Facile and scalable synthesis of long-life porous MgO-nanofiber functionalized biochar adsorbent from magnesite for phosphate recycling

The recycling of phosphate from wastewater using regenerable and highly efficient MgO-modified biochar for Mg-P fertilizer application is of great interest. However, the practical application of MgO-modified biochar for the removal and recycling of phosphate is hindered by its short-recycled service-life. Herein, a facile yet scalable method is proposed to fabricate porous MgO nanofiber-functionalized biochar (PMgNF-BC) with enhanced phosphate adsorption and regeneration performances from wastewater using waste biomass and magnesite. The as-prepared PMgNF-BC exhibited the maximum phosphate adsorption capacities of 594.53, 661.57, and 725.43 mg/g at 298.15 K, 308.15 K and 318.15 K, respectively. More importantly, PMgNF-BC demonstrated excellent regeneration performance with the removal efficiency of 84.2 % after eight regeneration cycles. Furthermore, the regenerated PMgNF-BC exhibited the well-preserved fiber shape of MgO on BC, enabling splendid regeneration performance. This work validates PMgNF-BC as a sustainable adsorbent for recycling phosphorus from wastewater, addressing the urgent need for synthesizing biochar with high regeneration performance.