title: Synthesis and characterization of Fe-MCM-41 from rice husk silica by hydrothermal technique for arsenate adsorption.
abstract: Rice husk (RH) agro-waste was used as a raw material for synthesizing mesoporous molecular sieves, MCM-41. The Fe-MCM-41 was prepared by the hydrothermal technique (HT), resulting in a higher surface area and crystallinity than when prepared under ambient conditions. In addition, a hexagonal structure was clearly seen with hydrothermal technique (HT) preparation. The adsorption of arsenate by HT-Fe-MCM-41 was investigated. The factors studied affecting arsenate adsorption capacity were ferric content in MCM-41, contact time, pH of solution, and initial arsenate concentration. It was found that HT-Fe-MCM-41 at the Si/Fe mole ratio of 10 gave the highest adsorption capacity. Arsenate adsorption reached equilibrium within 4 h. The adsorption capacity of HT-Fe-MCM-41 (Si/Fe = 10) was affected by the initial pH value and the initial arsenate concentration. The adsorption capacity was highest at pH 3 and decreased thereafter with increases in the pH of solution value. The Langmuir model fit the arsenate adsorption isotherm well. The maximum adsorption capacity for arsenate was 1,111 microg g(-1).
authors.affiliation: Department of Chemical Engineering, Faculty of Engineering, Thammasat University, Pathumthani 10120, Thailand.
authors.forename: Kitirote
authors.initials: K
authors.lastname: Wantala
authors.forename: Suthipong
authors.initials: S
authors.lastname: Sthiannopkao
authors.forename: Bang-orn
authors.initials: BO
authors.lastname: Srinameb
authors.forename: Nurak
authors.initials: N
authors.lastname: Grisdanurak
authors.forename: Kyoung Woong
authors.initials: KW
authors.lastname: Kim
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000032:analysis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D008956:Models, Chemical; D012275:Oryza / Q000737:chemistry; D012822:Silicon Dioxide / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D001149:Arsenates; C509968:MCM-41; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; D007501:Iron; C025657:arsenic acid
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