Anaerobic membrane bioreactor for hygiene wastewater treatment in controlled ecological life support systems: Degradation of surfactants and microbial community succession

The treatment and reuse of hygiene wastewater is crucial to "close the loop" in the controlled ecological life support system (CELSS), and to guarantee longer space missions or planetary habitation. In this work, anaerobic membrane bioreactor (AnMBR) was applied for hygiene wastewater treatment, focused on surfactant degradation and microbial community succession. The removal efficiency of COD and surfactants was 90%similar to 97% and 80% with a urine source-separation strategy. The microbial community gradually shifted from methanogens to sulfur-metabolizing and surfactant-degradation bacteria, such as Aeromonas. Sulfate was a surfactant degradation product, which triggered sulfate reduction and methane inhibition. The activated carbohydrate and sulfur metabolism were the key mechanism of the microbial process for the excellent performance of AnMBR. This study analyzed the degradation mechanism from the perspective of microbial mechanism, offers a solution for CELSS hygiene wastewater treatment, and supports the future improvement and refinement of AnMBR technology.