MOBILITY OF ORGANIC PESTICIDES FROM RECYCLED CONCRETE

摘要

Concrete samples from demolition waste of a former pesticide plant in Sweden were analysed for total contents and mobility of phenoxy acids, chlorophenols and chlorocresols by standard based but modified column leaching and pH-stat tests. Compared to national Swedish guidelines, recycling of the concrete has likely to be restricted due to elevated contents of chromium and lead, as well as due to high chloride concentrations in the first leachate from column tests (at L/S 0.1). Landfilling at inert waste landfills in the EU is likely to be impossible due to leaching of phenols exceeding limit values (measured as phenol index). The larger risk stated by the reuse of this crushed and recycled concrete in situ or ex situ in groundwork constructions is probably by leaching of pesticide residues to ground- and surface waters. The compounds studied appear to be relavitely mobile at the materials own pH at 12.3 and even down to neutral pH-values. The results of this study have to be verified for the impact of the test-equipment and reproducibility at other labs, as leaching tests applied deviated from standards. Results of this study show that mobility of organic pesticides in construction and demolition wastes have to be taken into regard for decisions on environmentally sound reuse and recycling.