Abstract

A new material, polyacrylic acid-b-polyptyrene (PAA-b-PS) covered Ni/Fe nanoparticles (PAA-b-PS-nZVI-Ni), was developed and evaluated for the selective dechlorination of 1,1,1-trichloroethane (1,1,1-TCA) in the presence of potential interferents. The average size of the PAA-b-PS coated Fe/Ni bimetallic nanoparticles was approximately 50 nm, which resulted from agglomeration prevention by PAA-b-PS. The removal efficiency of 1,1,1-TCA by an optimal dose with a 1.0 g/L Fe/Ni (Ni/Fe = 2 wt%) and 0.5 g/L PAA-b-PS-coated concentration was higher (87.5%) than that of bare Fe/Ni (60%). The pseudo-first-order rate constant (K_obs) of 1,1,1-TCA removal by PAA-b-PS-nZVI-Ni was 0.0142 min⁻¹ within 240 min. Comparatively, the K_obs values of 1,1,1-TCA removal by other materials (Fe, pure bimetallic Fe/Ni, PAA-b-PS-Fe) were only 0.003, 0.0052 and 0.0103 min⁻¹, respectively. The 1,1,1-TCA removal efficacy by PAA-b-PS-nZVI-Ni showed no obvious gap regardless of pH or various common inorganic anions (NO₃⁻, HCO₃⁻ and SO₄²⁻) at different concentrations. However, humic acid (HA) had great influence on the degradation of 1,1,1-TCA. In conclusion, PAA-b-PS-covered Ni/Fe nanoparticles with its selectivity high effectiveness could be used as one remedial agent for the degradation of 1,1,1-TCA in water.

摘要

一种新材料，聚丙烯酸-b-聚芘（PAA-b-PS）覆盖的镍/铁纳米粒子（PAA-b-PS-nZVI-Ni），被开发和评估用于1,1,1-三氯乙烷的选择性脱氯(1,1,1-TCA) 在存在潜在干扰物的情况下。PAA-b-PS 包覆的 Fe/Ni 双金属纳米粒子的平均尺寸约为 50 nm，这是由于 PAA-b-PS 防止团聚所致。使用 1.0 g/L Fe/Ni (Ni/Fe = 2 wt%) 和 0.5 g/L PAA-b-PS 涂层浓度的最佳剂量对 1,1,1-TCA 的去除效率更高（87.5 %) 比裸 Fe/Ni (60%)。PAA-b-PS-nZVI-Ni 去除 1,1,1-TCA的伪一级速率常数 (K _obs )在 240 分钟内为 0.0142 min ^-1。相比之下，K _obs其他材料（Fe、纯双金属 Fe/Ni、PAA-b-PS-Fe）去除 1,1,1-TCA 的值分别仅为 0.003、0.0052 和 0.0103 min ^-1。PAA-b-PS-nZVI-Ni 对 1,1,1-TCA 的去除效果与 pH 值或各种常见无机阴离子（NO ₃ ^-、HCO ₃ ^-和 SO ₄ ^2-）在不同浓度下均无明显差异。然而，腐植酸 (HA) 对 1,1,1-TCA 的降解有很大影响。综上所述，PAA-b-PS 覆盖的 Ni/Fe 纳米颗粒具有选择性和高效性，可作为一种修复剂来降解水中的 1,1,1-TCA。