Identification of ionic liquid breakdown products in an advanced oxidation system

Ionic Liquids: Methods of Degradation and Recovery

“…They demonstrated that hydrogen atoms in the imidazolium ring are oxidized first, and that fragmentation leads to ring opening. This is in agreement with the results obtained by other authors (Czerwicka et al, 2009;Li et al, 2007). They also found that there was no significant influence of either alkyl chain length or anion type on the degradation pathway.…”

“…For this reason, chemical, photochemical or electrochemical oxidation have been put forward as processes for removing from wastewater both non-recoverable ILs and their degradation products (Czerwicka et al, 2009;Li et al, 2007;Pernak & Branicka, 2004;Siedlecka et al, 2008;Stepnowski & Zalewska, 2005;Stolte et al, 2008) (Fig.2.). Biological wastewater treatment is regarded as environmentally very friendly, and some examples of this process are given in this chapter.…”

“…It was found that modification (at least in the first stage of oxidation) occurred in the imidazolium ring, not in the alkyl chain of the molecule. The longer the alkylated cation, the greater the probability of oxidation of the alkyl chain (Czerwicka et al, 2009). The results tallied with those obtained using a Fenton-like system (Siedlecka et al, 2008b) or after biodegradation (Stolte et al, 2008).…”

Role of the chemical structure of ionic liquids in their ecotoxicity and reactivity towards Fenton oxidation

“…In this context, the development of efficient chemical treatments for the degradation of such persistent, nonbiodegradable and/or high toxic compounds has been the focus of considerable research efforts in the last few years [8], principally for water streams with low amounts of IL. Advanced oxidation processes (AOPs), based on the action of hydroxyl radicals at near ambient temperature and pressure, have been proposed as an interesting alternative by several authors [9][10][11][12][13][14][15][16]. Included in the AOPs, Fenton oxidation represents the most realistic approach for the degradation of ILs in water, due to its simplicity and costefficiency [17].…”

Composition and structural effects on the adsorption of ionic liquids onto activated carbon

“…[10][11][12] Different treatments have been investigated for the removal of ILs from aqueous effluents. Among the most studied destructive techniques the advanced oxidation [13][14][15] and biological treatments can be included. [16][17][18] It is important to consider that in the framework of the development of sustainable processes, the ILs recycling aer regeneration or recovery must be envisaged.…”