Rapid dye degradation with reactive oxidants generated by chloride-induced peroxymonosulfate activation
- 775 Downloads
Transition-metal is known to catalyze peroxymonosulfate (PMS) decomposition to produce sulfate radicals. Here we report reactions between PMS and chloride, without a need of transition metals, also can be used to degrade organic dye pollutant (Rhodamine B, (RhB)). Some important operating parameters, such as dosages of PMS and Cl−, pH of solution, temperature, ionic strength, and several common cations, were systematically investigated. Almost complete decoloration of RhB was achieved within 5 min ([PMS] = 0.5 mM, [Cl−] = 120 mM, and pH 3.0), and RhB bleaching rate increased with the increased dosages of both PMS and chloride ion, following the pseudo-first-order kinetic model. However, the total organic carbon (TOC) removal results demonstrated that the decoloration of RhB was due to the destruction of chromophore rather than complete degradation. RhB decoloration could be significantly accelerated due to the high ionic strength. Increasing of the reaction temperature from 273 K to 333 K was beneficial to the RhB degradation, and the activation energy was determined to be 32.996 kJ/mol. Bleaching rate of RhB with the examined cations increased with the order of NH4 + < Na+ < K+ < Al3+ < Ca2+ < Mg2+. Some major degradation products of RhB were identified by GC-MS. The present study may have active technical implications for the treatment of dyestuff wastewater in practice.
KeywordsStoichiometric reaction Ionic strength Activation energy Cations System parameters
The authors would like to acknowledge the financial support from the Fundamental Research funds for Central Universities Central (12D11317) and State Key Laboratory of Pollution Control and Resource Reuse Foundation (No. CRRF11023). This work was partially supported by National Science Foundation of China (Nos. 21007009, 41273108) and “Chen Guang” project (10CG34).
- Guillard C, Lachheb H, Houas A, Mohamed K, Elaloui E, Herrmann JM (2003) Influence of chemical structure of dyes, of pH and of inorganic salts on their photocatalytic degradation by TiO2 comparison of the efficiency of powder and supported TiO2. J Photochem Photobiol A: Chem 158:27–36CrossRefGoogle Scholar
- Yu XY, Bao ZC, Barker JR (2004) Free radical reactions involving Cl•, Cl2 −•, and SO4 −• in the 248 nm photolysis of aqueous solutions containing S2O8 2- and Cl− J Phys Chem A 108:295–308Google Scholar