title: Desorption behavior of methylene blue on pyromellitic dianhydride modified biosorbent by a novel eluent: acid TiO2 hydrosol.
abstract: In this study, waste beer yeast powder was modified by pyromellitic dianhydride to improve its adsorption capacities for cationic dye: methylene blue (MB). According to the Langmuir equation, the maximum uptake capacities (q(m)) of the modified biomass for MB was 830.8 mg g(-1), which was about five times than that obtained on the unmodified biomass. Adsorption mechanism was investigated by FTIR. Desorption kinetics of methylene blue in six solvents: HCl (0.1 mol L(-1)), ethanol, mixtures of HCl (0.1 mol L(-1)) and ethanol with different volume ratio and a self-clean eluent: acid TiO(2) were studied in details. Results showed that desorption kinetics curve fit the two-step kinetic model, and methylene blue release process was distinctly divided into two steps: rapid and slow desorption steps. 52.2% of the methylene blue could be desorbed into TiO(2) hydrosol after 30 h desorption at the first desorption cycle, and the desorbed dye in TiO(2) hydrosol could be degrade completely under sunlight irradiation. After three desorption-photodegradation cycles, 80.0% of the absorbed dyes could be desorbed from the surface of the modified biomass. Although there was much work to do, the self-clean eluent: TiO(2) hydrosol had great potential in practical use.
authors.affiliation: Hubei Novel Reactor & Green Chemical Technology Key Laboratory, Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology, Wuhan 430074, China. yujunxia_1979@yahoo.com.cn
authors.forename: Jun-Xia
authors.initials: JX
authors.lastname: Yu
authors.forename: Ru-An
authors.initials: RA
authors.lastname: Chi
authors.forename: Xiu-Zhu
authors.initials: XZ
authors.lastname: Su
authors.forename: Zheng-Yan
authors.initials: ZY
authors.lastname: He
authors.forename: Ya-Feng
authors.initials: YF
authors.lastname: Qi
authors.forename: Yue-Fei
authors.initials: YF
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D001515:Beer; D001565:Benzoates / Q000737:chemistry*; D007220:Industrial Waste / Q000517:prevention & control; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry*; D013472:Sunlight; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015003:Yeasts / Q000737:chemistry*
chemical_list: D001565:Benzoates; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; C012019:pyromellitic dianhydride; D014025:Titanium; D008751:Methylene Blue