title: Organic acids enhanced decoloration of azo dye in gas phase surface discharge plasma system.
abstract: A gas phase surface discharge plasma combined with organic acids system was developed to enhance active species mass transfer and dye-containing wastewater treatment efficacy, with Acid Orange II (AO7) as the model pollutant. The effects of discharge voltage and various organic acid additives (acetic acid, lactic acid and nonoic acid) on AO7 decoloration efficiency were evaluated. The experimental results showed that an AO7 decoloration efficiency of approximately 69.0% was obtained within 4 min of discharge plasma treatment without organic acid addition, which was improved to 82.8%, 83.5% and 88.6% within the same treatment time with the addition of acetic acid, lactic acid and nonoic acid, respectively. The enhancement effects on AO7 decoloration efficiency could be attributed to the decrease in aqueous surface tension, improvement in bubble distribution and shape, and increase in ozone equivalent concentration. The AO7 wastewater was biodegradable after discharge plasma treatment with the addition of organic acid. AO7 decomposition intermediates were analyzed by UV-vis spectrometry and GC-MS; 2-naphthol, 1,4-benzoquinone, phthalic anhydride, coumarin, 1,2-naphthoquinone, and 2-formyl-benzoic acid were detected. A possible pathway for AO7 decomposition in this system was proposed.
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, PR China. Electronic address: wangtiecheng2008@126.com.
authors.forename: Tiecheng
authors.initials: T
authors.lastname: Wang
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, PR China.
authors.forename: Guangzhou
authors.initials: G
authors.lastname: Qu
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, PR China.
authors.forename: Jingyu
authors.initials: J
authors.lastname: Ren
authors.affiliation: Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Sun
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, PR China.
authors.forename: Dongli
authors.initials: D
authors.lastname: Liang
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, PR China.
authors.forename: Shibin
authors.initials: S
authors.lastname: Hu
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D055664:Electrochemical Techniques; D009281:Naphthalenes / Q000737:chemistry*; D058626:Plasma Gases; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: C456587:Acid Orange II; D001391:Azo Compounds; D002264:Carboxylic Acids; D009281:Naphthalenes; D058626:Plasma Gases; D014874:Water Pollutants, Chemical
keywords: Acid orange; Decoloration; Organic acids; Surface discharge plasma