Alina LAŢO, Isidora RADULOV, Adina BERBECEA, Karol LAŢO, Florin CRISTA None
In sewage sludge the metals are finding in different forms, in function of chemical properties of sewage sludge and the chemistry of the metal. It was calculate the transfer factor of some metals, from soil in maize grains after sewage sludge distribution on land. The analyzed metals are: copper, iron and lead. It is known that only a part of the metals content from soil is transferred in plant, in our case being the maize grains. The analyses were made on soil samples and on maize grains. We establish the metals transfer factor using a standard formula. It was choose these three metals because their concentration in sewage sludge was higher comparative to the other metals. The experiment was done on maize hybrid: Lovrin 400 and the soil type is cambic chernozem, poorly glazed, which is characteristic for the USAMVB`s Research Station from Timisoara. The sewage sludge was distributed on land only one time, in different doses: 0, 20, 40 and 60 t ha-1 and we observe the remaining effect on soil and plants. The content in metals from soil was determinate in aqua regia extract and values were established to an atomic absorption spectrophotometer at different wave lengths: Fe at 510 nm, Pb at 217 nm, Cu at 470 nm).The plant samples (maize grains) were burned and after that were treated with HCl 0.1 N, and the content in metals was established as in soil case, using the same method. It was observed in soil a high content of iron, but in case of the other studied elements, their concentration is finding in normal limits. The highest values of transfer factor were determinate in case of iron, than copper and the lowest values were established for lead. After the analyses that were made, the maize grains can be used as food for animals and the fodder is not polluted with toxic metals. In the last years, in each city, after the waste waters treatment result high quantities of sludge which might be used in agriculture but it must be respected some conditions, such as the maximum dose admitted to be distribute on land in order to not produce the pollution of soil, plants, waters and food
metals, soil, plant, sewage sludge
Presentation: oral