Ni removal from aqueous solutions by chemical reduction: Impact of pH and pe in the presence of citrate
學年 105
學期 1
出版（發表）日期 2016-12-15
作品名稱 Ni removal from aqueous solutions by chemical reduction: Impact of pH and pe in the presence of citrate
作品名稱（其他語言）
著者 Chi-Wang Li; Jui-Hsuan Yu; Yang-Min Liang; Yi-Hsuan Chou; Hyung-June Park; Kwang-Ho Choo; Shiao-Shing Chen
單位
出版者
著錄名稱、卷期、頁數 Journal of Hazardous Materials 320, p.521-528
摘要 The chemical precipitation of Ni ions from industrial wastewater at alkaline pH values creates waste chemical sludge (e.g., Ni(OH)2). We herein focused on Ni removal via chemical reduction using dithionite, by converting Ni(II) to its elemental or other valuable forms. Without the presence of a chelator (e.g., citrate), the nickel reduction efficiency increased with increasing dithionite:Ni molar ratio, reaching ⿼99% at ratios above 3:1. The effect of pH on Ni reduction was in agreement with the standard redox potentials (pe0) of dithionite, which became more negative with an increase in pH leading to greater Ni reduction efficiencies. With the formation of Ni-citrate chelates, however, the Ni reduction deteriorated. Elevated pH and temperature improved nickel reduction, due to the greater reducing power of dithionite. The optimal pH value for Ni(II) reduction was found to be ⿼8. Injecting Cu seed particles enhanced the rate and amount of Ni reduced. NiS and Ni3S2 were identified in the crystal of the resulting solids by X-ray crystallography, and the presence of elemental Ni was explained by X-ray photoelectron spectroscopy. The chemical reduction of actual printed circuit board wastewater with the dithionite:Ni(II) molar ratio dose of 12:1 retrieved ⿼99% nickel after 30-min reaction at 40 °C.
關鍵字 Chemical reduction;Nickel;Citric acid;Dithionite;Complex
語言 en
ISSN 1873-3336
期刊性質 國外
收錄於 SCI
產學合作
通訊作者 Chi-Wang Li;Kwang-Ho Choo
審稿制度 是
國別 NLD
公開徵稿
出版型式 ,電子版
相關連結

機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/108249 )