Research on Mechanism and Pathway of p-CNB Degraded by Ultrasound/Fe0
The degradation of p-chloronitrobenzene by zero-value-iron concurrent ultrasound was investigated at an initial p-CNB concentration 0.1 mmol/L and iron powder 2.5 g/L. The experimental data indicated that the optimal pH is 3 over the range of initial pH 3-9. It indicated that the iron powder corrodes rapidly in the acidic condition. The degradation rates were compared with in three systems, (1) ultrasound only; (2) iron powder only; (3) iron powder in the present of ultrasound. It was observed that p-CNB degradation was enhanced in US/Fe0 system. These result suggested that the rate enhancements in US/Fe0 system were attributed to (1) the continuous cleaning and activation of the iron powder surface by the chemical and physical effects of ultrasound; (2) accelerating mass transfer rates of reactants, intermediates, and products between the solution phase and the iron powder surface. The p-CNB degradation intermediate products were analyzed by gas chromatography-mass spectrometry. The main intermediate products were p-chloroaniline, p-chloronitrosobenzene and 4, 4-dechloro -oxidated-azobenzene. From the identified reaction products, a possible degradation pathway has been proposed and the possibility was explained with quantum chemical theory. It also been discussed for the generating of the byproduct 4, 4-dechloro-oxidated-azobenzene.
Ultrasonic iron powder p-chloronitrobenzene degradation pathway
TIAN Kaixun DAI Youzhi
Department of Environmental Engineering,Xiangtan University,Xiangtan 411105,Hunan,China
国际会议
2009 International Symposium on Environmental Science and Technology(2009环境科学与技术国际会议)
上海
英文
1512-1515
2009-06-02（万方平台首次上网日期，不代表论文的发表时间）