Black liquor is a complex waste stream generated from the fast-expanding biorefinery industry, and the high management cost has been known as a major development barrier. In this work, we demonstrated a rationally designed 4-chamber microbial electrolysis process that was capable of recovering the value-added lignin, NaOH, and H₂ products while removing waste organics from the Deacetylation and Mechanical Refining (DMR) black liquor, which could potentially reduce the disposal cost by up to 40%. The lab-scale MEC achieved 52% organic removal from a highly concentrated feedstock (28,960 ± 212 mg/L COD) and recovered 83.2 mM NaOH under a small voltage application (1.2 V). Lignin recovery was observed to be as high as 13.98 ± 0.28 g/L, and 0.35 L/L/day H₂ was produced with a faradaic efficiency of 93.5%. This work provided a good example on how complex liquid waste stream can be valorized via multi-functional microbial electrochemical technology, and how the traditionally unfavored pH gradient in an electrochemical reactor can be manipulated for lignin precipitation and alkaline recovery at the same time. The versatility and good performance in concurrent contaminants removal, lignin precipitation, H₂ production and NaOH recovery demonstrate a good potential for microbial electrolysis in black liquor treatment.

黑液是快速发展的生物炼制行业产生的一种复杂的废物流，高昂的管理成本被称为主要的发展障碍。在这项工作中，我们展示了一种设计合理的 4 室微生物电解工艺，该工艺能够回收增值的木质素、NaOH 和 H ₂产品，同时从脱乙酰和机械精炼 (DMR) 黑液中去除废有机物，可以可将处置成本降低多达 40%。实验室规模的MEC 从高浓度原料 (28,960 ± 212 mg/L COD) 中去除了 52% 的有机物，并在小电压应用 (1.2 V) 下回收了 83.2 mM NaOH。观察到木质素回收率高达 13.98 ± 0.28 g/L 和 0.35 L/L/天 H ₂法拉第效率为 93.5%。这项工作提供了一个很好的例子，说明了如何通过多功能微生物电化学技术对复杂的废液流进行增值，以及如何控制电化学反应器中传统上不利的 pH 梯度以同时进行木质素沉淀和碱回收。在同时去除污染物、木质素沉淀、H _{2生产和 NaOH 回收方面}的多功能性和良好性能证明了黑液处理中微生物电解的良好潜力。