title: Biosorption of divalent Pb, Cd and Zn on aragonite and calcite mollusk shells.
abstract: The potential of using mollusk shell powder in aragonite (razor clam shells, RCS) and calcite phase (oyster shells, OS) to remove Pb(2+), Cd(2+) and Zn(2+) from contaminated water was investigated. Both biogenic sorbents displayed very high sorption capacities for the three metals except for Cd on OS. XRD, SEM and XPS results demonstrated that surface precipitation leading to crystal growth took place during sorption. Calcite OS displayed a remarkably higher sorption capacity to Pb than aragonite RCS, while the opposite was observed for Cd. However, both sorbents displayed similar sorption capacities to Zn. These could be due to the different extent of matching in crystal lattice between the metal bearing precipitate and the substrates. The initial pH of the solution, sorbent's dosage and grain size affected the removal efficiency of the heavy meals significantly, while the organic matter in mollusk shells affected the removal efficiency to a lesser extent.
authors.affiliation: Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Du
authors.forename: Fei
authors.initials: F
authors.lastname: Lian
authors.forename: Lingyan
authors.initials: L
authors.lastname: Zhu
mesh_terms: D000327:Adsorption; D000818:Animals; D002104:Cadmium / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007854:Lead / Q000737:chemistry*; D008974:Mollusca / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium; D007854:Lead; D002119:Calcium Carbonate; D015032:Zinc