| Summary: | 碩士 === 雲林科技大學 === 環境與安全工程系碩士班 === 97 === In this research, recovery cuprous oxide was made by microwave hydrothermal methods from the waste liquid including heavy metal which was acidic leached from heavy metal sludge of printed circuit board. In yield of recovery cuprous oxide, using microwave hydrothermal at low-power of 200 W and short reaction time of 15 min was the highest in all conditions of this research and reached energy-saving. In XRD, the results showed the recovery cuprous oxide peak in 2θ=36.65o and 42.50o and in SEM, cuprous oxide crystal was round and homogeneous. Therefore, the recovery cuprous oxide was applied in Fenton-like (H2O2/Cu2O) and Photo-Fenton-like (UV/H2O2/Cu2O) systems to degrade aqueous dye (RB 19). Compared with the ultra-violet light (365 nm) and visible light (410 nm), the dye degradation was more than 90% under 410nm irradiation, H2O2 added more than 5 mM and reacting after 90 min. The result indicated that Photo-Fenton-like (UV/H2O2/Cu2O) system maintained photoactivity under visible light irradiation. However, in copper ions released analysis, the copper ions released more than 3 mg/L and exceeded waste water standards in Taiwan when under 365 nm irradiation, more than 5 mM of H2O2 but did not exceed 3 mg/L when under 410 nm irradiation. The results pointed out that the optimum degradation condition was visible light. In analysis operating costs, microwave hydrothermal to prepare recovery cuprous oxide cost 388 NT dollars/kg-Cu2O and was lower than commercial cuprous oxide and Photo-Fenton-like (UV/H2O2/Cu2O) system to treat dye wastewater in this research cost 1336 NT dollars/ton-wastewater. This results established that natural light might be useful in Photo-Fenton-like (UV/H2O2/Cu2O) system, because of effective degradation and more energy savings.
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