title: Photocatalytic Treatment of Desalination Concentrate Using Optical Fibers Coated With Nanostructured Thin Films: Impact of Water Chemistry and Seasonal Climate Variations.
abstract: Treatment of desalination concentrate can reduce concentrate volume for disposal, increase water recovery and convert waste to resource. However, concentrate treatment is costly and energy intensive due to high concentrations of salt and recalcitrant organic matter in concentrate. Photocatalytic oxidation provides a novel energy neutral technology for concentrate treatment by degrading organic contaminants. Polymer-assisted hydrothermal deposition method was used to synthesize innovative pure and Fe-doped TiO2 mixed-phase nanocomposite thin films on side-glowing optical fibers (SOFs). The properties of the photocatalysts-coated SOF were characterized by surface morphology, nanostructure, crystallite size and phase and zeta potential. Photodegradation efficiency and durability of the photocatalysts treating different types of desalination concentrate was studied under natural sunlight. Synthetic solutions and reverse osmosis (RO) concentrates from brackish water and municipal wastewater desalination facilities were tested to elucidate the impact of water chemistry, operating conditions and seasonal climate variations (solar irradiation intensity and temperature) on photocatalytic efficiency. High ionic strength and divalent electrolyte ions in RO concentrate accelerated photocatalytic process, whereas the presence of carbonate species and organic matter hindered photodegradation. Outdoor testing of immobilized continuous-flow photoreactors suggested that the catalyst-coated SOFs can utilize a wide spectrum of natural sunlight and achieved durable photocatalytic performance.
authors.affiliation: Department of Civil Engineering, New Mexico State University, Las Cruces, NM.
authors.forename: Lu
authors.initials: L
authors.lastname: Lin
authors.affiliation: Department of Civil Engineering, New Mexico State University, Las Cruces, NM.
authors.forename: Huiyao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Luo
authors.affiliation: Department of Civil Engineering, New Mexico State University, Las Cruces, NM.
authors.forename: Pei
authors.initials: P
authors.lastname: Xu
mesh_terms: D002384:Catalysis; D002980:Climate; D008567:Membranes, Artificial; D049329:Nanostructures; D055100:Optical Fibers; D009995:Osmosis; D010083:Oxidants, Photochemical; D054712:Salinity; D012621:Seasons; D012965:Sodium Chloride / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D018508:Water Purification
chemical_list: D008567:Membranes, Artificial; D010083:Oxidants, Photochemical; D012965:Sodium Chloride; D062065:Wastewater; D014867:Water