Occurrence and fate of endocrine disrupting chemicals in ASP based sewage treatment plant in Hardwar

The occurrence of emerging contaminants such as endocrine disrupting chemicals (EDCs) in our water resources is of prime concern. With this context, fate and seasonal variation of six EDCs (testosterone, T; progesterone, P; diethyl phthalate, DEP; dibutyl phthalate, DBP; propyl-paraben, PP and butyl-paraben, BP) were assessed throughout the year, i.e. in rainy, winter, spring and summer seasons in the raw, treated wastewater and activated sludge in an activated sludge process (ASP) based sewage treatment plant (STP) located in Haridwar, India. Qualitative and quantitative measurements were performed by gas chromatography-mass spectrometry (GC-MS) analysis. Results indicate that in summer, the examined STP could effectively remove 82.9% of T, 86.4% of P, 95.5% of DEP, 92.4% of DBP, 91.5% of PP, and 89.9% of BP from the wastewater. Among the EDCs considered, higher removal efficiencies were achieved for phthalates in the summer season. GC-MS analysis showed that a small fraction of EDCs was sorbed on the solid fraction of activated sludge. Scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier transformation infrared spectroscopy analysis were also performed to investigate the occurrence of EDCs in biomass samples. Results of this study also demonstrated that removal efficiency, assessed in terms of physicochemical and microbiological parameters, was maximum in summer and reached minimum in rainy season.