title: Enhancement of saccharin removal from aqueous solution by activated carbon adsorption with ultrasonic treatment.
abstract: This study investigates the use of ultrasonication as a pretreatment process and its effect on the adsorption characteristics of saccharin onto activated carbon (AC). Ultrasonic decomposition of saccharin was performed at a frequency of 500 kHz under argon and O2/N2 (20/80 vol%) atmospheres. Adsorption was carried out using a commercial activated carbon. The behavior of total organic carbon (TOC) during ultrasonication was investigated. Saccharin removal after 180 min of ultrasonication under Ar and O2/N2 atmospheres are 38% and 26%, respectively, while the amount of saccharin removed by activated carbon adsorption without US pretreatment is 40% after 16 h. After 16 h of AC adsorption with 180 min of ultrasonic pretreatment under Ar and O2/N2 atmospheres, both removal ratios increased to 75%. These results indicated that the pretreatment of sonication under O2/N2 leads to the increase in the amount of saccharin adsorbed on AC. On the other hand, the TOC removal by decomposition by ultrasound is not more than 5% in both Ar and O2/N2 atmospheres after 180 min ultrasonication. However, the TOC removal increased to 54% and 69% after 16 h of adsorption of saccharin pretreated by ultrasonication for 180 min under Ar and O2/N2 atmospheres, respectively. About 13% and 16% TOC removal in Ar and in O2/N2, respectively, were achieved due to adsorption of the by-products. It is considered that the improvement in TOC removal is also brought about by the formation of the by-products that were adsorbed onto AC.
authors.affiliation: Research Center for Advanced Waste and Emission Management, Department of Energy Engineering and Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Eileen C
authors.initials: EC
authors.lastname: Bernardo
authors.forename: Tadashi
authors.initials: T
authors.lastname: Fukuta
authors.forename: Takafumi
authors.initials: T
authors.lastname: Fujita
authors.forename: Erwin P
authors.initials: EP
authors.lastname: Ona
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kojima
authors.forename: Hitoki
authors.initials: H
authors.lastname: Matsuda
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods*; D012439:Saccharin / Q000737:chemistry* / Q000302:isolation & purification* / Q000528:radiation effects; D012996:Solutions; D013010:Sonication; D014462:Ultrafiltration / Q000379:methods*; D014867:Water / Q000737:chemistry*
chemical_list: D012996:Solutions; D014867:Water; D002606:Charcoal; D012439:Saccharin