Photolysis and chromatographic analysis of biphenyl and diphenyl ether mixtures in soil by infrared lamp irradiation

Abstract

To study the environmental behaviors of soil-bound pollutants, it is meaningful to investigate the photolysis of organic pollutants in soil. The pure biphenyl and diphenyl ether mixtures, one of synthetic heat transfer oil, which are the most widely used thermal fluid in solar centrals, were used in this experiment. The photolysis of the mixtures in soil with infrared lamp irradiation were analyzed experimentally using the gas chromatograph. The ultrasonic cleaner was utilized to make the adsorbent gas in the activated charcoal tube dissolved well with analytic agent. The retention time, peak area and peak height was measured by the hydrogen flame ionization detector (FID) technique. The biphenyl and diphenyl ether mixtures can indeed be decomposed by infrared light, although the amount of decomposition was rather small. The results demonstrated that the new substances were various both at different infrared lamp lighting periods and outlets. The proportion between biphenyl and diphenyl ether, of which the mass ratio was no longer 26.5: 73.5, was diverse at different infrared lighting periods and outlets, and the attribution of diphenyl ether to the loss was always higher than that of biphenyl from the analysis of peak area. Based on the chromatographic analysis of condensed liquid mixtures, the decomposition of biphenyl and diphenyl ether mixtures was not only restricted to the time periods of exposure to infrared lamp. The results suggested a reference to prevent soil and groundwater contamination and soil remediation.