Fate and Ecological Risk of Phthalate Esters in Microplastics of Wastewater in the Wastewater Treatment Plant

Chemicals known as phthalate acid esters, which are present in many products we use every day, were identified as priority pollutants that have negative effects on living things. A source of phthalate acid esters discharged into receiving waterways and the environment is wastewater treatment plant effluent. This study measured the content of phthalate acid esters in wastewater’s liquid portion and microplastics throughout the wastewater treatment process, as well as evaluating the ecological risk of phthalate acid esters. The highest removal efficiency in wastewater, as well as microplastics of wastewater during the treatment process, was found for diethyl phthalate with 82.35% and 94% efficiency, respectively. The obtained data suggest that di-n-butyl phthalate and benzyl butyl phthalate in wastewater effluent have a high environmental risk at all three trophic levels (fish, invertebrates, and algae/cyanobacteria); the risk quotient value of di-n-butyl phthalate for algae/cyanobacteria was over 1000. Consequently, the health of fish and other aquatic life, as well as the local population, may be threatened by wastewater effluent discharged into receiving river (the Karun River).