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

Abstract

The widespread and successful use of coagulation, ozonation, biofiltration, and granular activated carbon (GAC) adsorption for the treatment of impaired drinking water sources makes them attractive as an economical approach for direct potable reuse. This study systematically evaluated these processes for the treatment of four secondary wastewater effluents with the objective of meeting U.S. drinking water disinfection byproduct (DBP) regulations and developing treatment objectives. Total trihalomethane (TTHM) and the sum of five haloacetic acids (HAA5) targets of 60 and 50 μg/L, respectively, were developed under uniform formation conditions and were related to a target total organic carbon (TOC) concentration of 2 mg/L. Ozonation, followed by biofiltration, was effective in decreasing HAA5 formation to below the target levels, but GAC treatment was needed to meet the target TTHM and TOC levels. Optimizing the TOC removal before GAC treatment extended the GAC run times similarily to those found in drinking water treatment. Drinking water–based DBP formation algorithms were very effective in predicting TTHM and HAA5 formation.

Biodegradable dissolved organic carbon profiling reveals capacity of carbon‐based potable reuse treatment over a range of operating conditions

“…However, since upstream BAC performance was improved by EBCT, this resulted in a greater percent removal of the remaining DOC during GAC contacting. This highlights the importance of optimizing upstream BAC filtration to maximize GAC contacting (Summers et al, 2020) and hypothetically prolong its operational lifespan. Still, the remaining organic carbon in the GAC10 and GAC20 effluents were 29% and 22% BDOC, respectively, indicating that there is still potential for biofouling and microbial regrowth in the final water (de Vera & Wert, 2019; Escobar & Randall, 2001; Joret et al, 1991; Thayanukul et al, 2013; van der Kooij, 1992).…”

A relationship between phages and organic carbon in wastewater treatment plant effluents

“…Disinfection by chlorination is used as the final treatment step at WWTPs around the world. The presence of DOC would increase the chlorine consumption and lead to the formation of toxic byproducts ( Summers et al., 2020 ). Managing the DOC content in WWTP effluents is, therefore, an important challenge.…”

Adsorption Studies of Waterborne Trihalomethanes Using Modified Polysaccharide Adsorbents

“…A comparison of the adsorption capacity for AC with the PS adsorbents is summarized in Table 6. The relevance of comparing the uptake results for AC with the copolymers relate to the widespread use of AC as an industrial carbonaceous adsorbent for THMs removal [3,[11][12][13]15,16]. The adsorption isotherms of AC (cf.…”

“…Chlorination efficiently reduces microbial pathogen levels in water supplies and the incidence of waterborne diseases. An unintended consequence of the disinfection process results in the formation of disinfection by-products (DBPs) for water that contains dissolved organic carbon (DOC) [2,3]. Trihalomethanes (THMs) are among the most common and important DBPs, which pose a potential public health concern as a result of conventional water disinfection processes.…”