Review Membrane bioreactor: Applications and limitations in treating high strength industrial wastewater Noor Sabrina Ahmad Mutamim a,c , Zainura Zainon Noor a,⇑ , Mohd Ariffin Abu Hassan a , Adhi Yuniarto a , Gustaf Olsson b a Department of Chemical Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia b Department of Industrial Electrical Engineering and Automation (IEA), Lund University, Box 118, SE-22100 Lund, Sweden c Department of Chemical Engineering, Faculty of Chemical Engineering and Natural Resources, Universiti Malaysia Pahang, Leburaya Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia highlights  The state of the art of membrane bioreactor (MBR) technology for application to high strength wastewater is reviewed.  Treatment in MBRs can be very effective.  The major impediment to more widespread application is membrane fouling.  Mitigation of fouling can use physical or chemical methods, or combination of both. article info Article history: Received 3 May 2012 Received in revised form 19 February 2013 Accepted 27 February 2013 Available online 25 March 2013 Keywords: Industrial wastewater Membrane bioreactor Biodegradability Fouling abstract This paper reviewed the application of membrane bioreactor in treating high strength industrial waste- water by analysing operational parameters, limitations and mitigations of MBR for industrial wastewater. High strength industrial wastewater is difficult to classify but by its characteristics can be predicted using biodegradability criteria (BOD 5 /COD). Several factors need to be taken into consideration to find suitable operating parameters such as hydraulic retention time (HRT), solid retention time (SRT), mix liquor sus- pended solid (MLSS), food to microorganism (F/M), transmembrane pressure (TMP) and Flux (J) to obtain good quality effluent and reduce the fouling effect. Fouling factors by membrane, biomass and MBR oper- ation need to be taken seriously because they are the major problems affecting the performance of the MBR and quality of the effluent. There are specific methods to reduce and clean the clogging membrane depending on the level of severity of the fouling. The mitigation covers physical cleaning such as mem- brane relaxing, backwashing, a combination of both and chemical cleaning which is used for irreversible fouling. In some cases, modification of MBR is needed to improve the performance and to achieve high quality of effluent. Ó 2013 Elsevier B.V. All rights reserved. Contents 1. Introduction ......................................................................................................... 110 2. High strength industrial wastewater behaviour ............................................................................. 110 3. A general MBR configuration............................................................................................ 111 3.1. Membrane behaviour ............................................................................................ 112 1385-8947/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.cej.2013.02.131 Abbreviations: BAP, biomass-associated products; BOD 5 , biological oxygen demand; CAS, conventional activated sludge; EMBR, extractive MBR; EPS, extra cellular polymeric substance; Floc, suspended solid particle of the mixed liquor; Flux, volumetric flow rate per unit membrane area (LMH or m/d); F/M, food per microorganism; FS, flat sheet; HF, hollow fibre; HRT, hydraulic retention time (the time taken for the liquid phase to pass through a tank); iMBR, immersed MBR; MABR, membrane aerated biofilm reactor; MBR, membrane bioreactor; MF, microfiltration; Mixed liquor, the material formed in the bioreactor, containing biomass and other solids; MLSS, mixed liquor suspended solids; NF, nanofiltration; PAC, powdered activated carbon; Permeability, flux per unit TMP; PE, polyethylene; PES, polyethylsulphone; PP, polypropyle; PVDF, polyvinylidene; sMBR, sidestream MBR; SMBR, submerged MBR; SMP, soluble microbial product; SND, simultaneous nitrification denitrification; SRT, solids retention time: the time taken for the solid (particulate) phase to pass through a tank; TKN, total Kjeldahl nitrogen; TMP, transmembrane pressure (Pa); TOC, total organic compound; TSS, total suspended solid (mg/L); UAP, substrate utilisation-associated products; UF, ultrafiltration. ⇑ Corresponding author. Tel.: +60 7 5535534; fax: +60 7 5581463. E-mail address: zainurazn@utm.my (Z.Z. Noor). Chemical Engineering Journal 225 (2013) 109–119 Contents lists available at SciVerse ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej