Towards the circular economy — Sustainable fouling mitigation strategies in ultrafiltration of secondary effluent

Membrane separation is an emerging technology for secondary effluent (SE) recycling as alternative water source. However, SE contains metabolites which form a film on membrane surfaces, leading to decrease in hydraulic capacity. This extensive study of the effect fouling UF performance, with detailed analysis foulants composition and morphology, evaluation most effective – either physical or chemical regeneration methods. The paper also investigates FNA (recycled from WWTPs) acidic cleaning agent. In UF-DE mode, backwashing configuration was 1 s every min, where relative permeability decreased by 54% after 4-h, indicated presence physically irreversible separation. An acidic-alkaline procedure contribution 13% resulted 100% efficiency regeneration. results confirmed that recycled efficient pure reagent-nitric acid V use can reduce costs 60%. To fit idea circular economy, we proposed new strategy reusing spent solutions fertiliser.