Nitrobenzene reduction using nanoscale zero-valent iron supported by polystyrene microspheres with different surface functional groups

Abstract

Three polystyrene (PS) resin microspheres supported nanoscale zero-valent iron (nZVI), i.e., nZVI@PS, nZVI@PS-Cl, and nZVI@PS-N, were prepared and characterized by FT-IR, XPS, SEM, EDS, and weighing method. The functional groups on the carriers showed obvious influence on the loading quantity, the micro morphology, and the reduction efficiency of these supported nZVI. The best hybrid reducer was nZVI@PS-N. The load quantity of nZVI was 0.2476 g/g, and some of them were dispersed and the others remained as particles (≤ 50 nm). At optimal reaction conditions, i.e., initial solution pH = 3, 25 °C, 100 r/min stirring, 99% nitrobenzene (NB) in 250 mL 123.1 mg/L NB solution could be totally reduced into AN by 1.31 g fresh nZVI@PS-N within 20 min. The excellent reduction efficiency and fast degradation rate of nZVI@PS-N were mainly attributed to the synergistic effects between the good adsorption property of its carrier and the high reduction activity of nZVI particles. NZVI@PS-N was reproducible and recycled, and 90.6% degradation ratio of NB was till obtained at its seventh recycle. The results showed that nZVI@PS-N had high potential practical application value in the reductive degradation and emergency rescue of nitrobenzene pollutant.

Enhanced Mechanism of Nano Zero-Valent Iron Activated Persulfate for Persistent Organic Pollutants in the Environment

“…Studies have shown that nZVI can efficiently activate persulfate. Li et al [57]activated PS by nZVI to remove nitrobenzene, the results found that higher temperature and acidic conditions are more conducive to the removal of nitrobenzene, and the removal rate can reach 99%. Wu et al [58] used nanoscale zero-valent iron supported on the organo-montmorillonite composite to activate PS, and the degradation rate of sulfamethazine can reach 97% within ten minutes.…”

Preparation of a Novel Cellulose–Styrene Copolymer Adsorbent and Its Adsorption of Nitrobenzene from Aqueous Solutions

“…Polystyrene is a major material type in microplastics, and it has a stronger sorption capacity for aromatic compounds due to π–π interactions [ 30 , 31 ]. The surface of polystyrene is hydrophobic and contains a relatively large number of active aromatic sites that allow π–π interactions between aromatic rings to take effect, which means that the aromatics pollutants, such as nitroaromatics and azo-dyes in water should be easily adsorbed by polystyrene carriers [ 32 ]. Juan Wang [ 33 ] found that polystyrene can accumulate phenanthrene, nitrobenzene, and naphthalene in water.…”

“…Furthermore, polystyrene microplastics had a size effect on the adsorption of phenanthrene and nitrobenzene [ 34 ]. Moreover, the polystyrene microspheres loaded zero-valent iron had good potential application in the reductive degradation and emergency rescue of nitrobenzene contamination [ 32 ]. However, it is inconvenient to separate polystyrene from the emulsion after polymerization for its small size.…”