Oh Seok-Young, Seo Yong-Deuk, Ryu Kwang-Sun, Park Da-Jeong, Lee Seung-Hun
Department of Civil and Environmental Engineering, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 44610, South Korea.
Environ Sci Process Impacts. 2017 May 24;19(5):711-719. doi: 10.1039/c7em00035a.
A novel biochar-coated zero-valent iron [Fe(0)], which was synthesized with rice straw and Fe(0), was applied to remove nitro explosives (2,4,6-trinitrotoluene and hexahydro-1,3,5-trinitro-1,3,5-triazine) and halogenated phenols (2,4-dibromophenol and 2,4-difluorophenol) from contaminated waters. Due to the presence of biochar on the outside, the removal of nitro explosives and halogenated phenols was significantly enhanced via sorption. The sorbed contaminants were further transformed into reductive products, indicating that the inner Fe(0) played the role of a reductant in the biochar-coated Fe(0). Compared to direct reduction with Fe(0), the reductive transformation with biochar-coated Fe(0) was markedly enhanced, suggesting that the biochar in biochar-coated Fe(0) may act as an electron transfer mediator. Further experiments showed that the surface functional groups of biochar were involved in the catalytic enhancement of electron transfer. Our results suggested that biomass could be used to synthesize a novel sorbent and catalyst for treating redox-sensitive contaminants in natural and engineered systems.
一种由稻草和零价铁合成的新型生物炭包覆零价铁[Fe(0)]，被用于从受污染水体中去除硝基炸药（2,4,6-三硝基甲苯和六氢-1,3,5-三硝基-1,3,5-三嗪）和卤代酚（2,4-二溴苯酚和2,4-二氟苯酚）。由于外部存在生物炭，通过吸附作用，硝基炸药和卤代酚的去除率显著提高。被吸附的污染物进一步转化为还原产物，这表明内部的Fe(0)在生物炭包覆的Fe(0)中起到了还原剂的作用。与直接用Fe(0)还原相比，生物炭包覆的Fe(0)的还原转化作用明显增强，这表明生物炭包覆的Fe(0)中的生物炭可能充当电子转移介质。进一步的实验表明，生物炭的表面官能团参与了电子转移的催化增强过程。我们的结果表明，生物质可用于合成一种新型吸附剂和催化剂，用于处理自然和工程系统中对氧化还原敏感的污染物。
