| Summary: | 碩士 === 淡江大學 === 水資源及環境工程學系碩士班 === 98 === Advanced oxidation processes (AOPs) were wildly studied for dye wastewater treatment. Among the AOPs,Fenton process was the most discussed treatment technologies. However, Fenton process has following disadvantages including high dosage required and large amount of sludge generated. Therefore, the objective of this study is to study ultrasound-activation of persulfate to produce a very powerful oxidant, sulfate free radical, for dye wastewater treatment. Sodium persulfate is a stable and harmless material for environment. The results showed ultrasound can activate persulfate, and the reaction temperature can reach up to70℃. Comparison of ultrasound- and heat-activation of persulfate for dye removal , ultrasound-activation shows higher removal efficiency of dye than heat-activation when temperature is fixed at 25 and40 ℃. However, ultrasound-activation has lower color removal efficiency than heat-activation when temperature is fixed at 60℃.
Zero-valent iron (ZVI) was also used for persulfate activation under batch and column reactors. The experimental results showed color removal efficiency increased with the increase of persulfate concentration, but decreased with the increase of initial pH value. In the experiment of zero-valent iron combined hydrogen peroxide, color removal efficiency decreased with the decreased of hydrogen peroxide concentration, but decreased with the increase of initial pH value due to passivation of ZVI by iron oxide. For both ZVI/persulfate and ZVI/hydrogen peroxide systems, optimized pH value for dye removal was found to be 3.0. In ZVI column experiments, the results showed the initial pH value and HRT did not significantly impact the degradation of dyes.
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