ozone‐to‐organic carbon ratio, empty bed contact time, filtration media type, and initial media condition. The results were consistent with earlier findings for the removal of highly amenable compounds but demonstrate inconsistencies and knowledge gaps across multiple facilities for the more persistent compounds. Analysis of this multistudy data‐mining effort also demonstrates a complicated interplay between contaminant removal and numerous design and operational variables. Hence, further systematic investigation is warranted to elucidate the underlying removal mechanisms.

Per‐ and polyfluoroalkyl substance removal in carbon‐based advanced treatment for potable reuse

“…During the sampling events, O 3 :TOC ratio setpoints ranged between 0.8 and 1.3, corresponding to an ozone dose range of 5.0–8.6 mg/L. Studies show that, although ozone is effective in oxidizing PFAAs (Crone et al, 2019; Glover et al, 2018; Schröder & Meesters, 2005), it may increase the concentration of targeted PFAAs by oxidizing precursors (Dickenson et al, 2015; Sari et al, 2020). PFBS increased by an average of 31% after ozonation.…”

Biofiltration for treatment of recent emerging contaminants in water: Current and future perspectives

“…Even though there are reports on the efficient removal of microplastics by WWTPs, some microplastics are present in the effluent, requiring the development of microplastic‐targeted treatment processes (Magni et al, 2019; Sun et al, 2019). It was found that ozonation in the common O 3 /BAC treatment train could not remove the flame retardant and plasticizer tris(2‐chloroethyl)phosphate (TCEP), and the removal relies on biofiltration (Sari et al, 2020). A study on the removal of emerging contaminants by the treatment train of sand/anthracite filter followed by BAC showed that even though TCEP was low in concentration, but it persisted in the effluent (Fu et al, 2019).…”

“…A recent data‐mining study (Sari et al, 2020) on the removal of emerging contaminants by O 3 /biological active filtration (BAF) also reported that ozonation was not effective for PFAS removal, and the removal should be mainly by adsorption, in which the effectiveness probably relies on the media condition used (e.g., virgin, regenerated, or exhausted). Compared to conventional biodegradation, BAC should have greater potential for PFAS biodegradation since the carbon‐based media could promote more microbial diversity in biofilms (Vignola et al, 2018).…”

Investigating machine learning models to predict microbial activity during ozonation–biofiltration

“…For ozonation and biological media filtration (BMF), however the water matrix characteristics play a crucial role in the disinfection effectiveness which has limited the use of indicators such as ozone dose and CT, applied elsewhere in water treatment. [8][9][10] This limitation has impeded the formal attribution of LRV credits to ozonation and BMF for wastewater in many jurisdictions. LRV credits have been awarded to postozonation at Melbourne Water's Eastern Treatment Plant (ETP) (the subject of this study) on the basis of CT disinfection.…”