ROLE OF MEADOW STRIPS FOR MIGRATION OF DISSOLVED ORGANIC-COMPOUNDS AND HEAVY-METALS WITH GROUNDWATER

The migration of nitrates, phosphates and dissolved organic compounds (DOC) in groundwater from fields through meadows to small ponds was an alysed. The migration of humic substances, polysugars and polyamides w as emphasized. The role of DOC in transporting heavy metals (Cd, Cu, P b, Zn) was also estimated. When groundwater from a field was passing u nder a meadow, a decrease in humic substances and an increase in polya mides and polysugar concentrations were observed. Simultaneously, inor ganic forms of heavy metals decreased, while forms bound to DOC increa sed. Thus, a strip of meadow surrounding an aquatic system, can influe nce heavy metal migration with groundwater by its impact on DOC. Moreo ver, it was found that small mid-field ponds accumulate DOC to a large extent. The concentration of humic substances amounted on average to 34.0 mg l-1 and to 8.2 mg l-1 for polyamides and polysugars, respectiv ely. In such ponds, the concentration of heavy metals, especially Cu a nd Zn in forms bound to DOC, also increased.