Microbial electrolytic cell combined with anaerobic digestion faces challenges such as unstable clean energy supply and inefficient cathode performance. The integration of low-cost, durable electrodes with renewable energy can enhance the microbial electrolytic cell sustainability. In this study, a metal-organic framework-modified electrode and intermittent renewable energy sources were used in the microbial electrolytic cell to treat swine wastewater. Additionally, hydrothermal carbon composite metal-organic framework were tested to reduce cathode costs and improve biocompatibility. Results showed that with 18 h of daily power from a hybrid wind-solar system, the metal-organic framework-modified cathode achieved the highest cumulative methane production of 305.11 mL/g-chemical oxygen demand and the highest net energy recovery. Increased microbial activity during the power-on period enhanced methane output and energy efficiency, making this energy supply method ideal for microbial electrolytic cells. This approach ensures efficient use of renewable energy, improving the economic feasibility of microbial electrolytic cells for wastewater treatment. The metal-organic framework-modified cathode also promoted biofilm growth, with an average thickness of 37.6 μm and enhanced microbial activity, likely due to its lower resistance and rapid current response.
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