Ozonation and combined ozone/H2O2, UV/ozone and UV/H2O2 for treatment of fuel oxygenates MTBE, ETBE, TAME, and DIPE from water – a comparison of removal efficiencies

Abstract

Methyl tert-butylether (MTBE) used as fuel oxygenate poses problems for water suppliers since it is persistent in the aquatic environment and the removal efficiency by conventional water treatment methods (aeration or activated carbon filtration) is rather low. Substitution by other ether compounds such as ethyl tert-butylether (ETBE), tert-amylmethylether (TAME) or di-isopropylether (DIPE) is discussed, however, their environmental behaviour is similar to that of MTBE. Experiments investigating the elimination efficiency of AOP were carried out in tap water and water from Lake Constance. The elimination efficiency for all treatment processes was found to follow the order: MTBE << TAME approximately equal ETBE < DIPE For all compounds under investigation, neither pure ozonation nor UV irradiation yield a considerable concentration decline. Only the formation of highly reactive OH radicals shows a potential for removing the ethers from water. Therefore the addition of H2O2 in equimolar ratio prior to ozone admixing proved to be quite efficient. The application of combined UV/H2O2 showed good results in all cases; the best concentration decline was achieved with UV/ozone. The rate of elimination of the three substitutes for MTBE (ETBE, TAME and DIPE) is higher in all processes; nevertheless, no complete removal could be achieved. Therefore, from the point of view of water suppliers, the use of other ethers as substitute for MTBE is posing the same problems as MTBE.

Studies on the formation of formaldehyde during 2-ethylhexyl 4-(dimethylamino)benzoate demethylation in the presence of reactive oxygen and chlorine species

“…Advanced oxidation processes (AOPs) are efficient water treatment methods utilizing reactive oxygen species generation. Some examples of frequently used and studied AOPs are TiO 2 /UV (Hupka et al 2006;Thiruvenkatachari et al 2008), H 2 O 2 , H 2 O 2 /UV, O 3 , O 3 /UV (Baus et al 2007;Souza et al 2016), Fe 2+ /H 2 O 2 , Fe 3+ /H 2 O 2 (Gaca et al 2005;Tong et al 2011;Khankhasaeva et al 2012), Fe 3+ /H 2 O 2 /UV (Kumar et al 2008;Diagne et al 2009;Li et al 2012b;Topac and Alkan 2016;Tsoumachidou et al 2016) and Fe 2+ /UV/S 2 O 8 2− (Khan et al 2013;Brienza et al 2014;Xue et al 2016). Unfortunately, in some cases, AOPs fail in formaldehyde elimination or even contributes to its generation (Can and Gurol 2003;Wert et al 2007;Trenholm et al 2008;Tripathi et al 2011;Li et al 2012a).…”

Modified Sequencing Batch Airlift Reactor Capability in MTBE Removal

“…There are various physical, chemical, and biological methods for MTBE treatment. Ozone ultrasonic irradiation [8], hybrid oxidation [11], ozonation [20], UV/chlorine advanced oxidation process [14], electro-photocatalytic processes such as TiO2 [21,23,27], ZnO-AgCl nanocomposite photocatalyst [18] and oxidation with per-sulfate to produce activated carbon for the removal of MTBE [10] are some of the methods used to reduce and eliminate this product. The most common methods of removing MTBE from drinking water are aeration [13], application of natural and modified diatoms [2,3,33] optical dispersion with nano-zeolite combinations ZnO [34], adsorption by activated carbon [26], advanced oxidation processes (using a fluoride ion, O3, and H2O2), Fenton and pseudoFenton [5,12], UV-Fenton [17] and using H2O2in the presence of Fe-zeolite catalysts [24].…”