Pilot Study on Treatment of Wastewater from an Ethylene Plant with Membrane Bioreactor Technology

Jian-Jun Qin*, 1, Maung Htun Oo1, Guihe Dutková1, Eberhard Tao, Kiran Arun Kekre1, Bryan Cashion2, Robert Wenta3
1 Centre for Advanced Water Technology, PUB Consultants Pte Ltd, 80/82 Toh Guan Road East, #C4-03, Singapore 608575
2 ExxonMobil Chemical Company (retired), Baytown, TX, USA
3 Siemens Water Technologies Corp., 301 West Military Road, Rothschild, WI 54474, USA

© 2008 Qin et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Centre for Advanced Water Technology, PUB Consultants Pte Ltd, 80/82 Toh Guan Road East, #C4-03, Singapore 608575; Tel: +65-63262914; Fax: +65-63262929; E-mail:


Pilot studies were conducted with an anoxic/aerobic concept membrane bioreactor (MBR) technology and a hollow fiber Petro® MBR system with capacity of 12 m3/d was operated continuously (24-hour) during the study. Trials on different membrane fluxes were conducted to obtain the sustainable flux while mixed liquor suspended solid (MLSS) was maintained at 9-11 g/L. The results of the MBR pilot trials showed that no obvious fouling of the membrane was found when the plant was operated at the flux of 12 L /m2/h (LMH) over 3 months and 15 LMH over one month during the pilot study. Design guidelines such as hydraulic retention time (HRT), sludge retention time (SRT), anoxic and aeration volume ratio, re-circulation flow rate and air scouring were obtained for a full-scale plant. It was concluded that treatment of wastewater from an ethylene plant without addition of any chemicals using MBR technology is feasible. The product quality consistently met the requirement for discharge and was suitable for the feed of further reverse osmosis (RO) post-treatment.

Keywords: Membrane bioreactor, ethylene wastewater, COD removal, nitrification, wastewater treatment and reuse.