A study on degradation of trichlorethylene by zero-valent aluminum coated with polymethylmethacrylate

• Main Authors: Hsieh, Cheng-An, 謝承安
• Other Authors: Huang, Yi-Chu
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/jwnsp5

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 105 === For the remediation technology using zero-valent metals, zero-valent iron (ZVI) is the most frequently adopted. However, ZVI is not easy to synthesize and has the risk of secondary pollution. In recent years, other zero-valent metals such as zero-valent aluminum (ZVAl) have been taken seriously. The redox potential (ORP) of ZVAl is higher than that of ZVI, therefore the pollutant degradation performance with ZVAl is theoretically stronger that with ZVI resulting in easily forming passivation layer and lowing the degradation capability to pollutants. To overcome the liable oxidation problem of ZVAl, that is coated by polymethylmethacrylate (PMMA) to prevent it from oxidation. In this study, the microemulsion method was applied to readily synthesize the polymethylmethacrylate zero-valent aluminum particles (PZVAl). This technology of coating polymers not only prevents ZVAl particles from being oxidized in the air, but also increases the removal result of ZVAl on trichlorethylene (TCE), and polymethylmethacrylate will not harm the environment. This study found that the effect of PZVAl removal of TCE was 5.2% higher than that of ZVAl within 4 hours, however, a further analysis showed that the chloride ion production of PZVAl did not increase relative, it is possible that PMMA increases the chance of aluminum hydroxide contacting contaminants, increasing the amount of aluminum hydroxide adsorbed. As the addition of PZVAl ranging from 1 to 6 g, the best removal performance of PZVAl to PCE is 5 g under the same conditions, 85.7% of TCE were removed in 4 hours. For the reaction temperature, 60 ℃ showed the best results and 89.7% of TCE were removed in 4 hours. Chloride concentration increased with higher reaction temperature. It showed that TCE removal rate raised with higher reaction temperature, too. Adjustment of pH value did not significantly affect the removal of TCE. This may be due to wider suitable pH range for TCE removal by ZVAl. The results of this study can be provided as a design reference for removal of chlorinated solvents using zero-valent metals.