Sorption and biodegradation of artificial sweeteners in activated sludge processes.
There is limited information on the occurrence and removal of artificial sweeteners (ASs) in biological wastewater treatment plants, and in particular, the contribution of sorption and biodegradation to their removal. This study investigated the fate of ASs in both the aqueous and solid phases in a water reclamation plant (WRP). All the four targeted ASs, i.e. acesulfame (ACE), sucralose (SUC), cyclamate (CYC) and saccharine (SAC), were detected in both the aqueous and solid phases of raw influent and primary effluent samples. The concentrations of CYC and SAC in secondary effluent or MBR permeate were below their method detection limits. ACE and SUC were persistent throughout the WRP, whereas CYC and SAC were completely removed in biological treatment (>99%). Experimental results showed that sorption played a minor role in the elimination of the ASs due to the relatively low sorption coefficients (Kd), where Kd<500L/kg. In particular, the poor removal of ACE and SUC in the WRP may be attributed to their physiochemical properties (i.e. logKow<0 or logD<3.2) and chemical structures containing strong withdrawing electron functional groups in heterocyclic rings (i.e. chloride and sulfonate).
NUS Environmental Research Institute, National University of Singapore, T-Lab Building, #02-01, 5A Engineering Drive 1, Singapore 117411, Singapore. Electronic address: hantn04779@yahoo.com.
Ngoc Han
NH
Tran
Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore.
Jie
J
Gan
Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore; PUB, WaterHub, 82 Toh Guan Road East, Singapore.
Viet Tung
VT
Nguyen
Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore.
Huiting
H
Chen
Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore.
Luhua
L
You
PUB, WaterHub, 82 Toh Guan Road East, Singapore.
Ankur
A
Duarah
PUB, WaterHub, 82 Toh Guan Road East, Singapore.
Lifeng
L
Zhang
Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore. Electronic address: ceeginyh@nus.edu.sg.
Karina Yew-Hoong
KY
Gin
D000327:Adsorption; D001673:Biodegradation, Environmental; D003494:Cyclamates / Q000737:chemistry / Q000378:metabolism*; D012439:Saccharin / Q000737:chemistry / Q000378:metabolism*; D012722:Sewage / Q000737:chemistry*; D013395:Sucrose / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D013549:Sweetening Agents / Q000737:chemistry / Q000378:metabolism*; D013843:Thiazines / Q000737:chemistry / Q000378:metabolism*
D003494:Cyclamates; D012722:Sewage; D013549:Sweetening Agents; D013843:Thiazines; D013395:Sucrose; C026285:trichlorosucrose; D012439:Saccharin; C006362:acetosulfame
Activated sludge process; Artificial sweeteners (ASs); Biodegradation; Sorption; Wastewater treatment plants (WWTPs)