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As the demand for sustainable and efficient water treatment solutions grows, the integration of advanced nanomaterials has become a focal point in enhancing membrane technologies. The purpose of this review is to provide a comprehensive and critical analysis of the current state of research on Ti3C2Tx MXenes, highlighting their unique properties, the challenges they address, and the potential they hold for MXene-enhanced biofiltration-membrane systems. The perspective systematically examines how Ti3C2Tx MXenes, with their exceptional electrical conductivity, hydrophilicity, and tunable surface chemistry, can be integrated into biofiltration-membrane systems to improve key performance metrics such as water flux, contaminant rejection, and fouling resistance. Various processes, including biofiltration, adsorption, and nanofiltration, are discussed, where Ti3C2Tx MXenes have been shown to have a potential application. In addition to synthesizing existing literature, experimental validations are presented that demonstrate how MXene incorporation can alter membrane morphology and structure, leading to improved antibacterial properties and enhanced overall performance. These findings underscore the transformative potential of Ti3C2Tx MXenes in developing next-generation biofiltration-membrane technologies that are not only more efficient but also more sustainable. Through this perspective, the key challenges that remain, such as cost implications and long-term stability, are identified, and future research directions are proposed to address these issues. This in-depth analysis highlights the critical role MXenes can play in advancing water treatment technologies, particularly in the context of water reuse, and encourages further interdisciplinary research in this rapidly evolving field. 

Brominated disinfection byproducts (DBPs) are a concern to drinking water utilities due to their toxicity and increasing prevalence in water systems. Haloacetic acids (HAAs) are a class of DBPs that are partially regulated by the United States Environmental Protection Agency (USEPA), but regulations are likely to increase as evidenced by the brominated HAAs listed on the USEPA Fourth Unregulated Contaminant Monitoring Rule and Fifth Contaminant Candidate List. Utilities often use a pre-oxidant to assist in their treatment training, but this can lead to increased HAA formation during treatment. In this study, tap water was spiked with bromine (Br2) at varying concentrations to simulate bromine-to-chlorine ratios found in the natural environment and the DBPs that may be formed from those waters. The water was fed through a bench-scale biological filter (biofilter) with a small layer of fresh granular activated carbon (GAC) media followed by acclimated anthracite media. The HAA species studied were found to be removable by an average of 89.5% through combined GAC filtration and biofiltration. Biodegradation occurred predominantly in the first five minutes for the acclimated anthracite, with minimal additional removal observed at longer empty bed contact times (15 and 30 min EBCT). This study provides recommendations on biofilter parameters for utilities to reduce the formation of both regulated and unregulated HAAs during the drinking water treatment process. 

Seasonal reconstructions of streamflow are valuable because they provide water planners, policy makers, and stakeholders with information on the range and variability of water resources before the observational period. In this study, we used streamflow data from five gages near the Alabama-Florida border and centuries-long tree-ring chronologies to create and analyze seasonal flow reconstructions. Prescreening methods included correlation and temporal stability analysis of predictors to ensure practical and reliable reconstructions. Seasonal correlation analysis revealed that several regional tree-ring chronologies were significantly correlated (p ≤ 0.05) with March–October streamflow, and stepwise linear regression was used to create the reconstructions. Reconstructions spanned 1203–1985, 1652–1983, 1725–1993, 1867–2011, and 1238–1985 for the Choctawhatchee, Conecuh, Escambia, Perdido, and Pascagoula Rivers, respectively, all of which were statistically skillful (R2 ≥ 0.50). The reconstructions were statistically validated using the following parameters: R2 predicted validation, the sign test, the variance inflation factor (VIF), and the Durbin–Watson (D–W) statistic. The long-term streamflow variability was analyzed for the Choctawhatchee, Conecuh, Escambia, and Perdido Rivers, and the recent (2000s) drought was identified as being the most severe in the instrumental record. The 2000s drought was also identified as being one of the most severe droughts throughout the entire reconstructed paleo-record developed for all five rivers. This information is vital for the consideration of present and future conditions within the system.