Abatement of Industrial Sulfonic Pollutants by Ozone and UV Radiation

The application of advanced oxidation technologies to the treatment of effluents from the pulp and paper industry: a review

“…Furthermore, why p-toluenesulfonic acid showed a slower degradation rate than other lignin derivatives was explained by the strong deactivating effect of its sulfonic group (Amat et al 2004). In short, the composition of the pulp and paper industrial wastewater, which is mediated by the papermaking process itself, including raw materials and chemicals being used, is clearly determining the final oxidation treatment efficiency.…”

“…Regarding the conditions under which ozonation was performed, several authors have reported that ozone resulted more effective in basic media (Amat et al 2004;Amat et al 2005b;Bijan and Mohseni 2005;Sevimli 2005;Wang et al 2004), just as it was expected due to the more effective generation of hydroxyl radicals, which is a better oxidizing agent than molecular ozone (Bijan and Mohseni 2005;Glaze et al 1987); although working under basic conditions also implies bearing with the presence of possible scavengers like carbonate or bicarbonate (Barndõk et al 2012;Bijan and Mohseni 2005). Putting it all together, no significant different treatment effectiveness was found between pH = 9 and 11 (Bijan and Mohseni 2005), but a significant lower treatment efficiency was addressed when pH was adjusted to neutral (Wang et al 2004).…”

“…In fact, according to Salokannel et al (2007), purification results are not expected to be influenced by the feeding gas ozone concentration; they rather depend on the ozone dose that is applied to water, whereas the feeding gas ozone concentration and its mass transfer rate to the solution have a straight effect on the reaction time required to reach the desired ozone dose in water. Correspondingly, reaction rate is clearly dependent on ozone availability (Amat et al 2004) and reaction time (Amat et al 2003). Furthermore, in an enlightening work, Kreetachat et al (2007) measured mass transfer to water when applying different ozone feeding rates, reporting that the volumetric mass transfer coefficient increases from 0.22 to 0.55 min -1 when the ozone feeding rate increases from 1 to 4 L·min -1 , so the oxidation rate increases at a higher feeding rate because the driving force transferring ozone to the solution is greater.…”

“…That is, COD removal increased from 3 to 24% when ozone treatment was photo-assisted at pH=6 (Amat et al 2005b).In fact, these authors previously addressed that this synergetic treatment efficiency may only occur under acidic pH because ozone itself decomposes to OH· radicals under basic conditions, and irradiation would therefore be unnecessary (Amat et al 2004). In addition, Ledakowicz et al (2006) also reported that this treatment improved the removal of the COD from resin acids; results being particularly better at higher temperature (80 ºC).…”

“…acetic and formic acids) in small quantities (Gullichsen and Fogelholm 1999;Sundholm 1999). In addition, chemical pulping processes have been reported to generate more than 40% low biodegradable organics within the total organic matter of the effluent (Dahlman et al 1995); and particularly, sulphite processes also produce low biodegradable sulfonic compounds as by-products (Amat et al 2004;Gregor et al 1997).…”