Photothermal activation of peroxydisulfate using iron nanoparticles/MXene@polyurethane sponge module for treatment of landfill leachate: From lab to pilot scale

Treatment of landfill leachate and recovery of recycled water in photothermal activation of peroxydisulfate (PDS) process using iron nanoparticles/MXene-coated polyurethane sponge module (Fe NPs/MXene@PU) were investigated from lab to pilot scale for the first time. In the module preparation process, nanoscale zero-valent iron (NZVI) and iron oxides were in situ generated on Ti 3 C 2 MXene surface. Fe NPs/MXene@PU module reached the 147.7 °C interfacial temperature due to the synergistic effect of MXene and in-situ generated Fe NPs. Sulfate radical (SO 4 •- ) and hydroxyl radical (HO • ) were generated in photothermal activation of PDS process. Under optimized reaction conditions, almost complete removal of chemical oxygen demand (COD), nitrate nitrogen (NO 3 – ), ammonia nitrogen (NH 3 -N) and total phosphorus (TP) of landfill leachate was achieved after about 40 d pilot-scale experiment in the open air. The recycled water collected by natural condensation was also purified, which contained ultralow concentrations of COD, NH 3 -N, NO 3 – , TP and heavy metals and met the discharge limits of various countries. This study provides an eco-friendly and energy-efficient technology for treatment of landfill leachate and recovery of recycled water.