The dyeing process is a very important unit operation in the leather and textile industries; it produces significant amounts of waste effluent containing dyes and poses a substantial threat to the environment. Therefore, degradation of the industrial dye-waste liquid is necessary before its release into the environment. The current is focusing on the reduction of pollutant loads in industrial wastewater through remediating azo and thiazine dyes (synthetic solutions of textile dye consortium). The current research work is focused on the degradation of dye consortium through photo-electro-Fenton (PEF) processes via using dimensionally stable anode (Ti) and graphite cathode. The ideal conditions, which included a pH of 3, 0.1 (g/L) of textile dye consortium, 0.03 (g/L) of iron, 0.2 (g/L) of H2O2, and a 0.3 mAcm-2 of current density, were achieved to the removal of dye consortium over 40 min. The highest dye removal rate was discovered to be 96%. The transition of azo linkages into N2 or NH3 was confirmed by Fourier transforms infra-red spectroscopic analysis. PEF process reduced the 92% of chemical oxygen demand (COD) of textile dye consortium solution, and it meets the kinetics study of the pseudo-first-order. The degradation of dye through the PEF process was evaluated by using the cyclic voltammetric method. The toxicity tests showed that with the treated dye solution, seedlings grew well.

Treatment of textile dye consortium through photo-electro-fenton process using graphite-Ti electrode system and toxicity studies
    Abstract 
    Graphical abstract
    1 Introduction
    2 Materials and methods
        2.1 Preparation of PEF process reactor
        2.2 Textile dye consortium degradation by PEF process
        2.3 Instrumental analysis of the synthetic textile dye consortium solution before and after the PEF process
        2.4 Chemical oxygen demand (COD) analysis
        2.5 Toxicity assessment
        2.6 Kinetic study
    3 Results and discussion
        3.1 Preparation and characterization of synthetic textile dye consortium
        3.2 Effect of pH on decolorization of synthetic textile dye consortium solution
        3.3 Impact of dye concentration on the PEF process
        3.4 Impact of iron catalyst on dye decolorization
        3.5 Impact of H2O2 on dye decolorization
        3.6 Impact of current density on dye decolorization
        3.7 Instrumental analysis for dye degradation using the PEF process
        3.8 Chemical oxygen demand (COD) analysis
        3.9 Toxicity assessment of treated synthetic textile dye consortium solution
        3.10 Kinetic studies
    4 Conclusions
    References

• E. Gomathi(Department of Petrochemical Technology, University College of Engineering—BIT Campus, Anna University, Tiruchirappalli, Tamilnadu 620024, India)
• P. Maharaja(Environmental Engineering Department, CSIR-Central Leather Research Institute (CLRI), Adyar, Chennai, Tamilnadu 600020, India)
• R. Boopathy(Department of Environment and Sustainability (IMMT), CSIR-Institute of Minerals and Materials Technology, Bhubaneshwar, India)
• Rames C. Panda(Chemical Engineering Division, CSIR—Central Leather Research Institute (CLRI), Adyar, Chennai 600 020, India)
• T. Senthilvelan(Department of Molecular Analytics, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Tamilnadu 602105 Chennai, India)
• Maruthapillai Arthanareeswari(Department of Chemistry, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Tamilnadu 603203 Kattankulathur, India)
• Hanumant Singh Rathore(Department of Biotechnology, School of Engineering & Technology, Nagaland Central University, Dimapur, Nagaland 797112, India)