title: Study of different methods for enhancing the nitrate removal efficiency of a zero-valent metal process.
abstract: This study explores the effect of several enhancing methods, namely acid wash pretreatment, ultrasound treatment and addition of nickel catalyst on the nitrate removal efficiency of three zero-valent metals--iron, aluminium and zinc. It is hoped that by learning about the major reaction pathways of nitrate removal with zero-valent metals and the main factors influencing the reactivity of those zero-valent metals, optimum process conditions may be identified. The study results show that direct transfer of electrons is the major reaction pathway. Thus increasing a clean, fresh metal surface and decreasing the thickness of the diffusion layer to accelerate mass transfer are the main determinants of reaction rate. In the absence of a clean, fresh metal surface, the catalytic reaction of nickel becomes the primary removal pathway.
authors.affiliation: Department of Environmental Engineering and Management, Chaoyang University of Technology, Wufeng, Taiwan. shufen@mail.cyut.edu.tw
authors.forename: S F
authors.initials: SF
authors.lastname: Cheng
authors.forename: C Y
authors.initials: CY
authors.lastname: Huang
authors.forename: J Y
authors.initials: JY
authors.lastname: Liu
mesh_terms: D000535:Aluminum / Q000737:chemistry; D002384:Catalysis; D004058:Diffusion; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D008670:Metals / Q000032:analysis* / Q000737:chemistry*; D019216:Metals, Heavy; D009566:Nitrates / Q000032:analysis*; D009584:Nitrogen / Q000737:chemistry; D014465:Ultrasonics; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*; D015032:Zinc / Q000737:chemistry
chemical_list: D007220:Industrial Waste; D008670:Metals; D019216:Metals, Heavy; D009566:Nitrates; D014874:Water Pollutants, Chemical; D000535:Aluminum; D007501:Iron; D015032:Zinc; D009584:Nitrogen