title: Biosorption of cadmium by CO(2)-fixing microalga Scenedesmus obliquus CNW-N.
abstract: An efficient CO(2)-fixing indigenous microalga Scenedesmus obliquus CNW-N was used as the biosorbent to remove cadmium from aqueous solution. The microalga was grown with continuous feeding of 2.5% CO(2), achieving a maximum CO(2) consumption rate of 495 mg/l/d and a biomass production of 2.56 g/l. Cadmium (Cd) biosorption by S. obliquus CNW-N was optimal at pH 6.0 and 30 °C. For an initial cadmium concentration of 50mg/l, the biosorption capacity tended to decrease with an increase in biosorbent, while the cadmium removal efficiency was nearly 100% when the biosorbent loading was higher than 0.6g. The biosorption kinetics followed the pseudo-second order adsorption model. The adsorption equilibrium obeys Langmuir isotherm with an estimated maximum capacity of 68.6 mg/g and a saturation coefficient of 0.101 l/mg. The cadmium-loaded microalgal biomass could be regenerated preferably with 0.05 M CaCl(2), as the regenerated biosorbent retained good adsorption capability after five consecutive adsorption/desorption cycles.
authors.affiliation: Microalgae Biotechnology and Bioengineering Laboratory, University Center for Biosciences and Biotechnology, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Chen
authors.forename: Hao-Wei
authors.initials: HW
authors.lastname: Chang
authors.forename: Pei-Chun
authors.initials: PC
authors.lastname: Kao
authors.forename: Jian-Liang
authors.initials: JL
authors.lastname: Pan
authors.forename: Jo-Shu
authors.initials: JS
authors.lastname: Chang
mesh_terms: D000327:Adsorption; D018533:Biomass; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D002104:Cadmium / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D058086:Microalgae / Q000378:metabolism*; D010777:Photochemistry / Q000379:methods; D044444:Scenedesmus / Q000378:metabolism*; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium; D002245:Carbon Dioxide