The salinization of water is increasing from climate change and anthropogenic activity. Seawater intrusion elevates halide concentrations. While chloride and sulfate have aesthetic U.S. secondary maximum contaminant levels of 250 mg/L, halides like bromide and iodide influence disinfection byproduct (DBP) formation. This study examined how disinfection strategy (chlorination, preformed chloramination) affected DBP formation across a 0-30% seawater gradient. During emergencies, many coastal utilities lack alternative sources or blending capacity, making high intrusion levels relevant. In situ chloramination at 0-2% seawater was also investigated. Regulated and unregulated DBP classes were evaluated including, trihalomethanes, haloacetic acids, iodinated trihalomethanes (I-THM) and haloacetic acids, haloacetaldehydes, haloacetonitriles, haloacetamides, and nitrosamines. Relative cytotoxicity was assessed using calculated additive toxicity (CAT). Chlorination produced the highest DBP levels (>400 mu g/L at 8% seawater) and CAT. Trihalomethanes exceeded regulatory limits at all seawater levels under chlorination. Preformed chloramination reduced DBPs and CAT, with no regulatory exceedances. However, I-THM (up to 35 mu g/L) and N-Nitrosodimethylamine (NDMA) formation occurred (up to 19 ng/L). In situ chloramination reduced regulated DBPs, but not enough to meet trihalomethane regulations. Iodinated DBP formation was controlled during in situ, but NDMA levels increased with increasing seawater, surpassing health advisory levels (29 ng/L at 2% seawater).

Disinfection byproducts (DBPs) can transform within building plumbing systems, altering both concentrations and toxicity at the point of use. This study evaluated how pipe material (copper, PEX, PVC), pipe diameter, and water use frequency affect the fate of four regulated trihalomethanes (THM4), nine haloacetic acids (HAA9) and four haloacetonitriles (HAN4) using controlled pipe racks operated for one year under chlorinated and chloraminated conditions. The calculated additive toxicity (CAT) metric for these DBP groups was also evaluated. Random Forest analysis revealed that water use frequency and disinfectant type were the strongest predictors of DBP occurrence and CAT with pipe material and size playing secondary roles. Under low-use conditions, HAN4 concentrations decreased by 60-90%, resulting in a 40-80% reduction in CAT relative to feed water, primarily due to the degradation of nitrogenous DBPs. In contrast, high-use conditions increased CAT by 25-50% across all pipe types. Complementary batch experiments, using copper and PEX pipes, expanded the DBP scope to 52 regulated and unregulated species and showed that, while HANs again declined, overall CAT did not decrease due to elevated levels of unregulated DBPs, particularly haloacetaldehydes which dominated CAT. These findings underscore the limits of relying on regulated DBPs or narrow toxicity metrics and suggest that whole-water assays offer a stronger framework for assessing health risk changes in plumbing systems. The apparent decline in DBP toxicity during stagnation coincided with much higher microbial activity (HPCs) across all pipe materials, emphasizing the challenge of balancing chemical and microbial risks in premise plumbing.

The kinetics of dissolved organic matter removal during coagulation were evaluated using sixteen waters, including two wastewater effluents, across a wide range of water quality (dissolved organic carbon (DOC): 2.10-8.00 mg/L; ultraviolet absorbance at 254 nm (UVA(254)): 0.048-0.211 cm(-1); specific ultraviolet absorbance (SUVA): 1.6-3.08 L/mg & centerdot;m; fluorescence index: 1.40-1.88; turbidity: 1.6-36.5 NTU; pH: 6.5-8.6; alkalinity: 14-128 mg/L-asCaCO3). Jar tests, completely mixed batch reactors (CMBR), assessed coagulation rapid-mixing, flocculation, and sedimentation, while pilot-scale reactors, plug flow reactor (PFR) and completely mixed flow reactor (CMFR), assessed coagulation rapid-mixing kinetics. Baseline CMBR testing included sampling at 1, 5, 10, 20, and 51 min post coagulant addition at 40 mg/L alum and 20 degrees C. Aluminum sulfate, ferric chloride, and ferric sulfate were tested at 10-107 mg/L. As isolated variables, pH (7-8.5), temperature (10-30 degrees C), rapid-mix speeds (55-250 RPM), turbidity (20-120 NTU), and molecular size fractions (<1 kDa and >1 kDa) were varied. Bench-scale CMBR tests (n = 42) showed that 99.1%+/- 8.0% of the DOC uptake occurred within the first minute for all waters and conditions, while the pilot-scale tests yielded 95% (n = 3) DOC uptake within 0.25 min in PFR static mixers and >77% DOC uptake within two min in CMFRs. UVA(254) results yielded similar kinetic results. Additional tests combining powdered activated carbon (PAC) with coagulation showed that DOC removal was unaffected by PAC timing, while early PAC addition enhanced 2-methylisoborneol (MIB) removal. Delaying chlorine addition by 1 min after coagulant addition lowered haloacetic acid and haloacetonitrile formation by 22% and 17%, respectively, but only marginally, 4%, decreased trihalomethane formation.

Direct potable reuse employing reverse osmosis (RO) and advanced oxidation processes (AOP) is emerging as a solution to combat water scarcity in many communities. However, the intermittent passage of low molecular weight (LMW) volatile organic compounds (VOCs) through RO/AOP presents a public health concern. This study assessed two potential add-on treatment strategies: 1) granular activated carbon (GAC) treatment after RO/AOP and 2) ozonation followed by biological activated carbon (O-3/BAC) treatment before RO/AOP. Rapid small-scale column tests (RSSCTs) simulated GAC performance with three intermittent spiking events of individual LMW VOCs-acetone, formaldehyde, methyl tert-butyl ether (MTBE), 1,2-dichloroethane, and 1,2,3-trichloropropane-in RO/AOP product water (50-300 mu g/L). A pilot-scale O-3/BAC system treating tertiary-filtered wastewater was also evaluated under similar spiking conditions. GAC RSSCTs achieved higher reductions of haloalkanes (>98 %), MTBE (>98 %), and acetone (47 %) compared to O-3/BAC. In contrast, formaldehyde was effectively removed by O-3/BAC (>98 %) via biotransformation, while GAC had limited efficacy (<30 %). Spiked VOCs temporarily reduced N-nitrosodimethylamine removal in the O-3/BAC system, but baseline performance recovered. These preliminary results suggest GAC post-RO can mitigate haloalkane and ether-like VOC peaks, although real-world monitoring and long-term pilot testing are needed. O-3/BAC is suited for removing biodegradable compounds like formaldehyde but may require optimization. Additional strategies, such as air stripping, activated sludge pretreatment, and blending, should be further explored to address LMW chemical peaking in potable reuse schemes.

Disinfection byproduct (DBP) formation and transformation in distribution and premise plumbing systems are incompletely characterized, especially in wastewater-impacted waters. We evaluated the impact of pH, Cu2+ addition, and water age on 54 regulated and unregulated DBPs after chlorination of direct potable reuse (DPR) and conventional drinking waters. DPR water produced 1.6× higher DBP and 3.9× higher calculated additive toxicity (CAT) yields than conventional drinking water. Iodinated trihalomethanes (I-THMs) reached 63 μg/L in DPR and 25 μg/L in conventional drinking water. Raising pH to 10 increased trihalomethanes, I-THMs, and dihalogenated haloacetamides but decreased haloacetaldehydes. CAT values decreased with increasing pH, primarily due to base-catalyzed degradation of more toxic DBPs. Cu2+ addition had minimal impact on DBP formation and speciation, except for hindering I-THM formation in both waters and catalyzing trichloroacetaldehyde formation in the conventional drinking water. DBP levels increased over time at pH 7-8 but not at pH 10. CAT declined at pH 7 and remained stable at pH 8-10, indicating that higher water age does not necessarily increase DBP risk. CAT results have the caveat that they are inherently relative; they are intended for comparative purposes between water types and conditions rather than as an absolute measure of risk.

The impact of source water dissolved organic matter (DOM) origin, empty bed contact time (EBCT), temperature, and pretreatment methods on biofiltration performance was evaluated and predictive models based on experimental data were developed. Three DOM source water types, terrestrial, microbial, and treated wastewater (WW) effluent, were utilized. A model was developed to predict biofilter performance for dissolved organic carbon (DOC) removal based on the influent biodegradable DOC (BDOC) fraction, a single active biomass measurement from the top of the filter and the filter EBCT. A biomass distribution model was developed to predict total active biomass throughout the filter based on a single biomass measurement from the top of the filter. The measured BDOC fractions were 21 % for the nonWW impacted source waters, 36 % for the WW effluents and 62 % for the ozonated WW effluents. At an EBCT of 15 min, biofilters removed between 7 and 21 % of the DOC (19 to 50 % for BDOC) depending on the DOM type and use of ozonation. When the EBCT decreased to 5 min DOC removal decreased by 40 % and when increased to 30 min removal increased by 42 %. When the temperature decreased from 22 degrees C to 6 degrees C DOC removal was 33 % lower and when increased to 28 degrees C removal was 42 % higher. ATP values were found to be a function of temperature and DOM origin, as the average ATP values from the WW effluent biofilters were almost double that of the non-WW impacted sources and pre-ozonation of the WW effluent yielded values three times higher. The model was applied to the results of 27 different biofilter runs at three EBCTs yielding one distinct rate constant for the non-WW impacted source waters and one rate constant for the WW effluents. The model was successfully applied to the results of 19 filter runs from the literature and to those from a pilot plant over 6 months of operation.

Disinfection byproduct (DBP) pre-formation is a major issue when prechlorination is used before or during advanced treatment of impacted drinking water sources. Control strategies for pre-formed DBPs before final disinfection, especially for currently nonregulated although highly toxic DBP species, are not yet established. This study evaluated the biodegradation potential of pre-formed DBPs, including haloacetonitriles (HANs), haloacetamides (HAMs), and haloacetaldehydes (HALs), during biofiltration with sand, anthracite, and biological activated carbon of three wastewater effluents under potable reuse conditions. Up to 90%+ removal of di- and trihalogenated HANs, HAMs, and HALs was observed, and removal was associated with active heterotrophic biomass and removal of biodegradable organic carbon. Unlike the microbial dehalogenation pathway of haloacetic acids (HAAs), removal of HANs and HAMs appeared to result from a biologically mediated hydrolysis pathway (i.e., HANs to HAMs and HAAs) that may be prone to inhibition. After prechlorination, biofiltration effectively controlled pre-formed DBP concentrations (e.g., from 271 μg/L to as low as 22 μg/L in total) and DBP-associated calculated toxicity (e.g., 96%+ reduction). Abiotic residual adsorption capacity in biological activated carbon media was important for controlling trihalomethanes. Overall, the toxicity-driving DBP species exhibited high biodegradation potential and biofiltration showed significant promise as a pre-formed DBP control technology.

Increasing the operating temperature has been recommended for controlling opportunistic premise plumbing pathogen (OPPP) growth in buildings. However, tradeoffs with operation and both disinfectant residuals and disinfection byproducts (DBPs) are not well understood. Water heater storage units were operated to evaluate the impact of use pattern (high and low), operation temperature (similar to 45 degrees C and similar to 60 degrees C) and disinfectant type (chlorine and chloramines) on disinfectant residual and DBP concentrations at the showerhead point of use (POU). Control studies with chlorinated water yielded a loss of residual by 72 hours at 22 degrees C and 3 hours at 48 degrees C and 60 degrees C. In the tank heater studies, free chlorine residuals decayed to below the limit of quantitation (LOQ) for all POU samples. The concentrations of total trihalomethanes (TTHMs) and five haloacetic acids (HAA5) at the POU and control sample locations increased by factors of 2.01 +/- 0.21 and 1.46 +/- 0.11, respectively, relative to the feed and peaked at the first point that the chlorine residual was below the LOQ, indicating a chlorine-limited reaction. The TTHM concentrations did not change thereafter, just as the HAA concentrations remained unchanged at 45 degrees C, but the HAA concentrations decreased at 60 degrees C, indicating thermal degradation. Strong decay patterns were found for four haloacetonitriles (HAN4) at elevated temperatures, and the decay was faster at 60 degrees C. In the chloramination system, total chlorine decreased passing through the tank, but a detectable residual was measured in all samples. No additional DBP formation relative to the feed was found. Under all scenarios, there was no indication of a tradeoff between controlling OPPPs and DBP formation when increasing the operating temperature to 60 degrees C. The concentrations of TTHM and five HAA5 at the POU and control sample locations increased relative to the feed. Strong decay patterns were found for haloacetonitriles at elevated temperatures, and the decay was faster at 60 degrees C compared to 45 degrees C.

For the potable reuse of municipal wastewater effluent, carbon based advanced treatment (CBAT) using coagulation, ozonation, biofiltration and/or granular activated carbon (GAC) adsorption is a promising approach for controlling disinfection byproduct (DBP) formation. However, CBAT can also favor a shift in DBP formation to more toxic brominated DBP species. To protect public health, treatment-specific DBP formation and speciation trends need to be identified and understood. First, this study systematically evaluated the treatment of six wastewater effluents with four CBAT process trains (experimental n was 55) and measured DBP formation and speciation trends. Overall, CBAT decreased DBP formation by >90% and GAC preferentially removed highly-reactive effluent organic matter as indicated by lower yields of both highly-forming and highly-toxic classes of carbonaceous and nitrogenous DBPs. Since GAC treatment also induced systematic speciation changes by increasing the ratio of bromide to dissolved organic matter, the second part of this study focused on understanding the health impacts of DBP speciation changes on calculated additive toxicity (CAT). Based on the evaluation of 20 DBPs, measured using established methods, the CAT values from cyto- and genotoxicity metrics decreased by as much as 85% due to high levels of precursor removal by GAC. Expanding the evaluation to include 52 DBPs, measured using more extensive analytical methods, resulted in the same conclusions. This study also developed a "speciation potency" metric, that re-scales class-by-class speciation trends using toxic potency factors (e.g., cytotoxicity [LC50]). The observed shifts in DBP speciation after treatment increased the class-level toxic potency factors by up to a factor of 4; a greater amount of precursor removal is required for treatment to reduce toxicity, which was achieved with CBAT trains. This proposed approach of combining speciation potency with DBP yields enables evaluation of DBP-associated risk with easily measured surrogates (i.e., bromide and dissolved organic carbon [DOC]). By identifying and quantitatively comparing DBP formation and speciation trends over multiple wastewater effluents and treatment trains, this study demonstrates that CBAT can be a robust approach to DBP precursor removal for potable reuse.

Biochars were produced from pine feedstock pretreated with aqueous base, NaOH, at pH 9 and 11, and alkali and alkaline earth metals (AAEMs) Na, K, Ca, and Mg at 10(-3) and 1 M. The effects of base and AAEM feedstock pretreatment on biochar surface area, pore size distribution, and adsorption capacity of two organic micro pollutants (OMPs), 2,4-dichlorophenoxyacetic acid and sulfamethoxazole, from surface water with background dissolved organic matter (DOM) were evaluated. Base pretreatment significantly increased surface area within micropores (<2 nm diameter). AAEM pretreatment caused pore widening, increasing surface area within pores >2 nm in diameter. The catalytic activity of AAEMs, assessed by generation of non-micropore surface area, decreased in the following order: Ca > K > Na > Mg. All pretreated biochars outperformed untreated biochar for OMP adsorption. Biochar pretreated by aqueous base at pH 11 showed over an order of magnitude increase in OMP adsorption, nearly matching the performance of commercial activated carbon. OMP adsorption from surface water was positively correlated with biochar micropore surface area and negatively correlated with nonmicropore surface area, which was linked to higher levels of DOM competition. Base and AAEM pretreatment of biochar feedstocks can increase OMP adsorption for water treatment applications by tuning pore structure and surface area.

Adsorption of perfluoroalkyl acids (PFAAs) by granular activated carbon (GAC) was evaluated in bench‐, pilot‐, and full‐scale studies to determine effects of PFAA characteristics and background organic matter on carbon use rates. Rapid small‐scale column tests (RSSCTs) were conducted according to the proportional diffusivity (PD) design to assess their suitability to predict full‐ or pilot‐scale GAC performance. PFAA removal from groundwater (GW) and coagulated surface water (SW) was studied with two sub‐bituminous coal‐based GACs. In batch tests conducted with pulverized GAC, the GACs performed similarly in GW, but the GAC with the larger mesopore volume was more effective for PFAA removal from SW. In column tests, carbon use rates decreased with increasing PFAA chain length and were lower for GW (total organic carbon [TOC] = 0.7 mg/L) than for SW (TOC = 2.0–2.7 mg/L). The volume of SW that could be treated to 10% or 50% PFAA breakthrough was about 50–60% of the volume of GW that could be treated when comparing pilot‐scale data for SW with full‐scale data for GW. Consistent differences in PFAA adsorption capacity were not observed for empty bed contact times of 13 and 26 min in full‐scale adsorbers treating GW. The PD‐RSSCT simulating PFAA removal from GW consistently overpredicted full‐scale adsorption capacity, on average by ~70%. Using a carbon use rate of <25 mgGAC/Lwater treated) as a criterion for the feasibility of GAC treatment, full‐ and pilot‐scale GAC adsorber data suggest that GAC is a viable treatment option (carbon use rate < 25 mgGAC/Lwater treated) for perfluoroalkylcarboxylic acids with six or more carbon atoms in SW and five or more carbon atoms in GW. For perfluoroalkyl sulfonic acids, GAC treatment is viable for compounds containing four or more carbons based on results obtained with both SW and GW.

Biofiltration, historically used for biodegradable organic matter (BOM) removal in drinking water treatment, is being increasingly applied for potable reuse which requires unique characterization. This review and meta-analysis evaluates BOM occurrence as part of bulk wastewater effluent organic matter (EfOM), quantifies the roles of operational parameters to achieve EfOM removal in biofilters, and identifies research gaps which may be fruitful for understanding reuse biofilter performance. Literature data ( n = 76) indicates EfOM has a high biodegradable fraction (median 26%), which after typical ozone doses is higher (57%). A biofiltration performance dataset ( n = 160 across 42 WWTP effluents) shows that EfOM removal of 35-40% can be expected when design parameters are optimized. Specifically, higher EfOM removal is achieved by adding pre-ozonation and use of biological activated carbon (BAC) media, with comparatively smaller impacts of increasing ozone dose or increasing empty bed contact time under typical scenarios. Combined, these factors strongly correlate with observed EfOM removal ( r 2 = 0.64) after accounting for confounding by adsorptive removal in BAC media with fewer than 20,0 0 0 bed volumes treated. Future research that quantifies the occurrence of BOM, biomass activity on filter media, steady-state removal by BAC, and impacts of longer empty bed contact times in potable reuse scenarios could impact optimization strategies to meet or exceed biofilter performance observed to date. (c) 2021 Elsevier Ltd. All rights reserved.

A novel powdered ash-treated pine biochar (PATB) was compared to powdered activated carbon (PAC) for the removal of dissolved organic matter (DOM) and organic micropollutants (OMPs) from deionized water (DI), raw surface water (SW), and treated wastewater (WW). PATB performance (capacity and kinetics) was the primary focus under realistic water treatment adsorbent doses (<200 mg/L) and contact times (<120 min). For the removal of DOM, iohexol (IOH), sucralose (SUC), and sulfamethoxazole, PAC consistently outperformed PATB. For the more readily adsorbable OMPs carbamazepine, cotinine, DEET, and theobromine, removal by the two adsorbents was comparable. Dose-response and kinetic results for each adsorbent between SW and WW for DOM, IOH, and SUC were similar, as their initial dissolved organic carbon concentrations were diluted to the same range: 2.0-2.2 mg/L. SUC was found to have a higher affinity for PATB in DI, but ultimate removal was still limited by its lower specific surface area compared to PAC (similar to 500 versus similar to 1,000 m(2)/g). Additional investigations included combined adsorbent treatment and projecting batch results to fixed-bed breakthrough curves for hypothetical full-scale granular activated carbon and granular ash-treated biochar adsorbers using both the homogeneous surface diffusion model and pore and surface diffusion model. (C) 2021 American Society of Civil Engineers.

Biochar adsorbent can be produced in low-resource settings using local materials and simple pyrolysis technology, and it has shown promise for uptake of micropollutants (MPs) such as pesticides, pharmaceuticals, industrial compounds, and chemicals released from consumer goods present in water at ng/L to mu g/L levels. Accordingly, the use of biochar in water treatment applications where granular activated carbon (GAC) is economically or logistically infeasible is gaining interest. Monitoring treatment systems for individual MPs require laboratory analytical techniques that are typically cost-prohibitive and impractical for low-resource settings. Therefore, identification of surrogate parameters(s) for adsorbent bed life that can be measured inexpensively and in the field is a high priority. Background dissolved organic matter (DOM) is ubiquitous in natural and anthropogenic waters at concentrations typically 1,000 to 100,000 that of MPs. Some constituents of DOM foul the adsorbent and reduce bed life for removal of target contaminants. Aromatic DOM foulants absorb ultraviolet light at a wavelength of 254 nm (UVA(254)). Because DOM fouling directly affects MP adsorption capacity and DOM is a bulk water parameter that can be quantified using relatively inexpensive and portable instruments, it could be exploited as a surrogate for monitoring biochar adsorber bed life under field conditions. The objective of this study was to quantify removal of MPs from waters containing different types and concentrations of background DOM (surface water, wastewater, dump leachate) and thus exhibiting different UVA(254) breakthrough profiles in bench-scale column experiments. Breakthrough profiles of weakly to moderately adsorbing MPs, including herbicides, pharmaceuticals and personal care products, and perfluoroalkyl acids, were collected using biochars generated under different pyrolysis conditions and a commercial GAC as a performance benchmark. Optimal conditions for biochar water treatment include using biochar produced from wood at >= 850 degrees C under slightly aerobic conditions, empty bed contact times of >= 30 min, and upstream treatment processes to reduce DOM. Relative UVA(254) breakthrough (C/C-0) up to 0.6-0.9 corresponded to >= 90% MP removal for most MP-water combinations studied.

Previous studies have shown that algal-derived dissolved organic matter (DOM) has a strong influence on the formation of disinfection byproducts (DBPs) during the treatment of drinking water. In the summer of 2010, we evaluated the role of nitrogen and phosphorus loading and phytoplankton abundance as drivers of the concentrations and quality of DOM and the associated DBP formation in 30 reservoirs in the mountains and plains of the State of Colorado. Optical properties such as Specific Ultraviolet Absorbance at 254 nm (SUVA 254 ) and fluorescence spectroscopy were used to characterize DOM quality. Nutrient concentrations such as total nitrogen were also assessed and were associated with high concentrations of chlorophyll a (Chl-a). In turn, high total organic carbon (TOC) concentrations were associated with high concentrations of Chl-a, and the DOM in these reservoirs had a fluorescence signature indicative of contributions from phytoplankton growth. The reservoirs with TOC concentrations above 4 mgC/L were predominantly located in the plains and many are impacted by agricultural runoff and wastewater discharges, rather than in the mountains and are characterized by warm water conditions and shallow depths. For a subset of fourteen reservoirs, we characterized the composition of the phytoplankton using a rapid imaging microscopy technique and observed a dominance by filamentous Cyanobacteria in reservoirs with TOC concentrations above 4 mgC/L. The combination of high TOC concentrations with microbial characteristics resulted in high potential for production of two major classes of regulated DBPs, trihalomethanes and haloacetic acids. While fluorescence spectroscopy was useful in confirming the contribution of phytoplankton growth to high TOC concentrations, evaluation of predictive models for DBP yields found that all equally predictive models included SUVA 254 and some of these models also included fluorescence indices or logTOC. These findings provide a limnological context in support of the recent guidelines that have been implemented for protection of high-quality drinking water supplies in the State of Colorado.

For high levels of TrOC removal by GAC, reducing DOC 0 concentration is more important than the specific DOM removal pretreatment process.

Almost half of the world’s population is living without access to sanitation services that are safe, reliable, and minimize public health risk of human waste exposure. Modern flush-based sanitation networks are unsustainable: substantial resources, namely water and fuel, are required to bring human waste to centralized treatment facilities. Moving toward sustainable sanitation requires the implementation of innovative renewable energy technologies for stabilization and disinfection of waste, at the local or household scale, where minimal inputs of water, electricity or chemicals are required. A novel solar thermal disinfection toilet prototype has been constructed and is assessed for overall solar to receiver efficiency in treating waste without electrical, chemical, or water inputs from municipal supply. The measured solar to receiver efficiency is 28%, incorporating the capturing and concentration of sunlight and transmission of the energy to the receiver. For a typical sunny day, the current system can achieve thermal treatment of 0.8 kg human waste in roughly 100 min. The novel toilet is available for any location in the world with sufficient sunlight and irradiance data, and is scalable by adding solar collectors for sizes from single dwellings to communities.

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.