The long-term stability of calcium arsenates:Implications for phase transformation and arsenic mobilization

查看全文 作　　者：Danni [1]Zhang;Shaofeng [1]Wang;Ying [1]Wang;Mario [2]A.Gomez;Yongfeng [1]Jia

机构地区：[1]Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China;[2]Institute of Environmental Protection, Shenyang University of Chemical Technology, Shenyang 110142, China

出　　处：《Journal of Environmental Sciences》索引2019年第31卷第10期,共13页

基　　金：supported by the National Natural Science Foundation of China (Nos. 41530643, 41673130 and 41877393);the National Key R&D Program of China (No. 2017YFD0800301);the Chinese Academy of Sciences (No. QYZDJ-SSW-DQC038) 摘　　要：It is well known that calcium arsenates may not be a good choice for arsenic removal and immobilization in hydrometallurgical practices.However,they are still produced at some plants in the world due to various reasons.Furthermore,calcium arsenates can also naturally precipitate under some specific environments.However,the transformation process of poorly crystalline calcium arsenates(PCCA)and the stability of these samples under atmospheric CO2 are not yet well understood.This work investigated the transformation process of PCCA produced by using different neutralization reagents(CaO vs.NaOH)with various Ca/As molar ratios at pH 7-12 in the presence of atmospheric CO2.After aging at room temperature for a period of time,for samples neutralized with NaOH and precipitated at pH 10 and 12,release of arsenic back into the liquid phase occurred.In contrast,for the samples precipitated at pH 8,the aqueous concentration of arsenic was observed to decrease.XRD,Raman,and SEM results suggested that the formation of various types of crystalline calcium carbonates and/or calcium arsenates controls the arsenic behavior.Moreover,the application of lime may enhance the stability of the generated PCCA.However,no matter what neutralization reagent is used,the stability of the generated PCCA is still of concern. 关键词：ARSENIC PRECIPITATE CALCIUM Stability CO2

相关文献

参考文献（46）
引证文献（14）
耦合文献（0）

参考文献(46)

引证文献(14)

互联网出版许可证新出网证(渝)字10号全国400电话 - 免长途话费

The long-term stability of calcium arsenates:Implications for phase transformation and arsenic mobilization

参考文献(46)

引证文献(14)

用户提示