Optical fiber detector for monitoring volatile hydrocarbons during electrokinetic treatment of polluted soil

Abstract

BACKGROUND This work proposes an optical fiber sensor to monitor the presence of volatile organic compounds (VOCs). The sensor consists of a single‐mode fiber 1 cm long, coated with a composite of Prussian blue and an acrylic polymeric emulsion, inserted between two multimode fibers. RESULTS The presence of VOCs modifies the optical properties of the composite layer and produces attenuation changes of the evanescent field. These attenuation changes can be easily monitored by a simple experimental set‐up. The fabrication of the sensor is very simple which makes this sensor very attractive. The fabricated sensor was tested with three different VOC gases, acetone, isopropyl alcohol and chloroform. The response of the sensor was different for each gas, but in all cases the regression analysis was linear. CONCLUSION It was demonstrated that this VOC sensor can be used to detect volatile hydrocarbons, generated or forced to migrate from the solid phase (soil) to the gas phase (air) during the application of electrokinetic treatment to the polluted soil or in the environment. © 2016 Society of Chemical Industry

Relevance of gaseous flows in electrochemically assisted soil thermal remediation

“…Nonetheless, they are becoming key tools for the evaluation of full-scale remediation actions and, nowadays, more and more exigent models are being developed. A very interesting point worth to be highlighted is the modeling of the gaseous flows generated during the electrochemically assisted treatment, because these gaseous streams need to be properly collected and treated to reach an efficient and holistic treatment in the remediation of soils polluted with VOCs [53]. Many processes should be considered, including the formation and release of gas bubbles, the interaction of these bubbles with the soil and the potential occurrence of heterogeneous chemical reactions [10].…”