title: Removal of copper ions from aqueous solution by adlai shell (Coix lacryma-jobi L.) adsorbents.
abstract: Adlai shell (Coix lacryma-jobi L.) adsorbents (ASA) were used to remove copper ions from aqueous solutions under batch conditions. The effect of physical and chemical modification of ASA on Cu(II) removal was evaluated. Results showed that the high coefficients of determination for the pseudo-second order (R(2) > 0.9999) and for the intraparticle diffusion (R(2) > 0.9843) equations indicate that the rate-determining step is a combination of pore diffusion and chemisorption at low Cu(II) concentration and boundary layer, pore diffusion and chemisorption at high Cu(II) concentration. At 298K and 100 mg L(-1) Cu(II), the computed qe and k2 values were 17.2 mg g(-1) and 0.012 g mg(-1) min(-1), respectively. The Freundlich model (R(2) > 0.9636) adequately describes the experimental data indicating heterogeneous adsorption. Overall, the results of the study demonstrate the potential of adlai shell adsorbents for the removal of heavy metals from aqueous solutions.
authors.affiliation: Department of Chemical Engineering, University of the Philippines, 1101 Diliman, Quezon City, Philippines.
authors.forename: Mark Daniel G
authors.initials: MD
authors.lastname: de Luna
authors.affiliation: Philippine Center for Postharvest Development and Mechanization, Department of Agriculture, Nueva Ecija, Philippines; Environmental Engineering Program, National Graduate School of Engineering, University of the Philippines, 1101 Diliman, Quezon City, Philippines.
authors.forename: Edgar D
authors.initials: ED
authors.lastname: Flores
authors.affiliation: Environmental Engineering Program, National Graduate School of Engineering, University of the Philippines, 1101 Diliman, Quezon City, Philippines.
authors.forename: Marie Chela B
authors.initials: MC
authors.lastname: Cenia
authors.affiliation: Department of Environmental Resources Management, Chia Nan University of Pharmacy and Science, Tainan 717, Taiwan. Electronic address: mmclu@mail.cnu.edu.tw.
authors.forename: Ming-Chun
authors.initials: MC
authors.lastname: Lu
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D031742:Coix / Q000737:chemistry*; D003300:Copper / Q000737:chemistry / Q000302:isolation & purification*; D007220:Industrial Waste / Q000517:prevention & control; D007477:Ions; D010936:Plant Extracts / Q000737:chemistry; D012639:Seeds / Q000737:chemistry*; D012996:Solutions; D014462:Ultrafiltration / Q000379:methods; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D007220:Industrial Waste; D007477:Ions; D010936:Plant Extracts; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; D003300:Copper
keywords: Adlai shell; Adsorption; Heavy metal wastewater; Isotherm; Kinetics