Assessing strategies to improve the efficacy and efficiency of direct filtration plants facing changes in source water quality from anthropogenic and climatic pressures

Monitoring natural organic matter in drinking water treatment with photoelectrochemical oxygen demand

“…The pilot‐plant, which replicates the treatment train of the full‐scale ATL_A plant (as described in Table 1), operated at an average flow of 10 L/min and the same operational conditions (e.g., coagulant dose, pH, flocculation times) as the full‐scale plant. Further information on the layout of the pilot‐plant train is described in DeMont et al (2021). The pilot‐plant samples were analyzed for UV 254 , and peCOD on‐site.…”

“…Wide‐spread accounts of brownification—increasing concentration of natural organic matter (NOM)—and shifts in the NOM character have been reported in surface waters across the Northern Hemisphere (Anderson et al, 2017; Anderson, DeMont et al, 2023; Clair et al, 2011; DeMont et al, 2021; Garmo et al, 2020; Monteith et al, 2007; Redden et al, 2021; Ritson et al, 2014). These changes are frequently linked to climate change, reversal of acidification (e.g., acid rain), or land‐use changes (Anderson, DeMont et al, 2023; Kritzberg et al, 2020).…”

Adapting direct filtration to increasing source water dissolved organic carbon using clarification and granular activated carbon

“…Aside from increasing coagulant dosing and partially substituting coagulant with cationic polyelectrolytes (DeMont et al, 2021), limited research exists on approaches that direct filtration facilities can employ to address variations in source water quality. Implementing clarification may be necessary to overcome the heightened demand for coagulants resulting from increased NOM load.…”

“…Direct filtration facilities in particular face significant challenges as they have limited capacity to increase coagulant dosage without compromising filter performance (Anderson et al, 2017;Anderson et al, 2023;DeMont et al, 2021). Many direct filtration facilities were built during a time (e.g., 1970s-1980s) when surface waters were clear due to chronic acidification (DeMont et al, 2021), and in regions that are now experiencing increasing NOM concentration (DeMont et al, 2021;Edzwald et al, 1987;Eikebrokk, 1999;Graham et al, 1992;McCormick & King, 1982;Pernitsky et al, 2011). The authors have previously demonstrated how direct filtration can be impacted by changing source water quality-a 1.7-fold increase in NOM concentration caused alum dosing to increase at a similar rate resulting in compromised filter performance (Anderson et al, 2017).…”