02819nam a2200217 a 450000100080000000500110000800800410001910000200006024501220008026001570020230000180035950000160037752020850039365000170247865300160249565300190251165300160253070000210254670000190256770000150258618605862020-01-15       2010    bl uuuu     u00u1 u    #d1 aSILVA, F. C. da  aEvaluation of bioavailability of heavy metals in urban waste in solid for extractors in Brazilh[electronic resource]  aIn: INTERNATIONAL ORBIT CONFERENCE, 7., 2010, Heraklion Crete. Organic resources in the carbon economy: proceedings. Thessaloniki, Greece: Grafimac2010  ap. 1247-1255.  aOrbit 2010.  aThe organic fraction of urban solid waste (USW) is around 60% of the total. The composting is a simple and efficient process to recycle this fraction of the USW, transforming it in organic fertilizer. The compounds of waste can contain a value assigned to aggregate economic potential of reuse of micronutrients (Cu, Ni and Zn) contained therein, in the production process, essential for plants. However, they can also contain metal contaminants (Pb, Cd, Cr) phytoavailable. For both experiments mounted a bioavailability 12 vessels were used by adding in each, 1.8 kg of each compound with different levels of metals and made 3 replicates for each treatment. Was transplanted and grown lettuce seedlings obtained prior to the planting tray. After 56 days after transplantation p seedlings were removed whole (shoot and root) measured total and the substrates analyzed for heavy metals by various extractants. After the first cut were produced new lettuce seedlings which were planted in pots where they were the first plants (first crop), proceeding similarly to the collection of plants, growth after 56 days. The results obtained by different extractants are shown in Table 1 shows that the nutrients and other metals found in the substrate of compost at different levels of maturity in composting plants in the State of São Paulo (Brazil), where is cultivated lettuce in two successive cycles. Notes to the range of variation of heavy metal compounds formed in the substrate, before and after cultivation of lettuce. Extractors Mehlich 1 and DTPA for Zn and the last to lead and most methods for Cr were not able to observe the removal of metals in the substrate by cultivation. Values in quantity (mg / kg) in the compound and the percentage of regression coefficient (R2,%) with fitoacumulated heavy metals, there is the distinct values for the extractants. (Table 1). The total contents of metals present in the compounds of urban garbage were within acceptable standards exist in Brazil, mainly in European countries, as the acceptable values of metals contained therein.  aHeavy metals  aLixo urbano  aMetais pesados  aUrban waste1 aCHITOLINA, J. C.1 aBARIONI, L. G.1 aCASTRO, A.