| Summary: | 碩士 === 國立雲林科技大學 === 環境與安全衛生工程系 === 107 === Copper is a raw material commonly used in industrial manufacturing processes. Methods to treat copper-containing wastewater can be physical, chemical, or biological. Physical and chemical approaches are common treatment technologies; however, both methods have disadvantages of high cost and secondary pollution. The conventional biological approach has the limitation of slow microbial growth. This study cultured white rot fungi (WRF) at the cathode of a single-chamber ceramic microbial fuel cell (WRF-C-MFC) to treat copper-containing wastewater. The adsorption and water absorbing characteristics of ceramic allow it to be used as a proton exchange membrane to reduce the concentration of heavy metals and mitigate the inhibition against microbes. The laccase generated by WRF was used as the catalyst of MFC at the cathode to accelerate the redox reaction of the MFC to thereby increase the power generation capacity, power output, and copper ion recovery efficiency. The results revealed that (1) Pleurotus eryngii was the fungus featuring the highest tolerance to copper ions. When solutions with 15 mg/L copper ion concentration was added to solid-state cultivation of Pleurotus eryngii, the laccase activity reached 277.8 U/L, which was three-fold higher than that of other fungus species. (2) The C-MFC was able to effectively treat copper ions in wastewater. The closed-circuit voltage output reached 153±23 mV. The removal of chemical oxygen demand under the closed-circuit condition was approximately 1.8-fold higher that than under the open-circuit condition. Cultivation of WRF further improved the power generation capacity and power output efficiency. (3) When the copper ion inlet was 50 mg/L, the WRF-C-MFC reached a 100% copper ion removal efficiency within 24 hours and the maximum closed-circuit voltage output reached up to 415 mV. When the copper ion concentration increased to 250 mg/L, the removal efficiency decreased gradually. Under this circumstance, microbes were inhibited by high concentration of copper ions and caused a considerable decline in power generation capacity. When copper ion-free solution was used to replace the original solution, the voltage nearly resumed to initial values. (4) WRF can effectively adsorb and recover copper ions in ceramics using the WRF-C-MFC. The laccase activity reached 392 U/L, approximately 2.5 folds higher than when in solution free of copper ions. (5) Copper ions in wastewater could be effectively recovered by the WRF-C-MFC at the cathode to form Cu(OH)2.
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