1. Catalytic ozonation of organic pollutants from bio-treated dyeing and finishing wastewater using recycled waste iron shavings as a catalyst: Removal and pathways.
- Author
-
Wu J, Ma L, Chen Y, Cheng Y, Liu Y, and Zha X
- Subjects
- Adsorption, Biodegradation, Environmental, Biological Oxygen Demand Analysis, Catalysis, Chemical Precipitation, Chromatography, High Pressure Liquid, Corrosion, Electron Spin Resonance Spectroscopy, Gas Chromatography-Mass Spectrometry, Molecular Weight, Recycling, Spectrometry, Fluorescence, Waste Disposal, Fluid, Coloring Agents chemistry, Industrial Waste analysis, Iron chemistry, Organic Chemicals isolation & purification, Ozone chemistry, Wastewater chemistry, Water Pollutants, Chemical chemistry
- Abstract
Catalytic ozonation of organic pollutants from actual bio-treated dyeing and finishing wastewater (BDFW) with iron shavings was investigated. Catalytic ozonation effectively removed organic pollutants at initial pH values of 7.18-7.52, and the chemical oxygen demand (COD) level decreased from 142 to 70 mg·L(-1) with a discharge limitation of 80 mg·L(-1). A total of 100% and 42% of the proteins and polysaccharides, respectively, were removed with a decrease in their contribution to the soluble COD from 76% to 41%. Among the 218 organic species detected by liquid chromatography-mass spectrometry, 58, 77, 79 and 4 species were completely removed, partially removed, increased and newly generated, respectively. Species including textile auxiliaries and dye intermediates were detected by gas chromatography-mass spectrometry. The inhibitory effect decreased from 51% to 33%, suggesting a reduction in the acute toxicity. The enhanced effect was due to hydroxyl radical (OH) oxidation, co-precipitation and oxidation by other oxidants. The proteins were removed by OH oxidation (6%), by direct ozonation, co-precipitation and oxidation by other oxidants (94%). The corresponding values for polysaccharides were 21% and 21%, respectively. In addition, the iron shavings behaved well in successive runs. These results indicated that the process was favorable for engineering applications for removal of organic pollutants from BDFW., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF