[en] The rapid stackingof electrical and electronic equipment in disuse throughout the world and the threat that this entails makes it necessary to search for new sustainable management and treatment systems that allow the recovery and reuse of the materials utilized in the manufactur ing process . An alternative treatment is the method of bioleaching, bioextracti on or biohydrometallurgy that are used to extract valuable metals from these residues through oxidation - reduction processes favored by the action of microorganisms. The main objective of this work is to study the sustainable recovery or bioleaching of copp er from the printed circuit boards (PCB) of disused mobile phones. The first step was the collection of mobile phones from which the printed circuit boards were extracted . After the grinding and shredding of the PCBs, a crushed sample of particle size smal ler than 0.75 mm and visually somewhat heterogeneous was obtained. Some of PCBs that were not grinded were treated with a 10 M NaOH solution , to eliminate the epoxy insulating coating that protected the lower layers of copper. The total amount of metals in the crushed sample was determined by acid digestion with aqua regia assisted by microwaves. The most abundant element was Cu, whose total average content in one gram sample was 435 ± 54 mg . Other abundant elements in the p ulverized sample were Sn (32.9 ± 3.7 mg/g), Al (19.69 ± 0.67 mg /g), Fe (12.56 ± 0.23 mg /g) and Ni (11.39 ± 1.05 mg /g). ). A commercial strain of the bacterium Acidithiobacillus ferrooxidans was purchased , activated and inoculated in a specific culture medium with a content of 9 g Fe 2 + /L. , S imilar amounts of the c ru shed sample and the not grinded PCB piece were introduced in one inoculated solution . It was concluded that the bacterial oxidation activity in the medium with the not grinded sample was higher than in the pulverized sample. This fact was attributed to the "cleaner" solution with the PCB piece, in comparison with the muddy liquid of the crushed sample, which also contained the green epoxy - 2018 iii resin . It was also concluded that once the Fe 3 + oxidant was originared , the cont act between the oxidant and the metals contained in the grinded sample wa s better than in the PCB piece , so copper extraction yields were higher in the former case (78.26% dust). and 67.96% piece ). Although the extraction of Cu was 15.1% higher in the crus hed sample experiment , it was concluded that it was operationally more recommendable to proceed with bioextraction using the entire PCBs or their pieces as long as the epoxy cover is previously removed . The PCB could be easily taken out from the medium and washed properly. In the case of dust, the residual sample remained completely mixed with the microorganisms and all the extracted metals, which made it difficult to separate the components. This preliminary work show that bioleaching al lows the efficient extraction of copper from the PCBs of disused mobile phones . A lthough there are still many aspects to be investigated for this technological alternative to be implemented at large scale, there is no doubt that the b iotechnological innova tions applied to the sustainable treatment of electronic wastes will be in a relevant position in the near future.

[eu] Erabiltzeari utzi egin zaien tresna elektriko eta elektronikoen metaketa arina eta honek dakarren arriskua, esparru honen inguruko kudeaketa eta garapen iraunkorrerako tratamenduen sistema berrien ikerketa ezinbestekoa da, tresna hauen manufakturazio prozesuan erabilitako materialak berreskuratzeko eta berrerabiltzeko asmoz. Biolixibiazioa, bioerauzketa edota biohidrometalurgia izeneko tratamendu metodo alternatiboak hondakinen baliozko metalak erauzteko balio du, eta horretarako oxidazio-erredukzio prozesuez eta mikroorganismoen akzioen laguntzaz baliatzen da. Lan honen helburu nagusia, erabilgarriak ez diren telefono mugikorren plaka baseetan (PCB) dagoen kobrea berreskuratzean datza, garapen jasangarrian edo biolixibiazioan oinarrituz. Horretarako, lehenik eta behin, telefono mugikorren bilketari ekin zitzaion eta hauen plaka baseak atera ziren. Plaken birrinketa eta ehoketaren ostean, 0.75 mm baino txikiagoko hautsa eta begi bistan heterogeneoa zen lagina eskuratu zen. Hauetako zenbait plaka ez ziren txikitu eta NaOH 10M disoluzioarekin tratatu ziren, kobrearen geruza estaltzen zuen epoxy material isolatzailea ezabatzeko. Hautsezko laginean dauden metalen kantitate totala kuantifikatzeko, mikrouhinez lagundutako digestio azidoa burutu zen aqua regia erabiliz. Gehiengo elementua Cu izan zen, bere batezbesteko edukia 435±54 mg/g zelarik. Beste gehiengo elementuak Sn (32.9±3.7 mg/g), Al (19.69±0.67 mg/g), Fe (12.56±0.23 mg/g) eta Ni (11.39±1.05 mg/g) izan ziren. Acidithiobacillus ferrooxidans bakteriaren andui bat erosieta 9 g Fe2+/L –ko edukia zuen hazkuntza espezifikoko medioan aktibatu eta inokulatu zen. Sistema inokulatuan, epoxy-rik gabeko plakaren eta hautsezko lagin aren pareko kantitateak sartu egin ziren. O xidazio bakterianoaren aktibitatea plakare n disoluzioan , hauts ezko lagin arenean baino handiago zela ondorioztatu zen. Horren zergatia medioan dago; hau da , plaka z uen disoluzioa " askoz garbiago" zegoen hautsezko disoluzioa baino. Azken horr etan, prozesuaren bukaeran disoluzioa oso nahasia eta konplexua zen biomasa gara zedin. Baina, b ehin Fe 3+ oxidatzailea eratuta, elementu ho rr en eta hauts ezko laginaren m etalen arteko kontaktua plakan baino hobeagoa z ela ondorioztatu zen ; beraz, kobrearen erauzketaren errendimendua altuagoak izan ziren lehenengo kasuan (78.26% hautsa eta 67.96% plaka). Na h iz eta hauts ezko lagin ean kobrearen erauzketa - portzentaia %15.1 handiagoa izan zen , plaka osoak (aldez aurretik epoxy estaldura kenduta) erabiltzea gomendagarriagoa zela ondorioztatu zen bioe rauzketaren alde pratikotik ikusita . Hots, plaka tratatu ostean , oso erraz atera zen disoluziotik eta egoki garbitu zen. . Hautsa ren kasuan berriz, hondakin lagina medioan nahasita geratzen zen mikroorganismo eta erauzitako metalekin batera. Hasierako lan honetan, frogatu izan da nola biolixibizazioaren bitartez kobrea erauzi daitekeen erabiltzen ez diren sakelako mugikorren PCB - eng andik modu eraginkor batean, baina, oraindik hainbat alderdi geratzen dira ikertzeko alternatiba hau eskala handi batean ezarri ahal izateko. Ez dago zalantzarik, hondakin elektronikoen tratamendu jasangarrietan berrikuntza biotekonologikoek legu garrantzi tsu bat okupatuko dutela.