Endocrine disrupting compounds: A comparison of removal between conventional activated sludge and membrane bioreactors

The removal of endocrine disrupting compounds (EDCs) was investigated in a conventional activated sludge plant connected with a tertiary treatment (CAS-TT) and two membrane bioreactor pilot plants installed with flat sheet (MBR-FS) and hollow fibre (MBR-HF) modules. Chemical compounds such as alkylphenols (4OP and 4tOP), nonylphenols (NP), bisphenol A (BPA), phthalates (DMP, DEP, DBP, BBP, BEHR and DOP) and estrogens (E1 and EE2) were determined in dissolved wastewater by employing stir bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry. Samples were taken during three months from the outlet of the primary settling tank (PS). the tertiary treatment and the flat sheet and hollow fibre modules. All the target compounds were detected in the effluent of the PS during the monitored period except DMP, 4OP, DOP and EE2. The MBR modules were more efficient in the removal of DEP, DBP and BBP than CAS-TT, whereas CAS-TT was more efficient in the removal of BEHP. For 4tOP and BPA the removal efficiency found was very similar when CAS-TT or MBR treatments were applied. Only slight differences were detected comparing both MBR modules. MBR-HF seemed to be adequate for DBP and NP removal, while MBR-FS was better for DEP and BBP removal. (C) 2011 Elsevier B.V. All rights reserved.