Advanced treatment of landfill leachate using integrated coagulation/photo-Fenton process through in-situ generated nascent Al3+ and H2O2 by Cl, N co-doped aluminum-graphite composite

Herein, we report an integrated coagulation/ photo-Fenton (CPF) process for advanced treatment of mature landfill leachate using nascent aluminum ions as coagulant and hydrogen peroxide (H2O2) as oxidant for Fenton reaction, which were in-situ produced by a novel chlorine and nitrogen co-doped aluminum-graphite (Cl, N-Al -Gr) composite. The coagulation of the MBR-treated landfill leachate was performed by nascent aluminum ions generated in Cl, N-Al-Gr/O-2 system; and the resulting coagulation effluent was treated by photo-Fenton oxidation in the presence of ultraviolet (UVA). The Cl, N-Al-Gr composite exhibited excellent performance for in-situ H2O2 production (813.9 mg/L). The humic substances in landfill leachate could promote the cycle of Fe3+/Fe2+, and the removal efficiency of total organic carbon (TOC) and color was 88.1% and 97.6%, respectively under the optimized condition. The current study suggested that coagulation + Fenton process using nascent Al3+ as coagulant and in-situ generated H2O2 for Fenton oxidation could be a new way for wastewater treatment.

Automated summary

In this study, an integrated coagulation/photo-Fenton process using nascent aluminum ions and in-situ generated H2O2 was developed for the advanced treatment of landfill leachate. The process showed high removal efficiencies of TOC and color under optimized conditions, indicating its potential as a new approach for wastewater treatment.