OCCURRENCE AND FATE OF ARTIFICIAL SWEETENERS AND PERFLUORINATED COMPOUNDS IN A WASTEWATER RECLAMATION PLANT IN SINGAPORE

Abstract

RAPID ECONOMIC DEVELOPMENT AND CHANGE IN LIFE STYLES HAVE LED TO CONTINUOUS PRODUCTION AND RELEASE OF EOCS INTO WWTPS. IN THIS STUDY, THE OCCURRENCES, FATES AND BEHAVIORS OF ASS AND PFCS IN WWTPS WERE INVESTIGATED BY MONITORING THE DISSOLVED AND SUSPENDED SOLID PHASE CONCENTRATIONS IN WASTEWATER SAMPLES COLLECTED IN 9 MAJOR TREATMENT STAGES IN A WRP IN SINGAPORE. ALL THE TARGETED ASS (ACE, CYC, SAC AND SUC) AND PFCS (PFBA, PFOA, PFNA, PFDA, PFHXS, PFOS, N-ETFOSAA AND FOSAA) WERE DETECTED IN BOTH PHASES. THE WRP ONLY PARTIALLY REMOVED THESE EOCS BY ~84% FOR ASS AND <43% FOR PFCS. SORPTION ON ACTIVATED SLUDGE WAS PROPOSED AS ONE OF THE MAJOR MECHANISMS TO REMOVE THE ANALYTES FROM EFFLUENT DISCHARGE IN THE WRP. THEREFORE, CORRESPONDING BENCH-SCALE SORPTION EXPERIMENTS WERE CONDUCTED TO CONFIRM THE SORPTION AFFINITIES OF SELECTED RECALCITRANT ASS AND PFCS ON ACTIVATED SLUDGE USING DIFFERENT PREPARATION METHODS FOR ADSORBENTS.