Degradation of neonicotinoid insecticides by different advanced oxidation processes and studying the effect of ozone on TiO2 photocatalysis

Degradation of cypermethrin, malathion and dichlorovos in water and on tea leaves with O3/UV/TiO2 treatment

“…For cypermethrin, however, it was less effectively removed under alkaline condition in water. This is similar with the results of Cernigoj et al (2007) on thiacloprid degradation. They summed up that the faster self-decomposition of O 3 under alkaline condition led to the loss of synergism between UV/TiO 2 and O 3 .…”

“…O 3 /TiO 2 /UV was highly efficient in elimination of a great number of organic pollutants (Cernigoj, Stangar, & Trebse, 2007;Kopf, Gilbert, & Eberle, 2000;Piera et al, 2000;Yang, Ma, Qin, & Zhai, 2007). It was reported that chemical oxidation process can work through three mechanisms in the O 3 /UV/TiO 2 or O 3 /UV system: direct oxidation by UV irradiation (photolysis), direct oxidation by ozone (ozonation), and oxidation by free radicals (mainly OH) 3.…”

Photodegradation of neonicotinoid insecticides in water by semiconductor oxides

“…This behaviour is in accordance with other studies performed on neonicotinoids. However, the apparent rate constants and half-lives calculated within our study differ in comparison to other photocatalytic works, due to the different experimental setups and conditions such as photon flux, photocatalyst concentration and Na 2 S 2 O 8 concentration (Malato et al 2001;Cernigoj et al 2007;Kitsiou et al 2009;Zabar et al 2012). Therefore, a comparison of photocatalytic degradation of NIs with ZnO and TiO 2 was evaluated at equal level of photon absorption following the method proposed by Dolat et al (2012).…”

“…In recent years, the photocatalytic degradation of neonicotinoids in aqueous solution has been studied using TiO 2 as catalyst (Malato et al 2001;Cernigoj et al 2007;Cao et al 2008;Kitsiou et al 2009;Bernabeu et al 2011;Guzsvány et al 2012;Zabar et al 2012;Mir et al 2013). However, the effect of ZnO for the removal of these insecticides from water has received little attention.…”

Influence of calcination temperature on TiO2 nanotubes’ catalysis for TiO2/UV/O3 in landfill leachate solution

“…Being one of these, landfill leachate cannot be treated with biological methods alone. A promising way of degrading the biologically and chemically stable molecules is the application of advanced oxidation processes (AOPs) that can in situ produce hydroxyl radicals under mild experimental conditions [1] . Furthermore, the combination of two or more AOPs expectedly enhances free radical generation, which eventually leads to higher oxidation rates [2] .…”