Chlorophenolic contaminants represented by 2,4-dichlorophenol (2,4-DCP) are ubiquitous persistent and toxic organic pollutants in aqueous environments, posing severe threats to ecological safety and human health. Bimetallic zero-valent iron systems have emerged as promising candidates for the remediation of chlorinated wastewater; nevertheless, their practical application is greatly hindered by inevitable nanoparticle aggregation, poor dispersion, and insufficient exposure of active sites. To overcome these limitations, tannic acid (TA) with abundant phenolic hydroxyl groups was rationally grafted onto three-dimensional porous polyurethane foam (PU) to construct a novel composite support. Benefiting from the strong metal chelation of TA, Fe/Pd bimetallic nanoparticles were uniformly dispersed and firmly immobilized on the TA-PU skeleton, successfully fabricating the stable TA-PU-Fe/Pd catalytic composite. The catalytic performance toward 2,4-DCP degradation was systematically evaluated. Compared with conventional carriers such as activated carbon, zeolite and Al 2 O 3 , the as-prepared TA-PU-Fe/Pd exhibited remarkably enhanced removal activity, achieving a 2,4-DCP removal efficiency of 99.7% at an initial concentration of 20 mg/L. Moreover, the composite possessed outstanding cyclic reusability, retaining a high removal rate of 98.7% even after ten reaction cycles. Satisfactory treatment performance was also realized at a low pollutant level of 2 mg/L, with the removal efficiency reaching 93.0%, demonstrating great application potential for the remediation of actual chlorophenol-contaminated water.
Guo et al. (Mon,) studied this question.