Fabrication, characterizations and performance of a high-efficiency micro-electrolysis filler for isobutyl xanthate (IBX) degradation

Highlights: • The preparation process of filler was optimized based on properties and performance. • The Fe substance in filler can be transferred to fayalite (Fe₂SiO₄) with very thin O₂. • The filler which contain Fe₂SiO₄ has enhanced performance for IBX degradation. Micro-electrolysis is a cost-effective method widely applied in wastewater treatment. In this paper, a high-efficiency micro-electrolysis filler was prepared by a facile calcination method for the degradation of isobutyl xanthate (IBX). The optimization of filler fabrication process was investigated from aspects of compressive strength, abrasion loss and degradation rate. Combined with multi-characterization techniques, it can be found that the zero-valent iron (ZVI) was partially changed to Fe(2+) in the phase of fayalite (Fe₂SiO₄) during the treatment. The influence of operation parameters of filler dosage, initial pH and initial concentration were thoroughly studied. The result shows that the IBX degradation rate by optimized filler can reach 93.30%, superior to that of Fe/C filler (the element Fe kept at ZVI during heat treatment) with 61.8% removal. The degradation pathway of IBX was studied by GC-MS in details and the bis(2-methylpropyl)carbonate was postulated as the main by-product. The stability of filler was evaluated by batch cycle tests and column tests. This work provides a novel perspective about micro-electrolysis filler preparation. The extraordinary performance brings it potential for industrial application.