The thermally activated persulfate （PS） degradation of carbon tetrachloride （CT） in the presence of formic acid （FA） was investigated. The results indicated that CT degradation followed a zero order kinetic mode...The thermally activated persulfate （PS） degradation of carbon tetrachloride （CT） in the presence of formic acid （FA） was investigated. The results indicated that CT degradation followed a zero order kinetic model, and CO2^- was responsible for the degradation of CT confirmed by radical scavenger tests. CT degradation rate increased with increasing PS or FA dosage, and the initial CT had no effect on CT degradation rate. However, the initial solution pH had effect on the degradation of CT, and the best CT degradation occurred at initial pH 6. Cl^- had a negative effect on CT degradation, and high concentration of Cl^- displayed much strong inhibition. Ten mmol·L^-1HCO3^- promoted CT degradation, while 100mmol·L^-1NO3^- inhibited the degradation of CT, but SO4^2- promoted CT degradation in the presence of FA. The measured Cl^- concentration released into solution along with CT degradation was 75.8% of the total theoretical dechlorination yield, but no chlorinated intermediates were detected. The split of C-Cl was proposed as the possible reaction pathways in CT degradation. In conclusion, this study strongly demonstrated that the thermally activated PS system in the presence of FA is a promising technique in in situ chemical oxidation （ISCO） remediation for CT contaminated site.展开更多
基金This study was financially supported by a grant from the National Natural Science Foundation of China （Grant Nos. 41373094 and 51208199）.
文摘The thermally activated persulfate （PS） degradation of carbon tetrachloride （CT） in the presence of formic acid （FA） was investigated. The results indicated that CT degradation followed a zero order kinetic model, and CO2^- was responsible for the degradation of CT confirmed by radical scavenger tests. CT degradation rate increased with increasing PS or FA dosage, and the initial CT had no effect on CT degradation rate. However, the initial solution pH had effect on the degradation of CT, and the best CT degradation occurred at initial pH 6. Cl^- had a negative effect on CT degradation, and high concentration of Cl^- displayed much strong inhibition. Ten mmol·L^-1HCO3^- promoted CT degradation, while 100mmol·L^-1NO3^- inhibited the degradation of CT, but SO4^2- promoted CT degradation in the presence of FA. The measured Cl^- concentration released into solution along with CT degradation was 75.8% of the total theoretical dechlorination yield, but no chlorinated intermediates were detected. The split of C-Cl was proposed as the possible reaction pathways in CT degradation. In conclusion, this study strongly demonstrated that the thermally activated PS system in the presence of FA is a promising technique in in situ chemical oxidation （ISCO） remediation for CT contaminated site.
