Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; College of Life & Environmental Sciences, Huangshan University, Huangshan 245041, China.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
Sci Total Environ. 2018 Mar;616-617:1298-1306. doi: 10.1016/j.scitotenv.2017.10.188. Epub 2017 Nov 2.
Hydrated manganese oxide (HMO) nanoparticles were impregnated into a peanut shell-derived biochar (BC) to obtain a remarkable nanocomposite adsorbent, HMO-BC, which overcomes the technical barriers of singly applying either HMO or BC in practical heavy metal-containing wastewater treatment. HMO-BC can effectively sequestrate Pb(II) and Cd(II) in a wide pH range of 3-7 and exhibited more preferable sorption than bare BC in the presence of high-level competing cations. BC also significantly lowered the Mn leaching at acidic pH. Fixed-bed column adsorption tests showed that the effective treatment volume of HMO-BC for a simulated Pb(II)- or Cd(II)-laden wastewater is about 4-6 times higher than that of the BC host. In addition, HMO-BC was effective in removing Pb(II) from a real Pb-containing electroplating wastewater to discharge limit (0.2mgL) with treatable volume of 525BV, much higher than that of the bare BC (60BV). More importantly, the saturated HMO-BC can be thoroughly regenerated for repeated uses without any observable capacity loss. Such attractive results of HMO-BC were attributed to the complementary effect of its two components. The embedded HMO nanoparticles provide preferable capture of target cations through specific inner-sphere complexation, as illustrated by XPS spectra of Pb 4f and O1s, while the non-diffusive negatively charged oxygen-containing groups bound to BC facilitate the pre-enrichment and permeation of Pb(II) and Cd(II) cations into the pore channels prior to their preferable sorption through the Donnan membrane effect.
水合氧化锰 (HMO) 纳米颗粒被浸渍到花生壳衍生的生物炭 (BC) 中,得到一种显著的纳米复合材料吸附剂 HMO-BC,克服了单独应用 HMO 或 BC 在实际含重金属废水处理中的技术障碍。HMO-BC 可以在 pH 值为 3-7 的宽范围内有效螯合 Pb(II) 和 Cd(II),并在存在高水平竞争阳离子的情况下比裸 BC 具有更优的吸附性能。BC 还显著降低了酸性 pH 值下的 Mn 浸出。固定床柱吸附试验表明,HMO-BC 对模拟的 Pb(II)或 Cd(II)废水的有效处理体积约为 BC 载体的 4-6 倍。此外,HMO-BC 能够有效地从实际含 Pb 的电镀废水中去除 Pb(II),达到排放限值(0.2mgL),处理体积为 525BV,远高于裸 BC(60BV)。更重要的是,饱和的 HMO-BC 可以通过彻底再生重复使用,而没有任何可观察到的容量损失。HMO-BC 的这些吸引人的结果归因于其两个组成部分的互补效应。嵌入的 HMO 纳米颗粒通过特定的内球络合提供了对目标阳离子的更好捕获,如 XPS 谱图的 Pb 4f 和 O1s 所示,而与 BC 结合的非扩散负电荷含氧基团则有利于 Pb(II)和 Cd(II)阳离子在通过 Donnan 膜效应进行优先吸附之前预富集和渗透到孔道中。