Sustainable and effective catalytic particles for electrocatalytic combustion of refractory organic matter

Abstract

The development of ultra-efficient, sustainable, and easily accessible catalytic particle (CP) is a useful strategy for hydroxyl radical generation in the three-dimensional electrolytic system (3D ECs). Herein, a crystalline fused CP composed of coal gangue, activated sludge, and iron sludge, were synthesized for refractory organic matter electrocatalytic combustion in a boron-doped diamond (BDD) 3D ECs. A rough and SnO2 semiconductor metal oxide pellet-anchored continuous interface was created through a one-pot calcination method. In determination of the CP agglomeration mechanism, XRD and XPS results displayed that discrete component of SiO2, Al2O3, and Na2O were transformed into a homogeneous quartz albite NaAlSi3O8 phase, and SnO2-Sb2O5 components formed and spread in the whole ball structure during high-temperature molding process. The newly designed CP exhibited incomparable phenol degradation capacity. The dichromate oxidizability (CODCr) removal efficiency of phenolic wastewater increased 14.3 % compared to the commercial active carbon packed system. The electrocatalytic oxidation capacity of CP was evaluated comprehensively under various working condition, e. g. different cathodes, present or absent of Cl- and persulfate agents, and with or without microbubble coupling. Our experimental results showed that considerable CODCr removal efficiency of 86.3 % was obtained with microbubble coupling oxidation using cell voltage 6.0 V and treating time 120 mins. Besides these, the designed CP presented outstanding stability, and CODCr removal efficiency slightly decreased 7.1 % after 10 cycle repetitions. The use of solid waste as the main material for CPs production not only realizes harmless treatment of solid wastes but also improve the 3D ECs significantly.