Send Orders for Reprints to reprints@benthamscience.net Recent Patents on Engineering, 2014, 8, 000-000 1 1872-2121/14 $100.00+.00 © 2014 Bentham Science Publishers The Incorporation of Ceramic Membranes in MBR Systems for Wastewa- ter Treatment: Advantages and Patented New Developments A. Tolkou 1 , A. Zouboulis 1 * and P. Samaras 2 1 Laboratory of General & Inorganic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-54124, Thessaloniki, Greece; 2 Laboratory of Water & Wastewater Technologies, Department of Food Technology, Alexander Technological Education Institute of Thessaloniki, GR-57400 Thessaloniki, Greece Received: October 09, 2013 Revised: November 13, 2013 Accepted: November 17, 2013 Abstract: The membrane biological reactor (MBR) configuration has proven to be optimal for treatment of many indus- trial wastewaters, especially when optimized treatment efficiencies are an important consideration. Ceramic MBR is being consolidated as a reliable technology for industrial applications, due to the benefits of the system, while ceramic mem- branes may be an adequate alternative for anaerobic MBR application, due to evidence of low membrane fouling rate and the ability to rigorously clean their surface without at the same time reducing the effective membrane life. This review summarizes Recent Patents on Engineering that disclose key data for both the functioning of MBRs and the use of ce- ramic membranes. Specifically, an advanced control system for a membrane bioreactor wastewater treatment plant is dis- closed, while an integrated biological treatment coupled to membrane filtration is proposed for advanced nutrients re- moval and reuse of treated waters. Recent studies have been focused on the production of a specific bioceramic membrane with selective adsorption effects and simultaneous digestion ability. Bioceramic membranes may provide effective carbon sources and required minerals to activated sludge microorganisms, while they can be used as biological media filter mate- rial for air filtration and wastewater treatment. Furthermore, bioceramics may adsorb phosphate ions and remove oxygen rich components such as nitrates from aqueous solutions. Keywords: Bioceramic, ceramic membranes, control system, MBR systems, water treatment, wastewater treatment. 1. INTRODUCTION Membranes can be manufactured from various materials, such as ceramics, organics or metals [1] Table 1. Organic membranes are most commonly applied in water treatment, including a wide variety of membrane materials, pore sizes, pore size distributions, membrane configurations and pro- duction processes. The main benefit for the application of organic membranes is associated with the manufacturing costs. Ceramic membranes are about 10 times more expen- sive than organic membranes [2]. Other differences in the characteristics of ceramic and organic membranes can be found in resistivity against cleaning agents, hydropho- bic/hydrophilic properties, mechanical strength etc; for ex- ample, ceramic membranes have a significant resistivity against very high trans-membrane pressures and tempera- tures. Organic membranes, like cellulose acetate membranes, are usually sensitive to oxidizing agents or the biological activities of the medium where they are immersed. The membrane structure can be isotropic or anisotropic. Isotropic membranes have a uniform composition and struc- ture throughout. Anisotropic (or asymmetric) membranes consist of a number of layers, each one having different structure and permeability [1]. *Address correspondence to this author at the Department of Chemistry, P.O. Box 116, Aristotle University, GR-54124 Thessaloniki; Tel: +30-2310- 997794; Fax: +30-2310-997730; E-mail: zoubouli@chem.auth.gr The Membrane Bioreactor combines the biological acti- vated sludge process with a membrane filtration step for the separation of activated sludge solids from the water phase. Ceramic MBR can be a very good alternative for industrial wastewaters attributed to its robustness and reliability, as well as due to indirect but important benefits linked to the reduction of the bioreactor volume and to lower sludge pro- duction [4]. 2. MBR SYSTEMS 2.1. MBR Technology MBR technology is considered the most advanced tech- nology for wastewater treatment, while Membrane Bioreac- tor systems have become a promising wastewater treatment technique combining activated sludge and membrane separa- tion; it is a process resulting in a high quality effluent inde- pendent of settling characteristics of the biomass. Membrane bioreactors have several advantages over the conventional activated sludge systems, including stable and high effluent quality, easy operation and complete removal of bacteria. However, membrane bioreactors may have several draw- backs due to membrane fouling, which therefore result to higher operation and maintenance costs than conventional systems [5]. The membranes can be incorporated in the biological process in two ways: