Extensions and Verification of the Water Treatment Plant Model for Disinfection By-Product Formation

Peer Reviewed: Disinfection Byproducts: The Next Generation

“…ity-wide average analysis was restricted to a subset of women for whom exposure assessment was considered to be more accurate, a statistically significant three-fold increase in spontaneous abortion was found for those with a high personal exposure (≥75 µg/L THMs, ≥5 glasses of cold tap water per day). Efforts are also under way to improve models for predicting DBP formation in drinking water treatment (20,21), and this may provide more accurate exposure information for use in epidemiological studies.…”

Temporal variations of de facto wastewater reuse and disinfection by-products in public water systems in the Shenandoah River watershed, USA

“…Under that condition, HAA5 concentrations as a function of de facto reuse were generally highest in quarter 2, and then progressively lower in quarters 3, 4, and 1 (Figure 7(b)). The HAA5 concentration is affected more than that of THM4 by several factors which may have led to the differences observed: (1) the hydrophobicity of natural organic matter (NOM) (greater hydrophobicity is associated with higher HAA5 concentrations (Solarik et al 2000;Liang & Singer 2003); and (2) the relatively lower temperatures in quarter 2 than 3. HAA5 is susceptible to biodegradation, which would be likely to occur faster at the higher temperatures in quarter 3 (Bayless & Andrews 2008).…”

Reuse treatment with ozonation, biofiltration, and activated carbon adsorption for total organic carbon control and disinfection byproduct regulation compliance

“…In this study and in others (Arnold et al, 2018; Chuang & Mitch, 2017; Krasner et al, 2016), UFC was used as the chlorination condition in which an incubation time of 24 hr is used. However, THMs and HAAs continue to form after 24 hr, and the Information Collection Rule (ICR) data show that 80% of the utilities estimate their maximum distribution system residence times to be as long as 4 days, which would result in a ~40% increase in TTHM and ~20% increase in HAA5 (Solarik et al, 2000; Summers et al, 1996). Using this continued formation of DBPs after 24‐hr results in target TTHM and HAA5 UFC concentrations of about 60 and 50 μg/L, respectively, to meet the MCLs at 4 days.…”

“…While strong relationships with TOC removal were found, other factors are known to affect DBP formation. The TTHM, HAA5, and HAA9 prediction algorithms, developed for use in the USEPA WTP model and used to support the drinking water DBP Rule development, (Solarik et al, 2000; Swanson, Chowdhury, Summers, & Solarik, 2001), were used to predict the DBP formation under UFC for all treated and untreated WWefs evaluated. These algorithms predict DBP formation as a function of TOC and bromide concentration, UVA, pH, temperature, chlorine dose, and reaction time and have the general form …”

“…A similar approach was taken with the HAA5 data, Figure 6b. To calculate the HAA5 formation, the predicted BCAA concentration is subtracted from the predicted HAA6 concentration (Solarik et al, 2000). The algorithms yield a systematic 16% overprediction, which was likely caused in part by the high bromide to TOC ratios of these wastewater effluents relative to most drinking water sources.…”