Taguchi orthogonal optimization for the oxidative degradation of 2-chlorophenol using zero valent iron-activated persulfate

TL;DR

This study uses zero-valent iron and persulfate to efficiently degrade 2-chlorophenol in groundwater, achieving full degradation in 10 minutes.

Contribution

The novel application of Taguchi optimization identifies optimal conditions for 2-chlorophenol degradation using zero-valent iron-activated persulfate.

Findings

SPS concentration was the most significant factor affecting 2-CP degradation.

100% degradation of 2-CP was achieved in 10 minutes under optimal conditions.

Groundwater constituents affected degradation efficiency, with 75% and 67% total organic carbon removal in reverse osmosis and groundwater samples.

Abstract

Chlorophenols (CPs) are persistent toxicants and major groundwater pollutants due to their carcinogenic properties. This study focused on optimizing the degradation of 2-chlorophenol (2-CP) in the aqueous phase using zero-valent iron (ZVI)-activated sodium persulfate (SPS). The Taguchi Design of Experiment methodology (L9 orthogonal array) and ANOVA statistical analysis were applied to identify optimal conditions, with key parameters including initial pH, SPS concentration, and ZVI concentration. Results indicated that SPS concentration had the most significant impact on 2-CP degradation. Confirmation tests conducted at the optimal conditions (pH = 6, SPS = 60 mM, ZVI = 60 mM) achieved 100% 2-CP degradation within 10 min, characterized by rapid 2-CP degradation, SPS decomposition, and 2-CP mineralization. Experiments with 2-CP spiked reverse osmosis water and groundwater samples showed total organic carbon removal rates of 75% and 67%, respectively, with discussions highlighting the potential effects of groundwater constituents on degradation efficiency. ZVI surface analysis through SEM-EDS identified iron oxide crystal formation on recovered iron particles, while XRD analysis confirmed the presence of Fe3O4 on the particle surface post-reaction. These findings underscore the effectiveness of ZVI-activated SPS as a promising approach for 2-CP degradation in natural groundwater systems, contributing to supportable groundwater remediation efforts.

Zero-valent iron-activated persulfate: a promising approach for 2-chlorophenol degradation in groundwater.

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