화학공학소재연구정보센터
Chemical Engineering Journal, Vol.337, 567-575, 2018
Complete mineralization of organic pollutants in water by treatment with air non-thermal plasma
The first result of complete mineralization of organic pollutants in water treatment by a plasma-based advanced oxidation process is reported. A dielectric barrier discharge reactor was used to study the effects of the pollutant initial concentration on the process rate and on the extent of mineralization. Using phenol as a model pollutant extensive product studies and carbon mass balance were performed with an integrated analytical approach. Notably, the concentrations of phenol and of its major oxidation intermediates were determined at different treatment times by means of HPLC/UV-Vis and ion chromatography. In addition, the CO2 released from the solution during the process and the residual total carbon in solution after the treatment were also determined by in line FT-IR analysis of the air flowing out of the reactor and by Total Carbon analysis of the liquid, respectively. Under fixed plasma conditions, both the process rate and the extent of mineralization increase as the pollutant initial concentration is decreased. Complete mineralization was achieved for 1.10(-5) M phenol, a very encouraging result considering that much lower concentrations are typically found in polluted waters and that the lower the pollutant initial concentration the better the efficiency of plasma induced oxidation. Mineralization of phenol means that also all the intermediates formed during its oxidation are mineralized. Almost complete mineralization (95%) was also found in experiments with hydrochlorothiazide, a widespread diuretic pharmaceutical prominent in the list of emerging organic contaminants, demonstrating that plasma treatment is a promising approach for obtaining complete mineralization also of organic pollutants with complex chemical composition and structure.