Abstract In this research, a novel Microbial reverse-electrodialysis electrolysis struvite-precipitation cell (MRESC) was developed for energy recovery through struvite (MgNH4PO4·6H2O) crystallization and hydrogen production concurrently in a single process without any electrical-grid energy consumption. This hybrid system can effectively transfer the salinity gradient energy to electrical energy as a driving force to produce hydrogen gas coupled with struvite recovery and organic wastewater degradation. A MRESC containing 10 pairs of RED cells, supplied solutions typical of high concentration (600 mM NaCl) and low concentration (12 mM NaCl) at 1.0 mL/min, was operated in the fed-batch mode. The rates of hydrogen production and struvite crystallization were determined to be 0.71 m3-H2/m3-Van/d and 7.62 g/m2/h, respectively. The gas produced was > 92% H2. The Coulombic efficiency was close to or above 100% with a COD removal of 84 ± 6%, and an overall energy efficiency of 28%. The morphology and structure of the main component of accumulated crystal at the cathode were verified by a scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction. These results showed that the MRESC system could be used as an effective bioelectrochemical method for energy recovery in the form of pure hydrogen gas and struvite simultaneously.

中文翻译：

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在微生物反电渗析电解槽中同时制氢和鸟粪石回收

摘要 本研究开发了一种新型微生物反电渗析电解鸟粪石沉淀池（MRESC），通过鸟粪石（MgNH4PO4·6H2O）结晶和制氢在单一过程中同时进行能量回收，无需任何电网能源消耗。这种混合系统可以有效地将盐度梯度能量转化为电能，作为产生氢气的动力，结合鸟粪石回收和有机废水降解。包含 10 对 RED 细胞的 MRESC 以 1.0 mL/min 的速度提供典型的高浓度 (600 mM NaCl) 和低浓度 (12 mM NaCl) 溶液，在补料分批模式下运行。氢气产生速率和鸟粪石结晶速率分别测定为 0.71 m3-H2/m3-Van/d 和 7.62 g/m2/h。产生的气体> 92% H2。库仑效率接近或高于 100%，COD 去除率为 84±6%，总能效为 28%。通过具有能量色散光谱（SEM-EDS）和X射线衍射的扫描电子显微镜验证了阴极处累积晶体的主要成分的形态和结构。这些结果表明，MRESC系统可以作为一种有效的生物电化学方法，同时以纯氢气和鸟粪石的形式回收能量。通过具有能量色散光谱（SEM-EDS）和X射线衍射的扫描电子显微镜验证了阴极处累积晶体的主要成分的形态和结构。这些结果表明，MRESC系统可以作为一种有效的生物电化学方法，同时以纯氢气和鸟粪石的形式回收能量。通过具有能量色散光谱（SEM-EDS）和X射线衍射的扫描电子显微镜验证了阴极处累积晶体的主要成分的形态和结构。这些结果表明，MRESC系统可以作为一种有效的生物电化学方法，同时以纯氢气和鸟粪石的形式回收能量。