OCCURRENCE AND ENVIRONMENTAL FATE OF PHARMACEUTICALS, PERSONAL CARE PRODUCTS (PPCPS) AND ENDOCRINE DISRUPTING CHEMICALS (EDCS) IN A TROPICAL URBAN CATCHMENT

Abstract

This thesis focuses on the distribution and attenuation behavior of selected PPCPs/EDCs in an urban catchment of Singapore. The spatial and temporal patterns of the target analytes (including pharmaceuticals, hormones, plasticizers, insect repellents, disinfectants and UV filters) in surface waters during a 16-month field survey were evaluated and correlated to environmental factors. The information obtained contributes to their risk assessment in urban aquatic environments. The multi-phase distribution of PPCPs/EDCs was further examined in catchment water and bottom sediments. The relationship between the field-based partitioning coefficients and Log Kow for these analytes was examined. The characteristics of sorption, biodegradation and photolysis of 7 most frequently detected PPCPs in the water environment were also investigated in controlled laboratory experiments. The study revealed the impacts of sorption history, environmental matrices and hysteresis in the sorption-desorption process as well as the degradation kinetics in both surface water and sediments.