Degradation of natural organic matter in surface water using vacuum-UV irradiation

Degradation of 2,4-dihydroxibenzoic acid by vacuum UV process in aqueous solution: Kinetic, identification of intermediates and reaction pathway

“…The HO • radicals formed in large amount within the V-UV process, are the major actors in the degradation of the 2,4-DHBA, leading after several steps to total mineralization as expressed in reaction (12) and as demonstrated in this paper.…”

“…Absorption of water increases steadily from approximately 190 to 120 nm and its electronic excitation in this spectral region induces its homolysis leading to the production of a large amount of hydrogen radicals (H • ) and HO • [7]. For this purpose, vacuum ultra-violet (V-UV) lamps have been used for water homolysis in water treatment [8][9][10][11][12] and gaseous stream treatment [13][14][15][16]. This kind of lamp is a very interesting and powerful source of HO • radicals [7,17] with a considerable potential for application.…”

A study of enhanced performance of VUV/UV process for the degradation of micropollutants from contaminated water

“…Herein, to partly investigate the • OH scavenging effect of the degradation intermediates, the first generation by-products of the model contaminant were included in the reaction scheme shown in Table 1. Also, it is known that the presence of natural organic matter (NOM), ubiquitous in water sources, greatly affects the efficiency of the VUV/UV process [8,10,22]. This is mainly attributed to NOM's affinity to react with • OH (scavenging effect) and reduce its availability to react with the target pollutant.…”

“…For example, Imoberdorf and Mohseni [8,10] presented a complete kinetic model for the description of VUV/UV induced degradation of a model herbicide (2,4-dichlorophenoxyacetic acid) in absence and presence of the main • OH scavengers (e.g., NOM, alkalinity). For both conditions, the authors demonstrated a good agreement between the model predictions and experimental results obtained from a mixed batch VUV/UV reactor.…”

Advanced reduction of Cr(VI) in real chrome-plating wastewater using a VUV photoreactor: Batch and continuous-flow experiments

“…The vacuum-UV (VUV) method is an advanced homogeneous process in which oxidizing radical species of Å H and Å OH and reducing free electrons are generated through homolysis and photo-ionization of water molecules using a UV lamp that emits radiation at a wavelength of 185 nm [30][31][32][33]. Both oxidation and reduction reactions can occur in the VUV process.…”