Textile dye degradation using nano zero valent iron: A review

Area of Science:

• Environmental Chemistry
• Materials Science
• Nanotechnology

Background:

• Textile dyeing wastewater contains persistent pollutants like dyes and salts.
• Current treatment methods are insufficient for complete dye degradation, posing environmental risks.
• Nano zero valent iron (nZVI) is emerging as a potent technology for textile dye remediation.

Purpose of the Study:

• To review the current knowledge on using nano zero valent iron (nZVI) for textile dye degradation.
• To assess the advantages, challenges, and future directions of nZVI application in textile wastewater treatment.

Main Methods:

• Review of existing literature on nZVI for textile dye degradation.
• Analysis of nZVI particle stability, supported nZVI systems, and degradation mechanisms.
• Evaluation of studies focusing on dye color removal versus complete compound degradation (TOC removal, byproduct identification).

Main Results:

• nZVI is highly reactive, economical, and less toxic for dye degradation.
• nZVI particle aggregation necessitates the use of supports (e.g., biochar, graphene) to enhance stability.
• Green supports are advised to prevent the introduction of additional pollutants.
• Many studies focus on color removal, not complete mineralization; partial mineralization is often achieved.
• Integration of nZVI with other techniques is suggested for complete degradation and multi-pollutant treatment.

Conclusions:

• nZVI is a promising technology for textile dye wastewater treatment, but stability and complete degradation remain challenges.
• Further research, including bench-scale and pilot-scale studies, is crucial for practical application.
• Focus should shift from color removal to assessing complete organic compound degradation and byproducts.