ASSESSMENT AND MANAGEMENT OF HEAVY METAL CONTAMINATION OF AGRICULTURAL SOILS IN LARISSA, GREECE, BY USING ENVIRONMENTALLY FRIENDLY MATERIALS

The contamination of agricultural soils by heavy metals has aroused considerable apprehension worldwide due to their toxicity and persistence. In this study, the contamination with cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), chromium (Cr) and Zinc (Zn) in agricultural soils from two regions of Larissa (first region: agricultural soils with application of sewage sludge, second region: agricultural soils near large motorways) was assessed by collecting soil samples as well as by using appropriate contamination indices. The soil sample with the highest metal contamination, was used in pot experiment. The purpose of the experiment was to evaluate the effectiveness of treatment with a mixure of 50% manure and 50% attapulgite at three different levels (0%, 3% and 4% mix of manure - attapulgite / Kg soil) to reduce the availability of the pollutants to Quinoa (Chenopodium) plants. The agricultural soil samples were analyzed for their physicochemical properties and for “pseudo-total’’ heavy metals content after their extraction with boiling Aqua Regia and by using the atomic absorption spectrophotometer. The level of soil pollution was assessed by using Contamination Factor (CF) and Pollution Load Index (PLI). According to the PLI results, the agricultural soils both of two study regions of Larisa, was strongly polluted. Particularly, the CF results revealed that the first study region was very high contaminated with Cr and the second study region was significant and very high contaminated with Ni and Cr, respectively. The results of the pot experiment indicated that, the addition of mixure of manure and attapulgite reduces the uptake of metal pollutants by plants, confirming the possibility of using this mixture in amendment treatments of metal-contaminated soils.