Pretreatment of blackwater improves the use of membranes for water treatment

Membrane distillation is a potential technology for non-sewered sanitation to achieve a high standard of treated wastewater. However, there have previously been issues with membrane distillation’s potential when it comes to concentrated blackwater. 

Treating concentrated blackwater with ultrafiltration before using membrane distillation has been shown to improve many factors of membrane distillation as a wastewater treatment method. Ultrafiltration removed large particulates from the blackwater, meaning that the membrane distillation permeability was raised to similar levels to that of just urine. This increase makes the membrane distillation water quality to acceptable standards for discharge or reuse.  

These findings show that membrane distillation can provide a robust means for concentrated blackwater treatment. As the energy required for ultrafiltration is primarily heat, this treatment can be delivered to areas with more fragile power networks, making it more accessible to the communities in need of safe, non-sewered sanitation options. 

Full article: Ultrafiltration pretreatment enhances membrane distillation flux, resilience and permeate quality during water recovery from concentrated blackwater (urine/faeces), Farhad Kamranvand et al, Separation and Purification Technology