A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management

Thesis (M.Eng.) - Asian Institute of Technology, 2009

PFOA and PFOS, predominant of perfluorinated compounds, are being considered as candidates of new POPs. The effectiveness of nZVI and ZnO nanoparticles in PFOA/PFOS removal was determined in this study with respect to nanoparticles dosage, reaction time and catalytic effects such as ZnO nanoparticles with sunlight. The PFOAIPFOS synthetic wastewaters were employed in the concentration of 1 mg/L. The experimental results suggested the effectiveness of using nZVI and ZnO nanoparticles to remove PFOA/PFOS present in wastewaters. The optimum dosages of nZVI which resulted in the highest PFOA/PFOS removal efficiencies of 72.12 ± 6.88% and 89.20 ± 0.55%, respectively at the reaction time of 1 hr were 500-1000 mg/L. The PFOAIPFOS removal efficiencies by the ZnO nanoparticles dosage of 100 mg/L with exposure to sunlight for 1 hr were found to be 14.14 ± 1.27% and 16.32 ± 5.84%, respectively. Moreover, the reaction time of nZVI to remove PFOA/PFOS was rapid, within 1- min. For ZnO nanoparticles, the PFOA/PFOS removal efficiencies were found to increase with longer reaction times. The intermediate products and the final reduction reaction products of PFOAIPFOS degradations could not be detected during these experiments. Relationships between PFOA/PFOS removal efficiencies and nZVI/ZnO nanoparticles dosages were developed. Mass balance analysis of PFOAIPFOS removal by nZVI found that most of the removal was due to degradation, while adsorption percentages were only less than 5%. Based on the values of the removal coefficients and mass balance analysis, it could be suggested that PFOA was more resistant to be removed by both nZVI and ZnO nanoparticles than PFOS. The nZVI could be used to remove PFOA/PFOS better than ZnO nanoparticles at the same nanoparticles dosage