Details

Autor(en) / Beteiligte

• Zhou, Shuangxi
• Du, Zhiling
• Li, Xiuwen
• Zhang, Yunhai
• He, Yide
• Zhang, Yongjun

Titel

Degradation of methylene blue by natural manganese oxides: kinetics and transformation products

Ist Teil von

• Royal Society open science, 2019-07, Vol.6 (7), p.190351-190351

Ort / Verlag

England: The Royal Society

Erscheinungsjahr

2019

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• In this study, natural manganese oxides (MnO ), an environmental material with high redox potential, were used as a promising low-cost oxidant to degrade the widely used dyestuff methylene blue (MB) in aqueous solution. Although the surface area of MnO was only 7.17 m g , it performed well in the degradation of MB with a removal percentage of 85.6% at pH 4. It was found that MB was chemically degraded in a low-pH reaction system and the degradation efficiency correlated negatively with the pH value (4-8) and initial concentration of MB (10-50 mg l ), but positively with the dosage of MnO (1-5 g l ). The degradation of MB fitted well with the second-order kinetics. Mathematical models were also built for the correlation of the kinetic constants with the pH value, the initial concentration of MB and the dosage of MnO . Furthermore, several transformation products of MB were identified with HPLC-MS, which was linked with the bond energy theory to reveal that the degradation was initiated with demethylation.