School of Chemistry and Materials Engineering, Changshu Institute of Technology, 215500, China; Suzhou Key Laboratory of Functional Ceramic Materials, Changshu Institute of Technology, Changshu, 215500, China.
School of Chemistry and Materials Engineering, Changshu Institute of Technology, 215500, China.
J Environ Manage. 2019 Dec 15;252:109642. doi: 10.1016/j.jenvman.2019.109642. Epub 2019 Oct 3.
Hexametaphosphate intercalated green rust (hexa-P GR) was fabricated by a coprecipitation process in an anaerobic environment to improve the adsorption of hexa-P GR for Cr(VI) and the total Cr under various aqueous conditions. Three kinetic models including the pseudo-first-order, intraparticle, and Elovich were appropriate in describing the adsorption of hexa-P GR towards Cr(VI) and the total Cr. The maximum mono-layer adsorption capacities (mg/g) of hexa-P GR for Cr(VI) at pH of 2 and 7 were 87.64 and 92.25, respectively, with the theoretical maximum capacity (mg/g) of 52.73 being obtained at pH of 7. Some competing cations existing in solutions such as Al, Ca, and Mg would consume more hexa-P GR to remove Cr species. The neutral and weak alkaline environment was conducive to the hexa-P GR reuse, while the strong alkaline environment was beneficial to the removal of the total Cr. The orthogonal variables including the initial pH, the flow rate, and the Cr(VI) concentration all significantly influenced Cr removal. The sequences of reaction pathways referring to the adsorption of hexa-P GR differently occurred in various pH conditions.
六偏磷酸根插层绿色锈（hexa-P GR）通过在厌氧环境中的共沉淀过程制备，以提高其对 Cr(VI)和总 Cr 的吸附性能，在各种水相条件下。三种动力学模型（准一级、内扩散和 Elovich 模型）均适用于描述 hexa-P GR 对 Cr(VI)和总 Cr 的吸附过程。在 pH 值为 2 和 7 时，hexa-P GR 对 Cr(VI)的单层最大吸附容量（mg/g）分别为 87.64 和 92.25，在 pH 值为 7 时，理论最大容量（mg/g）为 52.73。溶液中存在的一些竞争阳离子，如 Al、Ca 和 Mg，会消耗更多的 hexa-P GR 来去除 Cr 物种。中性和弱碱性环境有利于 hexa-P GR 的重复使用，而强碱性环境有利于去除总 Cr。初始 pH 值、流速和 Cr(VI)浓度等正交变量均显著影响 Cr 的去除。不同 pH 值条件下，hexa-P GR 吸附的反应途径顺序不同。
