Removal of bis(2-ethylhexyl) phthalate at a sewage treatment plant.
Bis(2-ethylhexyl) phthalate (DEHP) concentrations were measured at different stages in a full-scale sewage treatment plant (STP) and mass balances were calculated. The DEHP load to treatment process coming from the sewer system and the internal load comprising returned supernatants and filtrate from sludge treatment and excess secondary sludge were at the same level. The DEHP removal efficiency from the water phase at the STP was on average 94% of sewage DEHP, the main removal process being sorption to primary and secondary sludges. On average 29% of DEHP was calculated to be removed in the biological nitrifying-denitrifying activated sludge process, which was much less than expected from laboratory biodegradation studies described in literature. Monoethylhexyl phthalate, the primary biotransformation product of DEHP, was not detected at any treatment stage. Approximately 32% of DEHP in sewage was removed during anaerobic digestion of the sludge, while 32% remained in the digested and dewatered sludge.
Marttinen
Sanna K
SK
Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FIN-40014, Finland. sanna.marttinen@jyu.fi
Kettunen
Riitta H
RH
Sormunen
Kai M
KM
Rintala
Jukka A
JA
D004051:Diethylhexyl Phthalate / Q000302:isolation & purification*; D004784:Environmental Monitoring; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D012722:Sewage; D014874:Water Pollutants, Chemical; D004051:Diethylhexyl Phthalate