Pyrolysis has been identified as a possible thermal treatment process for reducing perfluoroalkyl and polyfluoroalkyl substances (PFAS) from wastewater solids, though off-gas from the pyrolysis unit can still be a source of PFAS emissions. In this work, the fate of PFAS through a laboratory-scale pyrolysis unit coupled with a thermal oxidizer for treatment of off-gasses is documented. Between 91.
View Article and Find Full Text PDFA mathematical model for vacuum evaporation process was developed, which was experimentally validated at different initial pHs and temperatures for ammonia removal from anaerobically digested sludge. Six scenarios were evaluated by combining vacuum evaporation process with anaerobic digestion using anaerobic digestion model 1. These scenarios included a control, a pretreatment by vacuum evaporation, a post-treatment by vacuum evaporation at pH 9, a post-treatment by conventional evaporation (100 °C), an intensification with vacuum-concentrated recycled digestate back to the digester, and a second intensification at pH 9.
View Article and Find Full Text PDFApplication of simultaneous multi-laser nanoparticle tracking analysis (NTA) to environmental water samples to investigate nonliving natural organic matter (NNOM) is introduced as an innovative method for observing particles directly in their native media. Multi-laser NTA results of particle visualization, particle number concentration, and particle size distribution elucidated particle dynamics in low and high total dissolved solids (TDS) aqueous environmental samples. A pond water sample and concentrate from a reverse osmosis (RO) treatment process (Stage 1) had 1.
View Article and Find Full Text PDFPer- and polyfluoroalkyl substances (PFAS) are refractory anthropogenic chemicals and current treatment processes at municipal water resource recovery facilities (WRRFs) cannot efficiently degrade them, hence, these chemicals cycle through the environment. Certain PFAS can be concentrated in biosolids from WRRFs and are commonly land applied for beneficial reuse. Given recent advances in measurement of PFAS, documentation of the range of concentrations in pre-stabilized sludge and stabilized biosolids is critical to evaluating treatment best practices and assessing potential human health and ecological risks.
View Article and Find Full Text PDFPerfluoroalkyl and polyfluoroalkyl substances (PFAS) are an emerging issue in wastewater treatment. High-temperature thermal processes, incineration being time-tested, offer the opportunity to destroy and change the composition of PFAS. The fate of PFAS has been documented through wastewater sludge incinerators, including a multiple hearth furnace (MHF) and a fluidized bed furnace (FBF).
View Article and Find Full Text PDFAn observed decrease in total organic carbon (TOC) and dissolved organic carbon (DOC) concentrations following wastewater disinfection with medium pressure (MP, polychromatic) ultraviolet (UV) irradiation during wet weather flows is investigated. When antecedent rainfall in the previous 7-days was >2 in (5 cm), TOC and DOC concentrations decreased dramatically following MP-UV disinfection. Organic carbon surrogate measurements of biological oxygen demand (BOD), TOC, DOC, turbidity, UVA - 254 nm, SUVA (specific UVA), scanning UV-Visible spectra (200-600 nm), fluorescence excitation-emission matrix (EEM) spectra, and light scattering data are presented for wastewater resource recovery facility (WRRF) influent, secondary effluent (pre-UV-disinfection), and MP-UV-disinfected (final effluent) samples.
View Article and Find Full Text PDFPeriods of drought coupled with increasing population growth have prompted increased interest in potable water reuse in Gwinnett County, Georgia, USA. However, such inland water recycling facilities are challenged with treatment approaches where reverse osmosis (RO) membrane concentrate disposal is a barrier to implementation of potable reuse. To evaluate alternative treatment processes, testing of two side-by-side pilot systems using multi-stage ozone and biological filtration without RO was conducted to compare indirect potable reuse (IPR) to direct potable reuse (DPR).
View Article and Find Full Text PDFSolids from wastewater treatment undergo processing to reduce mass, minimize pathogens, and condition the products for specific end uses. However, costs and contaminant concerns (e.g.
View Article and Find Full Text PDFWastewater treatment generates solids requiring subsequent processing. Costs and contaminant concerns (e.g.
View Article and Find Full Text PDFMeasuring the surrogate parameters total organic carbon and dissolved organic carbon (TOC/DOC) is not adequate, alone, to reveal nuances in organic character for optimizing treatment in potable water reuse. Alternatively, analyzing each organic compound contributing to the surrogate measurement is not possible. As an additional analytical tool applied between these extremes, the use of excitation-emission matrix fluorescence spectroscopy with PARAllel FACtor (EEM-PARAFAC) analysis was investigated in this research to track categories (components) or families of organic compounds during treatment in recycled water schemes.
View Article and Find Full Text PDFPer- and polyfluoroalkyl substances (PFAS) are a recalcitrant group of chemicals and can be found throughout the environment. They often collect in wastewater systems with virtually no degradation prior to environmental discharge. Some PFAS partitions to solids captured in wastewater treatment which require further processing.
View Article and Find Full Text PDFThe Neuse River, North Carolina, U.S., exemplifies a typical de facto potable reuse scenario, where drinking water sources are located downstream of treated wastewater effluent discharges.
View Article and Find Full Text PDFThis study demonstrates differences in sorptive capacity of volatile organic compound (VOC) trichloroethylene (TCE) onto natural organic matter (NOM) coated and uncoated mineral surfaces above and below the NOM glass transition temperature. TCE sorption isotherms for dry NOM-mineral systems below the NOM glass transition temperature (T(g)) demonstrated sorption behavior characteristic of micropore filling, with sorption capacities reduced relative to uncoated mineral matrices. Such differences were not entirely associated with differences in surface areas of the coated and uncoated mineral matrices, but were likely associated with either a blockage of pore space available to the VOC or a kinetic limitation that does not allow the VOC access to the internal porosity of the model soil within the time periods of the experiment.
View Article and Find Full Text PDFResults from an experimental and modeling investigation of the influence of thermodynamic properties of highly purified natural organic matter (NOM) on observed equilibrium sorption/desorption behaviors of vapor phase trichloroethylene (TCE) is presented. Identification of glass transition (T(g)) behavior in Leonardite humic acid and Organosolv lignin enabled evaluation of equilibrium and nonequilibrium sorption behavior in glassy and rubbery NOM. Specific differences in vapor phase equilibrium behavior in NOM above and below their T(g) were identified.
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