Dissolution of heavy metals from spent batteries under waste landfill conditions

摘要

A large proportion of the spent batteries are ultimately deposited in waste landfill sites amongst other domestic wastes. These batteries will then constitute a potential source of metals such as zinc, manganese, nickel, iron, cadmium, lead, mercury and chromium, which might contaminate the solution leaving the sites (leachate). The present work describes the dissolution of metals containing in spent batteries both with the naturally generated landfill leachate (pH=8.1) and with the acidified one in intervals ranging from pH 4.7 to 7. The influence of time (2,3,4,6,12,20 and 24 hours), temperature (30,35,40 and 45℃) and solid-liquid ratio 1:2 on the leaching of metals contained in the batteries have been studied. The landfill leachate was collected in the waste landfill of Gramacho-RJ-Brazil. The results showed that some of the metals present in the batteries can be dissolved in concentrations above the legal allowed limit. The domestic batteries dumped in urban waste landfills seems, therefore, to pose a health hazard and should be selectively disposed of.