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Microwave-induced degradation of N-nitrosodimethylamine (NDMA) sorbed in zeolites: Effect of mineral surface chemistry and non-thermal effect of microwave
- Source :
- Journal of Cleaner Production. 174:1224-1233
- Publication Year :
- 2018
- Publisher :
- Elsevier BV, 2018.
-
Abstract
- N-nitrosodimethylamine (NDMA), a highly toxic and carcinogenic disinfection byproduct, cannot be efficiently removed by conventional water treatment processes, while sorption by microporous minerals, followed by destruction with microwave irradiation has been developed as a promising alternative. This work examined the impact of surface cation density and type on sorption of NDMA on dealuminated ZSM-5 zeolites, and on microwave-induced degradation of the sorbed NDMA, as well as the non-thermal effect of microwave. NDMA sorption was found to increase with the framework Si/Al ratio of dealuminated ZSM-5 zeolites (i.e., decreasing density of surface cations), and was also influenced by the type of surface cations. Degradation of the sorbed NDMA proceeded faster with increases in the power level of microwave and in the micropores with higher densities of surface cations, which was attributed to the increases in the number and/or temperature of micro-scale “hot spots” formed by microwave dielectric superheating of the surface cations. The degradation rate of sorbed NDMA was also found to be inversely correlated with the hydration free energy of surface cations present in the zeolite micropores. The apparent activation energy estimated from the temperature dependence of NDMA degradation in the micropores under microwave irradiation was 18.2 kJ/mol, which is much lower than those of typical thermolysis reactions and is indicative of significant contribution from the non-thermal effect of microwave.
- Subjects :
- Renewable Energy, Sustainability and the Environment
Chemistry
Strategy and Management
Inorganic chemistry
Thermal decomposition
Sorption
02 engineering and technology
Microporous material
Activation energy
010501 environmental sciences
021001 nanoscience & nanotechnology
01 natural sciences
Industrial and Manufacturing Engineering
chemistry.chemical_compound
N-Nitrosodimethylamine
Water treatment
0210 nano-technology
Zeolite
Microwave
0105 earth and related environmental sciences
General Environmental Science
Subjects
Details
- ISSN :
- 09596526
- Volume :
- 174
- Database :
- OpenAIRE
- Journal :
- Journal of Cleaner Production
- Accession number :
- edsair.doi...........c42772852fabaf046f8fac4edb9f4a3c