3D electro-Fenton augmented with iron-biochar particle electrodes derived from waste iron bottle caps and sugarcane bagasse for the remediation of sodium dodecyl sulphate

Abstract

The present work demonstrates a novel strategy of synthesizing iron-biochar (Fe@BC_SB) composite made with the waste iron bottle cap and sugar cane bagasse for implementation in the three-dimensional electro-Fenton (3DEF) process. The catalytic ability of the Fe@BC_SB composite was explored to remediate the sodium dodecyl sulphate (SDS) surfactant from wastewater at neutral pH. At the optimum operating condition of Fe@BC_SB dose of 1.0 g L^-1, current density of 4.66 mA cm^-2, and Na₂SO₄ dose of 50 mM, nearly 92.7 ± 3.1% of 20 mg L^-1 of SDS abatement was attained during 120 min of electrolysis time. Moreover, the Fe@BC_SB showed significant recyclability up to six cycles. Besides, other organics were successfully treated with more than 85% abatement efficiency in the proposed Fe@BC_SB-supported 3DEF process. The total operating cost obtained during SDS treatment was around 0.31 US$ m^-3 of wastewater. The phytotoxicity test revealed the positive impact of the 3DEF-treated effluent on the germination of the Vigna radiata. The electron paramagnetic resonance conveyed ^•OH as the prevailing reactive species for the oxidation of SDS in the 3DEF process. Further, about 81.3 ± 3.8% of SDS and 53.7 ± 4.1% of mineralization efficacy were acquired from the real institutional sewage.

Keywords: Bottle caps waste; Electro-Fenton; Sugarcane bagasse; Surfactant; Waste management; Wastewater treatment.