Highly active Fenton-like catalyst derived from solid waste-iron ore tailings using wheat straw pyrolysis

Abstract

The pollutants degradation rate of iron ore tailings-based heterogeneous catalysts is the main factor limiting its application. Herein, an iron ore tailings-based Fenton-like catalyst(I/W(3:1)-900-60) with relative fast catalysis rate was constructed by co-pyrolysis(900 ℃, 60min holding time) of iron ore tailings and wheat straw with mass ratio of 3:1. With wheat straw blending, the generated I/W(3:1)-900-60 presented a larger surface area(24.3 m 2 /g), smaller pore size(3.707 nm), reduced iron species (Fe 2+ from magnetic) and a higher catalytic activity(0.0229 min -1 ) than I-900-60 (1.196 m 2 /g, 12.935 nm, 0.012 min -1 ) pyrolyzed using a single iron ore tailings under the same pyrolysis conditions. In addition, biochar and iron ore tailings in I/W(3:1)-900-60 were tightly combined through chemical bonding. The optimal catalyst remains active after three cycles, indicating its catalytic stability and recyclability. The good Fenton-like MB degradation efficiency of I/W(3:1)-900-60 was ascribed to the sacrificial role of biochar, as well as the electron transfer between biochar and iron active sites or the 2 redox cycles of ≡Fe 3+ /Fe 2+ . This finding provides a facile construction strategy for a highly active iron ore tailings-based Fenton-like catalyst, and thereby had a great potential application in wastewater treatment.