Evaluation of highly active nanoscale zero-valent iron coupled with ultrasound for chromium(VI) removal》.pdfVIP

Chemical Engineering Journal 281 (2015) 155–163 Contents lists available at ScienceDirect Chemical Engineering Journal journal homepage: www.else /locate/cej Evaluation of highly active nanoscale zero-valent iron coupled with ultrasound for chromium(VI) removal Xiaobin Zhou, Bihong Lv, Zuoming Zhou, Wenxin Li, Guohua Jing ⇑ Department of Environmental Science Engineering, Huaqiao University, Xiamen, Fujian 361021, China h i g h l i g h t s Nanoscale zero-valent iron coupled with ultrasound was proposed for Cr(VI) removal. The Cr(VI) removal rate and efficiency were greatly enhanced by ultrasound. The mechanism of Cr(VI) removal in the US-nZVI system was discussed. The reaction followed two-parameter pseudo-first-order model, and Ea was 21.53 kJ mol1. a r t i c l e i n f o a b s t r a c t Article history: An integrated technology consisting of highly active nanoscale zero-valent iron (nZVI) and ultrasound Received 21 April 2015 (US) was proposed for chromium(VI) removal. The parameters affecting Cr(VI) removal, such as the ultra- Received in revised form 18 June 2015 sonic frequency, power, reaction temperature, initial pH and Cr(VI) concentration, were investigated. Accepted 19 June 2015 Based on the investigation and the characterization of the nZVI particles, the removal mechanism of Available online 26 June 2015 Cr(VI) in US-nZVI system is proposed. Ultrasound not only contributed to an increase on available surface