title: Adsorption of valuable metals from leachates of mobile phone wastes using biopolymers and activated carbon.
abstract: In this work, chitin (CTN), chitosan (CTS) and activated carbon (AC) were used as adsorbents to recover valuable metals from leachates of mobile phone wastes. The mobile phone wastes (contactors) were collected and characterized. The valuable metals were extracted by thiourea leaching. The adsorption of valuable metals from leachates was studied according to the kinetic and equilibrium viewpoints. It was found that the contactors were composed by Au, Ni, Cu and Sn. The thiourea leaching provided extraction percentages of 68.6% for Au, 22.1% for Ni and 2.8% for Cu. Sn was not extracted. The leachate presented 17.5 mg L-1of Au, 324.9 mg L-1of Ni and 573.1 mg L-1of Cu. The adsorption was fast, being the equilibrium attained within 120 min. The adsorption of Au, Ni and Cu onto CTN and AC followed the Langmuir model, while, the adsorption of these metals onto CTS, followed the Freundlich model. Removal percentages higher than 95% were obtained for all metals, depending of the type and amount of adsorbent. It was demonstrated that the adsorption onto chitin, chitosan and activated carbon can be an alternative to recover valuable metals from leachates of mobile phone wastes.
authors.affiliation: Environmental Processes Laboratory (LAPAM), Chemical Engineering Department, Federal University of Santa Maria - UFSM, Santa Maria, RS, Brazil.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Zazycki
authors.affiliation: Environmental Processes Laboratory (LAPAM), Chemical Engineering Department, Federal University of Santa Maria - UFSM, Santa Maria, RS, Brazil.
authors.forename: Eduardo H
authors.initials: EH
authors.lastname: Tanabe
authors.affiliation: Environmental Processes Laboratory (LAPAM), Chemical Engineering Department, Federal University of Santa Maria - UFSM, Santa Maria, RS, Brazil.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Bertuol
authors.affiliation: Environmental Processes Laboratory (LAPAM), Chemical Engineering Department, Federal University of Santa Maria - UFSM, Santa Maria, RS, Brazil. Electronic address: guilherme_dotto@yahoo.com.br.
authors.forename: Guilherme L
authors.initials: GL
authors.lastname: Dotto
mesh_terms: D000327:Adsorption; D040421:Cell Phone; D002606:Charcoal / Q000737:chemistry; D002686:Chitin / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry; D059029:Electronic Waste; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000737:chemistry / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D017550:Spectroscopy, Fourier Transform Infrared; D013890:Thiourea / Q000737:chemistry; D018505:Waste Management / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D008670:Metals; D002686:Chitin; D002606:Charcoal; D048271:Chitosan; D013890:Thiourea
keywords: Adsorption; Contactors; Leachates; Mobile phones; Valuable metals