A phenomenological reaction kinetic model for Cu removal from aqueous solutions by zero-valent iron (ZVI). (June 2018)

• Record Type: Journal Article
• Authors: Yoshino, Hiroyuki; Kurosu, Shunji; Yamaguchi, Rina; Kawase, Yoshinori
• Is Part Of: Chemosphere. Volume 200(2018)
• Page Start: 542
• Page End: 553
• Publication Date: 2018-06
• Subjects: Zero-valent iron -- Cu removal -- Reaction kinetic modelling -- Phenomenological model -- Dynamic simulation; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2018.02.127
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Zero-valent iron (ZVI) being an inexpensive and eco-friendly catalyst has drawn great attention in removal of heavy metals from wastewaters. However, quantitative understandings of ZVI processes are significantly deficient. To compensate for the lack of quantitative analyses of removal of heavy metals by ZVI, a phenomenological reaction kinetic model was newly developed for removal of Cu chosen as a typical heavy metal from acidic aqueous solutions by ZVI. The novel kinetic model is based on the adsorption of Cu 2+ and H + onto ZVI surface and subsequent Cu 2+ reduction on ZVI surface and Fe 2+ elution from ZVI. Batch experiments were conducted to elucidate effects of pH and Cu loading on Cu removal by ZVI in acidic aqueous solutions and to validate the proposed phenomenological reaction kinetic model. The quick and complete removals of 1.57 mM Cu were established in the rage of pH 2–5. Although the maximum Cu removal rate was obtained at pH 4, effects of pH were insignificant. In the range of Cu loading from 0.393 to 4.72 mM, almost complete Cu removals were obtained at pH 4 within 35 min. The changes in concentrations of Cu 2+, Fe 2+, H + and dissolved oxygen were strongly linked with each other. They could be successfully simulated by the proposed model with the average correlation coefficient of 0.979. The capability of the phenomenological reaction kinetic model for dynamic simulation of Cu removal by ZVI under acidic conditions was confirmed. Graphical abstract: Highlights: Removal of heavy metals by zero-valent iron (ZVI) was examined. A phenomenological reaction kinetic model for Cu removal by ZVI was developed. Experiments for Cu removal by ZVI were conducted at different pH and Cu loading. The model predictions reasonably fit the experimental data for Cu removal by ZVI. The validation of the kinetic model for removal of heavy metals by ZVI was certified.