Treatment of toluene and xylene compounds from wastewater using air stripping and non thermal plasma system
Loading...
Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Teknologi Malaysia
Abstract
The limitations of the conventional methods in the treatment of volatile organic compounds such as toluene and xylene from wastewater have led to researches into the application of non-thermal plasma technology as an alternative treatment method. The application of this technology as an integrated system comprising air stripping and non-thermal plasma reactor in the treatment of toluene and xylene from wastewater coupled with online Fourier transform infrared spectroscopy (FTIR) as a by-product detection technique were studied. The toluene and xylene rich air stream from the air stripper was directly fed to the non-thermal plasma reactor system. The performance of the integrated system was evaluated at various experimental conditions. The modelling and optimization of applied voltage, discharge gap and gas flow rate on the non-thermal plasma decomposition of toluene and xylene as well as the decomposition by-products determined from the FTIR spectra were also carried out. It was found that toluene and xylene removal efficiencies from air stripping increased non-linearly with temperature and air-water ratio in which at 50 °C and air-water ratios of 100, 93% removal efficiency for both toluene and xylene was obtained. The decomposition of toluene and xylene in nonthermal plasma reactor was found to be significantly influenced by the applied voltage, discharge gap and gas flow rate in which the developed models showed a good fit with coefficient of correlations of 89.38% and 92.76% for the toluene and xylene respectively. The optimum discharge gap, applied voltage and flow rate for the decomposition of toluene and xylene in non-thermal plasma reactor were 22.3 mm, 15 kV, 3.56 L/min; and 20.1 mm, 15 kV, 3.34 L/min for toluene and xylene, respectively. At this optimized conditions, the equivalent predicted toluene and xylene removal efficiencies of 87 and 82% having 1.3 and 2.2% errors were obtained respectively. The by-products determination by online FTIR indicated that water, carbon dioxide, carbon monoxide and nitrous oxide gases were detected. These findings generally confirm the compatibility of the integrated system and its suitability towards the treatment of volatile organic compounds from wastewater.
Description
Thesis (PhD. (Chemical Engineering))
Keywords
Sewage—Purification—Organic compounds removal, Sewage—Purification—Technological innovations, Plasma chemistry