Determination of heavy metals in Eucalyptus grandis, manured with biosolid, by neutrons activation analysis

The biosolid is a mud resulting from the biological treatment of wasted liquids. It is considered as a profitable alternative and important to minimize the environmental impact generated by the sewage thrown in the sanitary lands. The utilization of biosolid in forest cultures, as the Eucalyptus grandis, is of great economic and scientific interest, because it promotes not only the use of sewage residues, but also a fertilization prices reduction. The objective of this work was to detect the presence of heavy metals in Eucalyptus grandis sample fertilized with different quantities of biosolid. For the experiment, we used the plantation of Estacao Experimental de Ciencias Florestais of Itatinga, linked to ESALQ of Universidade de Sao Paulo - USP. The eucalyptus were planted in March of 1998 and collect with five years old. The used biosolid was produced by ETE of Barueri - SP, classified as kind B. The samples were prepared in Universidade Estadual Paulista of Itapeva. For the determination of heavy metals presence in eucalyptus samples, an analysis technique by neutronic activation (NAA) was used followed by gamma rays spectroscopy. The samples were irradiated in the Nuclear Reactor IEA-R1 of IPEN-SP, followed by the measure of induced gamma rays activity, using a Detector HPGe. The presence, mainly of Br, Mn, Na and K, was detected in all analyzed samples. (author)