EPR IN THE ENVIRONMENTAL-CONTROL - COPPER-COMPLEXES AND FREE-RADICALSIN SOIL AND MUNICIPAL SOLID-WASTE COMPOST

Quantitative EPR technique was applied to examine Cu(II) complexes and free radicals in soil and municipal solid waste composts. Production and stabilization of free radicals in humic and humic-like substances depend on transition metal containing red-ox systems in soil. Terminat ion of the reaction pathways yields relatively stable semiquinone free radicals in the polyphenol and melanoidin matrices. EPR investigation s of municipal solid waste composts in different stages of their matur ity show distinct correlation between free radical concentration and m icrobiological activity. Copper(II) sorption by living microorganisms and formation of the copper(II) complexes by humic substances in soils (Cambisols and Luvisols) result in decrease of the concentration of t he semiquinone radicals. The Cu(II) complexes formed by various natura l humic and humic-like substances produced in the composts were charac terized on the basis of EPR measurements. The process of solubilizatio n of inorganic copper compounds in soil and composts, and free radical activity in soil and composts can be characterized using EPR techniqu e as the monitoring method.