Production of high-quality water from a condensate stream extracted from lunar regolith

In the context of extending human presence into deep space, particularly on the Moon, in-situ resource utilization (ISRU) is essential for sustaining long-term missions. This study investigates water purification system designed to treat synthetic water containing methanol, simulating volatile impurities typically found in regolith-derived condensate streams. The system combines direct contact membrane distillation (DCMD), UV photolysis and hydrolysis. Experiments were conducted using methanol concentrations of 30 mg/L and 100 mg/L at varying temperatures. direct contact membrane distillation (DCMD) demonstrated efficient methanol transport, achieving a recovery rate of up to 40.2% at 50°C for 30 mg/L concentration. However, higher temperatures accelerated feed depletion and reduced selectivity because of the increased water vapor flux. Standalone UV photolysis partially degraded methanol, and future enhancements could be achieved by integrating catalysts (e.g., TiO₂) or oxidants (e.g., H₂O₂). Hydrolysis showed negligible degradation, likely due to the absence of catalytic activation and the ambient temperature and pressure conditions under which the tests were conducted. The findings highlight the potential of a compact, energy-efficient purification system suitable for lunar applications, while also offering insights into terrestrial industries managing methanol-contaminated wastewater through more sustainable, low-energy treatment strategies.