title: Bioleaching of metals from printed circuit boards supported with surfactant-producing bacteria.
abstract: This study has evaluated the possibility of bioleaching zinc, copper, lead, nickel, cadmium and chromium from printed circuit boards by applying a culture of sulphur-oxidising bacteria and a mixed culture of biosurfactant-producing bacteria and sulphur-oxidising bacteria. It was revealed that zinc was removed effectively both in a traditional solution acidified by a way of microbial oxidation of sulphur and when using a microbial culture containing sulphur-oxidising and biosurfactant-producing bacteria. The average process efficiency was 48% for Zn dissolution. Cadmium removal was similar in both media, with a highest metal release of 93%. For nickel and copper, a better effect was obtained in the acidic medium, with a process effectiveness of 48.5% and 53%, respectively. Chromium was the only metal that was removed more effectively in the bioleaching medium containing both sulphur-oxidising and biosurfactant-producing bacteria. Lead was removed from the printed circuit boards with very low effectiveness (below 0.5%). Aerating the culture medium with compressed air increased the release of all metals in the medium with sulphur and biosurfactant, and of Ni, Cu, Zn and Cr in the acidic medium. Increasing the temperature of the medium (to 37°C) had a more significant impact in the acidic environment than in the neutral environment.
authors.affiliation: Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw, Poland. Electronic address: ewa.karwowska@is.pw.edu.pl.
authors.forename: Ewa
authors.initials: E
authors.lastname: Karwowska
authors.affiliation: Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Andrzejewska-Morzuch
authors.affiliation: Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Łebkowska
authors.affiliation: Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw, Poland. Electronic address: agnieszka.tabernacka@is.pw.edu.pl.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Tabernacka
authors.affiliation: Warsaw University of Technology, Faculty of Environmental Engineering, Nowowiejska 20, 00-653 Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Wojtkowska
authors.affiliation: Warsaw University of Technology, Faculty of Environmental Engineering, Nowowiejska 20, 00-653 Warsaw, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Telepko
authors.affiliation: Warsaw University of Technology, Faculty of Environmental Engineering, Nowowiejska 20, 00-653 Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Konarzewska
mesh_terms: D042763:Acidithiobacillus / Q000378:metabolism*; D001409:Bacillus cereus / Q000378:metabolism*; D001412:Bacillus subtilis / Q000378:metabolism*; D059029:Electronic Waste; D019216:Metals, Heavy / Q000302:isolation & purification* / Q000378:metabolism; D059027:Recycling
chemical_list: D019216:Metals, Heavy
keywords: Bioleaching; Biosurfactant producing bacteria; Heavy metal; Printed circuit boards