Removal of fluorocarbon contaminations from water

Fluorocarbon contaminates such as perfluorooctane acid or perfluorooctane sulfonate can be found in waste water from several industrial branches, mostly related to the textile industry. The problem arises from textile finishing for oleophobic and hydrophobic properties where fluorocarbons are still without equivalent alternative. Fluorocarbons can be either release during the finishing process itself or off-site the textile industry in reconditioning facilities (laundries), although high efforts are taken to remove the contaminations. One way to remove residual contaminations by plasma processes has been demonstrated in the past by our group for several toxic compounds [1-2]. The use of plasma in contact with water has been shown to be efficient for removal of halogenated compounds (see e.g. [3]). Like in the case of other contaminations, the decontamination efficiency depends on many details in the plasma setup such as gas composition,plasma excitation frequency, electrode and water flow configurations, etc.. In our paper, we present the decontamination from fluorocarbons of artificially contaminated water. Besides the plasma setups, the starting concentrations, gas composition, and aids added to the water were varied. The reduction of the pollutant and the major decomposition products were monitored by 19F NMR. It is shown that the kinetics as well as the final concentrations significantly depends on the removal route. [1] Hijosa-Valsero, M., Molina, R., Schikora, H., Müller, M. and Bayona, J. M.; 2013; Removal of priority pollutants from water by means of dielectric barrier discharge atmospheric plasma; Journal of Hazardous Materials 262; 0; 664-673. [2] Hijosa-Valsero, M., Molina, R., Schikora, H., Müller, M. and Bayona, J. M.; 2013; Removal of cyanide from water by means of plasma discharge technology; Water Research 47; 4; 1701-1707. [3] Karuppiah, J., Reddy, P.M.K., Reddy, E.L., Subrahmanyam, Ch. ; 2013; Catalytic Non-Thermal Plasma Reactor for Decomposition of Dilute Chlorobenzene; Plasma Processes and Polymers 10; 12; 1074–1080.