title: Reduction of acidity and removal of metal ions from coal mining effluents using chitosan microspheres.
abstract: Effluents from coal mining operations are not only highly acid but also depict elevated concentrations of metals which may contaminate the environment. Due to the polybasic characteristic of chitosan, this biopolymer is capable of both neutralizing and removing iron, aluminum and copper ions from such effluents. The present study aimed at evaluating the use of chitosan microspheres for their importance in continuous systems. The microspheres were prepared by the phase inversion method. Their average diameter and morphology were determined. Water samples from decantation pool (DP) and acidic mine drainage (AMD) effluents were treated using different amounts of microspheres. The pH and concentration of Fe, Al and Cu ions were evaluated both before and after treatment of effluent samples. The results revealed that the microspheres were capable of increasing the pH of DP and AMD samples from 2.34 and 2.58, respectively, to 6.20, i.e., close to neutrality. The treatment also resulted in full removal of the metals investigated.
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis 88040-900, Santa Catarina, Brazil.
authors.forename: Rogério
authors.initials: R
authors.lastname: Laus
authors.forename: Reginaldo
authors.initials: R
authors.lastname: Geremias
authors.forename: Helder L
authors.initials: HL
authors.lastname: Vasconcelos
authors.forename: Mauro C M
authors.initials: MC
authors.lastname: Laranjeira
authors.forename: Valfredo T
authors.initials: VT
authors.lastname: Fávere
mesh_terms: D000143:Acids / Q000737:chemistry*; D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D003032:Coal Mining; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D008863:Microspheres
chemical_list: D000143:Acids; D048271:Chitosan