College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
Bioresour Technol. 2018 May;256:247-253. doi: 10.1016/j.biortech.2018.02.022. Epub 2018 Feb 7.
The HNO treatment was used to chemically modify the biochars produced from wheat straw (WH) and cow manure for U(VI) removal from aqueous solution. Macroscopic experiments proved that the enrichment of U(VI) on the biochars was regulated by surface complexation and electrostatic interactions. FTIR and XPS analyses confirmed that the highly efficient adsorption of U(VI) was due to the carboxyl groups on the biochar surfaces. The reducing agents of the R-CHOH groups facilitated U(VI) adsorption on the untreated biochars. Owing to the higher contents of surface COO groups and more negative surface charge, the modified biochars showed enhanced U(VI) adsorption ability than the untreated ones. The maximum adsorption capacity of U(VI) by the oxidized WH was calculated to be 355.6 mg/g at pH 4.5 and 298 K, which was an improvement of 40 times relative to the untreated WH and was higher than that of most carbon-based adsorbents.
采用 HNO3 处理对小麦秸秆（WH）和牛粪生物炭进行化学改性，以去除水溶液中的 U(VI)。宏观实验证明，表面络合和静电相互作用调节了生物炭上 U(VI)的富集。FTIR 和 XPS 分析证实，生物炭表面的羧基基团是高效吸附 U(VI)的原因。R-CHOH 基团的还原剂促进了未经处理的生物炭对 U(VI)的吸附。由于表面 COO 基团含量较高和表面负电荷更多，改性生物炭的 U(VI)吸附能力比未经处理的生物炭更强。在 pH 4.5 和 298 K 下，氧化 WH 对 U(VI)的最大吸附容量计算为 355.6 mg/g，与未经处理的 WH 相比提高了 40 倍，高于大多数基于碳的吸附剂。
