Onsite greywater reuse in a low-tech solar-driven pilot laundry facility: field insights on performance, self-sufficiency, and user acceptance

Summary

This study evaluates the LaundReCycle system, a unique low-tech laundry facility designed for water and energy self-sufficiency through greywater treatment and reuse, rainwater harvesting, and solar power. Installed in Cape Town, South Africa, the system treats greywater using a settling tank, biofilter, sediment and activated carbon filters, and UV disinfection. Treated water is reused for washing, while rainwater replenishes losses and an off-grid solar setup supplies energy. The biofilter achieved 82% chemical oxygen demand (COD) and 95% turbidity removal after a 3-day retention time. This demonstrates effective treatment within a short timeframe. The results suggest potential suitability for low-grade laundry reuse. However, broader applicability may be limited by residual coloration and stable compounds. Water self-sufficiency improved during the study, reaching up to 93 %. Energy self-sufficiency reached 91.6  and 90.8 % in a scenario with increased energy efficiency and operational