A novel functional biodegradable electrospun membrane for nutrient recovery

The growing shortage of essential nutrients, such as nitrogen and phosphorous, is prompting researchers to find advanced recovery processes from wastewater derived from sewage treatment plants and other wastewater sources. In this work we propose a novel compostable electrospun filtration membrane based on poly(L-lactic acid) (PLLA), for nutrient recovery through struvite crystallization from water. Composite electrospun PLLA fibers were fabricated starting from a suspension of PLLA solution and struvite crystals. Struvite within PLLA fibers worked as a nucleant agent for additional crystallization of magnesium, ammonium and phosphate hexahydrate out of water. Morphological, structural and physical properties of the obtained membranes were studied and the ammonium concentration decrease in the analyzed water samples was measured and correlated to struvite precipitation on the electrospun membranes. The obtained compostable struvite-rich membrane can be used in agriculture to provide a nutrient-rich humus for direct application to the land.