Occurrence, removal, and environmental risk of phthalates in wastewaters, landfill leachates, and groundwater in Poland

Abstract

Phthalates or phthalic acid esters (PAEs) are chemical compounds whose use is exceptionally widespread in everyday materials but, at the same time, have been proven to have harmful effects on living organisms. Effluents from municipal wastewater treatment plants (WWTP) and leachates from municipal solid waste (MSW) landfills are important sources of phthalates with respect to naturally occurring waters. The main aim of this research was determination, mass loads, removal rates and ecological risk assessment of eight phthalates in municipal wastewaters, landfill leachates and groundwater from Polish WWTPs and MSW landfills. Solid-phase microextraction and gas chromatography with mass spectrometry were used for the extraction and determination of analytes. Summed up concentrations of eight phthalates ranged from below LOD to 596 μg/L in influent wastewater with the highest concentration found for bis-2-ethylhexyl phthalate (DEHP) (143 μg/L). The average degree of phthalate removal varies depending on the capacity of a given treatment plant with larger treatment plants coping better than smaller ones. The highest treatment efficiency for all tested treatment plants, over 90%, was reported for dimethyl phthalate (DMP) and diethyl phthalate (DEP). Overall concentrations of phthalates in leachates ranged from below LOD to 303 μg/L while the highest maximum concentration was registered for DEHP (249 μg/L). Overall concentrations of phthalic acid esters in groundwater from upstream monitoring wells ranged from below LOD to 1.8 μg/L and from LOD to 27.9 μg/L in samples from wells downstream of MSW landfills. The obtained data shows that diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), DEHP, and diisononyl phthalate (DINP) pose a high risk for all trophic levels being considered in effluent wastewaters. In the case of groundwater high environmental risk was recorded for DBP and DEHP for all tested trophic levels. Phthalates, in concentrations that pose a high environmental risk, are present in Polish municipal after-treatment wastewater as well as in groundwater under municipal solid waste landfills.

Keywords: Environmental risk; Mass loads; Municipal solid waste landfills; Municipal wastewater treatment plants; Phthalates; Removal efficiency.