Electrochemical Degradation of Phenol and Resorcinol Molecules through the Dissolution of Sacrificial Anodes of Macro-Corrosion Galvanic Cells

Boguslaw Pierozynski,Grazyna Piotrowska

doi:10.3390/w10060770

Abstract

This paper reports on the processes of phenol and resorcinol electrodegradation carried-out through continuous anodic dissolution of aluminum alloy and carbon steel sacrificial anodes for artificially aerated Cu-Al alloy and Cu-Fe-based galvanic (macro-corrosion) cells and synthetically prepared wastewater solutions. Electrochemical experiments were carried-out by means of a laboratory size, PMMA (Poly-methyl methacrylate)-made electrolyser unit, where significant degrees of phenol (10–89%) and resorcinol (13–37%) decomposition were obtained and visualized through the respective chemical/spectroscopy analyses. In addition, quantitative determination of phenol, as well as resorcinol (and possible electrodegradation products) for the selected experimental conditions was performed by means of instrumental high-performance liquid chromatography/mass spectrometry analysis.

Highlights

Phenolic compounds are widely generated side-products by a number of important industries, including: petrochemical, pharmaceutical and thermoplastic processing plants
Prior to being positioned in the cell, both sacrificial anodes were first polished with emery paper down to 2000 grade; they were activated for 5 min in 5% HCl solution before being de-greased with acetone and rinsed with ultra-pure water (18.2 MΩ cm Millipore Q3 UV water purification system was used)
Operation of Cu/Al alloy and Cu/Fe galvanic cells was examined in aerated, Na2 SO4 -based electrolyte

Summary

Introduction

Phenolic compounds are widely generated side-products by a number of important industries, including: petrochemical, pharmaceutical and thermoplastic processing plants. Electrochemical oxidation processes are very attractive methods for the degradation of phenolic compounds. Some previously published works on this topic covered oxidation of numerous phenolic compounds on a number of noble/semi-noble electrode materials (i.e., Pt, Ir, Ru), as well as on transitional metals and their oxides (Ti, Sb, Sn, Pb), and various forms of carbon materials (glassy carbon, carbon fibre, graphite and boron-doped diamond electrodes), see Refs. Some other important papers published on this topic explored the removal of phenol by means of the dc-driven electrocoagulation process, carried-out through anodic dissolution of Al and Fe electrodes [13,14,15,16,17,18,19]. Employment of anodes made practically of pure aluminum [13,16,18,19] substantially increases electrical energy consumption, due to the effect of Al surface passivation

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Conclusion