2026-04-27T12:32:12Zhttps://uvadoc.uva.es/oai/request

oai:uvadoc.uva.es:10324/742802025-02-06T09:43:10Zcom_10324_1137com_10324_931com_10324_894col_10324_1222

Oliveira, Veronica Dias Ferreira, Celia González García, Isabel Labrincha, João Horta, Carmo García González, María Cruz The recovery of valuable materials from waste fits the principle of circular economy and sustainable use of resources, but contaminants in the waste are still a major obstacle. This works proposes a novel approach to recover high-purity phosphorus (P) and nitrogen (N) from digestate of municipal solid waste based on the combination of two independent membrane processes: electrodialytic (ED) process to extract P, and gas permeable membranes (GPM) for N extraction. A laboratory ED cell was adapted to accommodate a GPM. The length of waste compartment (10 cm; 15 cm), current intensity (50 mA; 75 mA) and operation time (9 days; 12 days) were the variables tested. 81% of P in the waste was successfully extracted to the anolyte when an electric current of 75 mA was applied for 9 days, and 74% of NH4+ was extracted into an acid-trapping solution. The two purified nutrient solutions were subsequently used in the synthesis of a biofertilizer (secondary struvite) through precipitation, achieving an efficiency of 99.5%. The properties of the secondary struvite synthesized using N and P recovered from the waste were similar to secondary struvite formed using synthetic chemicals but the costs were higher due to the need to neutralize the acid-trapping solution, highlighting the need to further tune the process and make it economically more competitive. The high recycling rates of P and N achieved are encouraging and widen the possibility of replacing synthetic fertilizers, manufactured from finite sources, by secondary biofertilizers produced using nutrients extracted from wastes. 2025-01-22 2025-01-22 2021 info:eu-repo/semantics/article Waste Management, abril 2021, vol. 125, p. 293-302 0956-053X https://uvadoc.uva.es/handle/10324/74280 10.1016/j.wasman.2021.02.055 293 302 Waste Management 125 spa info:eu-repo/semantics/openAccess