title: Preparation and sorption properties of materials from paper sludge.
abstract: Three materials were prepared from paper sludge (PS) using different treatment processes and their sorption abilities for phosphate and methylene blue (MB) were determined. The samples were a powder sample prepared by heating PS in air (sample C), a pellet prepared by grinding, forming and heating PS in air (sample G) and a powder prepared by physical activation of PS in flowing wet nitrogen (sample A). The three samples were heated at 600-900 degrees C for 6h. On heating at 700-800 degrees C, the organic fibers, limestone (CaCO3), kaolinite (Al2Si2O5(OH)4) and talc (Mg3Si4O10(OH)2) in the original PS were converted to amorphous CaO-Al2O3-SiO2 (CAS) and talc in sample C, while CAS was formed in sample G and activated carbon, CAS and talc was formed in sample A. On heating at 900 degrees C the CAS converted to gehlenite (Ca2Al2SiO7) and anorthite (CaAl2Si2O8). The specific surface areas (SBET) of the three samples achieved maximum values of 23, 37 and 70 m2/g upon heating at 700, 600 and 600 degrees C, respectively. The SBET value of the activated sample A was distinctly lower than usually reported for activated carbon. The samples C, G and A achieved maximum phosphate sorption capacities of 2.04, 1.38 and 1.70 mmol/g, calculated from the Langmuir model, upon heating at 700, 700 and 800 degrees C, respectively. The maximum sorption capacity for phosphate in sample C is attributed to the sorption by CAS, namely, adsorption on the alumina component and precipitation as Ca-phosphates. The MB multifunctional sorption capacity of sample A was 0.11 mmol/g. The phosphate and MB sorption rates show better correlation with a pseudo-second order model than with other models.
authors.affiliation: Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, O-okayama, Meguro, Tokyo 152-8552, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hojamberdiev
authors.forename: Y
authors.initials: Y
authors.lastname: Kameshima
authors.forename: A
authors.initials: A
authors.lastname: Nakajima
authors.forename: K
authors.initials: K
authors.lastname: Okada
authors.forename: Z
authors.initials: Z
authors.lastname: Kadirova
mesh_terms: D000327:Adsorption; D002119:Calcium Carbonate / Q000032:analysis; D002623:Chemistry Techniques, Analytical / Q000379:methods; D002627:Chemistry, Physical / Q000379:methods; D007477:Ions; D007616:Kaolin / Q000032:analysis; D008751:Methylene Blue / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010209:Paper; D010710:Phosphates / Q000737:chemistry; D011208:Powders; D012722:Sewage; D013314:Stress, Mechanical; D013627:Talc / Q000032:analysis; D013696:Temperature
chemical_list: D007477:Ions; D010710:Phosphates; D011208:Powders; D012722:Sewage; D013627:Talc; D007616:Kaolin; D002119:Calcium Carbonate; D008751:Methylene Blue