Issue 8, 2018, Issue in Progress

Application of a novel definitive screening design to in situ chemical oxidation of acid orange-II dye by a Co2+/PMS system

Abstract

In this work, a novel definitive screening design (DSD) was initially used to investigate the in situ chemical oxidation of acid orange-II (AO II) dye using a homogeneous cobalt-catalyzed peroxymonosulfate (Co2+/PMS) system. Experiments were performed in a batch reactor using a synthetic AO II solution containing cobalt ions, humic acid (HA) and five electrolyte salts (NaCl, NaNO3, NaHCO3, Na2SO4 and NaH2PO4). The effects of nine operating variables on AO II degradation: NaCl concentration (0–20 mM), NaH2PO4 concentration (0–20 mM), NaHCO3 concentration (0–20 mM), NaNO3 concentration (0–20 mM), Na2SO4 concentration (0–20 mM), HA concentration (0–40 mg L−1), PMS concentration (2–10 mM), AO II concentration (0–100 mg dm−3) and Co2+ concentration (0–1.36 mM), were investigated. Analysis of a DSD model revealed that only four variables were statistically significant. Besides, our results indicated that there were no significant interactive effects between the five anions employed. Thereafter, a central composite rotatable design (CCRD) was adopted to further optimize these significant variables. A CCRD model describing AO II conversion as a function of PMS concentration, NaCl concentration and Co2+ concentration was then constructed and used to explore the final optimal operating conditions. As a consequence, the combination of DSD and CCRD allowed reducing the number of experiments from over 600 to only 39. Lastly, a plausible reaction sequence concerning the oxidation of AO II in the Co2+/PMS/Cl system was also proposed. The route of AO II oxidation involved hydroxylation and chlorination, signifying the roles of both sulfate radicals and active chlorine species.

Graphical abstract: Application of a novel definitive screening design to in situ chemical oxidation of acid orange-II dye by a Co2+/PMS system

Article information

Article type
Paper
Submitted
19 Dec 2017
Accepted
13 Jan 2018
First published
22 Jan 2018
This article is Open Access
Creative Commons BY license

RSC Adv., 2018,8, 3934-3940

Application of a novel definitive screening design to in situ chemical oxidation of acid orange-II dye by a Co2+/PMS system

C. Zhang, W. Chen, J. Xian and D. Fu, RSC Adv., 2018, 8, 3934 DOI: 10.1039/C7RA13446K

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements