[A-GE40] [EE] Energy-Environment-Water Nexus and Sustainable Development

[AGE40-P21] Reductive Dechlorination of Carbon Tetrachloride by Microscale Sponge Iron

*Xueqiang ZHU¹, Baoping Han², Qiyan Feng¹ (1.China University of Mining and Technology, 2.Jiangsu Normal University)

Keywords:Carbon tetrachloride, Sponge iron, Reductive dechlorination

Chlorinated hydrocarbons are the most prevalent groundwater pollutants that pose a risk to public health. The degradation of CCl₄ by sponge iron and factors affecting degradation efficiency including acid washing, dosage and initial pH were investigated through batch experiments in this study. Results showed that CCl₄ was effectively degraded by sponge iron and about 75 percent of CCl₄ was transformed into chloroform (CF) by hydrogenolysis process. The rate of CF transformation was slower than that of CCl₄, resulting in the CF accumulation. Surface acid activation showed slight influence on CCl₄ degradation with ZVI. The CCl₄ degradation reactions followed pseudo-first-order kinetics, and the apparent first-order rate constant (k_obs) increased linearly with increasing ZVI dosage and the suitable dosage of 20g/L was indicated in terms of surface area-normalized rate constants (k_SA). The k_obs decreased with the increasing of pH value and the process indicated that the degradation of CCl₄ had a better performance under weak acidic condition.