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1,0x10
7 8,0x10
7 6,0x10
4,0x107
7 2,0x10
F=1.5L/min, t=1min, d=2cm
5,5x10 5,0x106 4,5x106
6 4,0x10
3,5x106 3,0x106 2,5x106 2,0x106 1,5x106 1,0x106
5 5,0x10
0,0
P= 50W, t= 1min, d =2cm
0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,2
Gas flow (l/m)
1,6x107
7 1,4x10
7 1,2x10
1,0x107
6 8,0x10
6,0x106
4,0x106
6 2,0x10
0,0
P=50W, F=1.5 L/min, d=2cm
0,81,01,21,41,61,82,02,22,42,62,8
Time (min.)
6x10 5x106 4x106
6 3x10
2x106
6 1x10
0
P=50W,t=1min,F=1.5L/minde
Clean Environment
possible to increase the oxidation and water treatment capacity of plasma with increasing values of these parameters: power, gas flow and treatment time. Different behavior was found for the dependence on the distance between sample and plasma. In this case, an optimum distance has been found around 2.5 cm, where highest concentration of oxidation products is found.
The xylene oxidation is due to the generation of OH radicals. Presence of this radical in post discharge has been confirmed by fluorometric measurements of 7-Hydroxycoumarin Carboxylic acid produced from plasma treatment of a solution 0.003M 3-Coumarin Carboxylic acid in miliQ water.
In conclusion, this work shows that a non-thermal microwave plasma is a useful medium to the treatment of water contaminated with xylene, due to the oxidation produced by OH radicals from the plasma activation. The study of dependence of this oxidation on experimental conditions allows us to have a best knowledge of its future application to industrial scale..
866
Tolualdehyde
2,3-Xylenol
2,6-Xylenol
Tolualdehyde
2,3-Xylenol
2,6-Xylenol
Tolualdehyde
2,3-Xylenol
2,6-Xylenol
Tolualdehy
2,3-Xylenol
2,6-Xylenol
0,0
20 30 40 50 60 70 80 90 100
Power (W)
0 1
2 3
Distance (cm)
4 5
Fig. 2: Dependence of intensity of chromatographic peaks on microwave power, argon gas flow, treatment time and distance plasma-sample.
4. Acknoledgements
Authors thank the European Regional Development Funds program (EU-FEDER) and the MINECO (project MAT2016-79866-R) for financial support. The authors also are grateful to the funding offered by the Polish National Agency for Academic Exchange as part of the Academic International Partnerships (project PPI/APM/2018/1/00033/U/001)
5. References
Moisan M., Pelletier J. (1992), Microwave excited plasmas, Plasma Technology, Elsevier, Amsterdan. (Chap.3). Newton G.L., Milligan J.R. (2006), Fluorescence detection of hydroxyl radicals, Radiation Physics and Chemistry,
75, pp 473-748.
Zhao J., Zhang R., Misawa K., Shibuya, K. (2005), Experimental product study of the OH-initiated oxidation of m-
xylene, Journal of Photochemistry and Photobiology, 176, pp 199-207.
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Intensity (u.a.)
Intensity (u.a)
Intensity (u.a.)
Intensity (u.a.)