Investigation of the oxidizing ability of bimetallic iron-aluminum and its application for the dye wastewater treatment

• Main Authors: Shu-Cheng Lin, 林書丞
• Other Authors: Hsing-Lung Lien
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/02641512522415631405

碩士 === 國立高雄大學 === 土木與環境工程學系碩士班 === 100 === This study investigated the oxidizing ability of bimetallic iron-aluminum (Fe/Al) and its application for the dye wastewater treatment. A dual functionality of Fe/Al bimetals for redox reactions has been discovered. A zero-valent Fe/Al bimetal is synthesized by depositing zero-valent iron onto the surface of zero-valent aluminum. Aluminum serves as an electron donor. The oxidative ability was investigated using methanol and formic acid as probes. Formaldehyde (transformation rate = 6.35%) was detected as an intermediate when methanol was oxidized by Fe/Al bimetals. However, completely mineralization of methanol can not be achieved by Fe/Al bimetals according to the TOC analysis. The Fe/Al bimetal can gradually and constantly release hydrogen peroxide and ferrous ion at the concentration about 25 and 50 mg/L, respectively. We demonstrate that the Fe/Al bimetals can produce oxidizing species such as the hydroxyl radical (OH‧) and the methyl radical (CH3‧) through the metal-driven Fenton reaction. Electron paramagnetic resonance (EPR) employing spin trapping techniques with 5,5-dimethylpyrroline N-oxide (DMPO) is used to confirm the generation of radicals. Textile wastewater includes a wide array of dyes and dyeing assistants causing the environmental challenge for textile industry. The Fenton reaction, a green chemical process, has been known as a homogeneous process for dye wastewater treatments. However, the overall cost and associated problems of secondary sludge generation limit its application. We present here a solid-phase hydrogen peroxide generator, zero-valent Fe/Al bimetal, for an effective mineralization of dye wastewater through the Fenton reaction. The release of hydrogen peroxide and the cycle of ferrous ion minimizes the sludge production and makes the Fe/Al bimetal a long-lasting material for dye wastewater treatments. We have tested a large variety of dye wastewater containing acid, basic, reactive and disperse dyes in reaction with Fe/Al bimetal. The COD and ADMI removal efficiency was in a range of 60-98%.