Microbial Electrolytic Carbon Capture for Carbon Negative and Energy Positive Wastewater Treatment

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• 作者：Lu Lu ; Zhe Huang ; Greg H. Rau ; Zhiyong Jason Ren
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：July 7, 2015
• 年：2015
• 卷：49
• 期：13
• 页码：8193-8201
• 全文大小：384K
• ISSN：1520-5851

文摘

Energy and carbon neutral wastewater management is a major goal for environmental sustainability, but current progress has only reduced emission rather than using wastewater for active CO₂ capture and utilization. We present here a new microbial electrolytic carbon capture (MECC) approach to potentially transform wastewater treatment to a carbon negative and energy positive process. Wastewater was used as an electrolyte for microbially assisted electrolytic production of H₂ and OH^{鈥?/sup> at the cathode and protons at the anode. The acidity dissolved silicate and liberated metal ions that balanced OH鈥?/sup>, producing metal hydroxide, which transformed CO₂ in situ into (bi)carbonate. Results using both artificial and industrial wastewater show 80鈥?3% of the CO₂ was recovered from both CO₂ derived from organic oxidation and additional CO₂ injected into the headspace, making the process carbon-negative. High rates and yields of H₂ were produced with 91鈥?5% recovery efficiency, resulting in a net energy gain of 57鈥?2 kJ/mol-CO₂ captured. The pH remained stable without buffer addition and no toxic chlorine-containing compounds were detected. The produced (bi)carbonate alkalinity is valuable for wastewater treatment and long-term carbon storage in the ocean. Preliminary evaluation shows promising economic and environmental benefits for different industries.}