Gamma-ray, X-ray and Electron Beam Based Processes

Application of Radiation Technology in Removing Endocrine Micropollutants from Waters and Wastewaters—A Review

“…There have been many attempts at economic analyses concerning both the investment costs and the cost of treating 1 m 3 of water/wastewater. Depending on the adopted initial conditions, the costs of treatment of 1 m 3 ranged from USD 0.075 to 3.17 [123]. Particularly promising are the results indicating an increase in biodegradability after the application of small doses of 1-2 kGy of ionizing radiation.…”

Liquid Chromatography-Mass Spectrometry studies on molecular structure of melatonin after Co-60 gamma irradiation

“…Although it seems due to π-excessive ring, pyrrole ring in MLT is more attractive for • OH; another mechanism for MLT oxidation by • OH, has been proposed by Allegra, et al, in which another part of MLT is affected and a three cyclic compound is formed [13]. atom donation in water is slow, the lifetime of eaq is relatively high [14].…”

“…Also, hydroxyl radical ( • OH) is in an acid-base equilibrium with pK a =11.8 with the O ·species. The rate constant of forward equilibrium reaction from hydroxyl to radical oxygen was reported to be 1.3×10 10 M -1 sec -1 ; and the rate constant for the reverse reaction equals to 7.9×10 7 M -1 sec -1 [14].…”

“…This can be related to radical dissociation of water molecules due to irradiation. It has been showed that the oxidation/reduction properties of radicals resulting from the radiolysis of water are due to the following: a) The impact of • OH radical, which is a strong oxidant, and its oxidation potential varies due to solution pH from 11.9V for • OH/ -OH to 12.72 V for • OH, H + /H 2 O and; b) hydrated electron (eaq ) which is a powerful reducing agent in neutral and alkaline solutions with reduction potential of 22.87V [14]. In acidic media, • H is the major reducing agent with reduction potential of 22.31V.…”

“…active species react with other molecules in water solution; and as an interesting fi nding, unlike other oxidizing or reducing processes, irradiation of water solution of a chemical might produce both the chemical's oxidation and reduction products[14,15].According to data collected from the ESI-MS spectrum of compound III (Figure 6), its molecular weight equals to 276amu. The ions with the m/z 299 and 575 correspond to M′+Na and 2M′+Na, respectively.…”