实验室新闻

    科研进展

    实验室公告

    学术活动公告

 
Macroscopic and microscopic investigation of adsorption and precipitation of Zn on gamma-alumina in the absence and presence of As
 点击数:162次 添加时间:  [关闭] [收藏]

作者:Wang, YJ (Wang, Yu-Jun) ; Fan, TT (Fan, Ting-Ting) ; Liu, C (Liu, Cun); Li, W (Li, Wei) ; Zhu, MQ (Zhu, Meng-Qiang) ; Fan, JX (Fan, Jian-Xin) ; Gong, H (Gong, Hua) ; Zhou, DM (Zhou, Dong-Mei) ; Sparks, DL (Sparks, Donald L.) 

 

题目:Macroscopic and microscopic investigation of adsorption and precipitation of Zn on gamma-alumina in the absence and presence of As

 

刊物:CHEMOSPHERE,卷: 178  页: 309-316

DOI: 10.1016/j.chemosphere.2017.03.061

出版年: JUL 2017

 

文章下载:http://ac.els-cdn.com/S0045653517304241/1-s2.0-S0045653517304241-main.pdf?_tid=e85785be-50a1-11e7-8678-00000aacb35d&acdnat=1497404377_690fe28859bb49ea30062e93036e0be3

 

摘要: 

Contaminants zinc (Zn) and arsenate (As) often coexist in soils. However, little is known concerning the impacts of coexisting As on Zn adsorption and precipitation on soil minerals. In the present study, adsorption and precipitation of Zn on gamma-alumina in the absence and presence of arsenate was investigated employing batch experiments and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. Results indicated that Zn formed edge -sharing tetrahedral surface complexes at pH 5.5 and Zn-Al LDH-like (layered double hydroxide) precipitates at pH 7.0 on the surface of gamma-alumina. The presence of arsenate significantly enhanced Zn sorption densities, and remarkably changed its bonding environment. At pH 5.5, SR-XRD (Synchrotron Radiation-based X-ray Diffraction) and EXAFS showed that koettigite-like precipitate were formed in the cosorption of Zn and As on gamma-alumina regardless of the addition sequence of As and Zn. At pH 7.0, when Zn was preequilibrated with gamma-alumina prior to the As introduction, mixed Zn-Al LDH-like and amorphous adamite-like precipitates formed. However, when Zn and As were added simultaneously, only amorphous adamite-like precipitate was observed. Zn inner -sphere complexes and surface ternary complexes y-alumina-As-Zn were the main outcome when As was pre equilibrated firstly. Zn-arsenate precipitates could significantly decrease the concentration of Zn in aqueous solution and decrease the bioavailability and mobilization of Zn in soils. (C) 2017 Elsevier Ltd. All rights reserved.

 

 

 

 

 

 


 

版权所有:中国科学院南京土壤研究所 苏ICP备05004320号 地 址:江苏省南京市北京东路71号 邮编:210008 网站管理