Chemodynamics, transport behaviour and treatment of phthalic acid esters in municipal landfill leachates

Abstract

Large amounts of phthalic acid esters (PAEs) are leached from plastics dumped at municipal landfills. This leachate transports PAEs either adsorbed on particulate matter or in dissolved phase. Dissolved organic macromolecules, mainly humic-like substances, enhance the solubility of PAEs. In the biochemical environments of municipal landfills short chain PAEs can be degraded by base-catalyzed hydrolysis or by microorganisms which enzymatically split the side chains. However, there is no cleavage of the aromatic ring. Long chain PAEs like di-(2-ethylhexyl) phthalate are neither degraded abiotically nor by microorganisms. Hence, these PAEs can be leached and washed out of leaky landfills into the groundwater and thus continue to be a threat to the aquatic environment. Only a combined UV radiation/ozonation treatment is capable of fully destroying PAEs.