DOI: 10.1016/j.watres.2018.12.065
Scopus记录号: 2-s2.0-85060255242
论文题名: Synergistic removal of ammonium by monochloramine photolysis
作者: Zhang X. ; Ren P. ; Li W. ; Lei Y. ; Yang X. ; Blatchley E.R. ; III
刊名: Water Research
ISSN: 431354
出版年: 2019
起始页码: 226
结束页码: 233
语种: 英语
英文关键词: Ammonium
; Kinetic model
; Reactive chlorine radicals
; UV/NH 2 Cl process
Scopus关键词: Biological materials
; Chlorine
; Degradation
; Dimers
; Disinfection
; Efficiency
; Irradiation
; Photodegradation
; Photolysis
; Potable water
; Rate constants
; Water treatment
; Ammonium
; Chlorine radicals
; Drinking water production
; Kinetic modeling
; Natural organic matters
; Nitrogenous disinfection by-products
; Pseudo first order rate constants
; Second-order rate constants
; Chlorine compounds
; ammonia
; bicarbonate
; chloride
; chlorine
; drinking water
; hydroxyl radical
; monochloramine
; natural organic matter
; ammonium
; chlorine
; disinfection
; drinking water
; inhibition
; irradiation
; organic nitrogen compound
; photolysis
; pollutant removal
; radical
; reaction kinetics
; reaction rate
; scavenging (chemistry)
; synergism
; ultraviolet radiation
; water treatment
; Article
; chemical reaction kinetics
; concentration at steady-state
; controlled study
; decomposition
; degradation
; kinetics
; pH
; photochemistry
; photolysis
; priority journal
; rate constant
; ultraviolet irradiation
英文摘要: The presence of ammonium (NH 4 + ) in drinking water treatment results in inhibition of disinfection efficiency and formation of nitrogenous disinfection by-products. Our previous study found monochloramine (NH 2 Cl) photolysis under 254 nm UV irradiation can be effective for removal of NH 4 + ; however, the mechanisms of NH 4 + degradation in this process were unknown. The kinetics and fundamental radical chemistry responsible for NH 4 + removal in the UV/NH 2 Cl process were investigated in this study. The results showed that the pseudo first-order rate constant for NH 4 + degradation in the UV/NH 2 Cl process ranged between 3.6 × 10 −4 to 1.8 × 10 −3 s −1 . Solution pH affected radical conversion and a higher NH 4 + degradation efficiency was achieved under acidic conditions. The effects of chloride were limited; however, the presence of either bicarbonate or natural organic matter scavenged radicals and inhibited NH 4 + removal. NH 2 Cl photolysis generated an aminyl radical (NH 2 • ) and a chlorine radical (Cl • ) that further transformed to a chlorine dimer (Cl 2 •- ) and a hydroxyl radical (HO • ). The second-order rate constants for Cl • and Cl 2 •- reacting with NH 4 + were estimated as 2.59 × 10 8 M −1 s −1 and 3.45 × 10 5 M −1 s −1 at pH 3.9, respectively. Cl • , Cl 2 •- , and HO • contributed 95.2%, 3.5%, and 1.3% to NH 4 + removal, respectively, at the condition of 3 mM NH 2 Cl and pH 7.5. Major products included nitrite and nitrate, possibly accompanied by nitrogen-containing gases. This investigation provides insight into the photochemistry of NH 4 + degradation in the UV/NH 2 Cl process and offers an alternative method for drinking water production. © 2019 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122001
Appears in Collections: 气候变化事实与影响
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作者单位: School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, 510275, China; Guangzhou Municipal Engineering Design & Research Institute, Guangzhou, 510060, China; School of Municipal and Environmental Engineering, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China; Lyles School of Civil Engineering, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051, United States; Division of Environmental & Ecological Engineering, Purdue University, West Lafayette, IN 47907-2051, United States
Recommended Citation:
Zhang X.,Ren P.,Li W.,et al. Synergistic removal of ammonium by monochloramine photolysis[J]. Water Research,2019-01-01