Construction of novel electrochemical treatment systems for indigo wastewater and their performance

Abstract

Purpose

This study aims to evaluate the efficiency of metal electrode and electrolytes on the electroflocculation of indigo wastewater, produced by printing and dyeing factory, and to optimize the treatment system.

Design/methodology/approach

For effective purging, various types of metal electrodes (graphite, pure aluminum and stainless steel) and supporting electrolytes (sodium chloride and sodium sulfate) were selected for electroflocculation experiments. The decolorization rate and chemical oxygen demand (COD) removal rate were characterized.

Findings

The treatment effects of stainless steel and aluminum were similar, but the dissolution loss of aluminum and the production of flocs greatly limit its application. Electrolytes gave obvious effects to these systems. Sodium sulfate was better than sodium chloride, the decolorization rate was increased by 3.31%, the removal rate of COD in the solution was increased by 28.65% and the weight of flocculation precipitation was reduced by 0.214 g.

Research limitations/implications

The electrochemical treatment system was constructed to compare and analyze the influence of experimental parameters and to provide a reference for the actual treatment of indigo wastewater.

Practical implications

Electrochemical flocculation can remove the insoluble indigo solids and it plays a key role in wastewater treatment.

Originality/value

It is novel to optimize the combination of electrode and electrolyte to improve the efficiency of electroflocculation, which can be widely used in the actual wastewater treatment process.

Citation

Huangfu, Z., Zhang, W., Hao, S., Zhang, M. and Yao, J. (2021), "Construction of novel electrochemical treatment systems for indigo wastewater and their performance", Pigment & Resin Technology, Vol. 50 No. 3, pp. 264-270. https://doi.org/10.1108/PRT-07-2020-0068