BASIC MEMBRANESAN OPERATORS AND OWNERS INTRODUCTIONTO MEMBRANE BIOREACTORS,SIZING CRITERIA, SURROUNDING SYSTEMSAND EXPECTED TRENDS IN THE INDUSTRY

摘要

While designing membrane bioreactor facilities over the past four years, I have listened to manyrnpresentations and toured numerous facilities. The presentations have focused on the membranesrnand its performance ability. The tours and design experience has given me the opportunity to seernthat the membrane process is more than just membranes. Critical to the membrane design is thernsite specific conditions and the numerous support systems that compliment and surround thernmembrane units.rnDifferent from the many papers and presentations that I have seen or heard, this paper providesrnthe operator an introduction to membranes, critical site specific sizing criteria, and the manyrnsystems that compliment the performance of membranes and surround the actual membranernunits. The paper has been prepared in the perspective of the Operator and Owner by breakingrnout each support system and its function. Operators, Owners, Engineers and the Manufacturersrnneed to be more attentive to the surrounding systems of each design as membrane plants becomernlarger and the application more varied. This paper provides an Operator and Owner a basicrnunderstanding of membranes, systems surrounding the membranes and the aspects of arnmembrane design.rnInitially, various membrane classifications and applications will be defined. From this point thernfocus will move toward Membrane Bioreactors. The reader is introduced to typical membranernprocess configurations and variations with respect to conventional activated sludge processes.rnBasic terminology is provided as well as the mechanics of flat plate and hollow fiber membranes.rnAfter providing the reader with a basic understanding of membranes, the membrane activatedrnsludge process is placed in the overall plant. Preliminary treatment is discussed with the variousrntypes of equipment available for screening and grit removal. The importance of preliminaryrntreatment before a membrane bioreactor and the critical design parameters of the equipment arernreinforced. The next process, the membrane bioreactor is examined based on critical sizingrncriteria. Differences are discussed between NPDES permit sizing criteria, membrane activatedrnsludge process sizing criteria and possible hydraulic configurations. Types of post treatmentrnfacilities are then presented. The membrane bioreactor impacts on the sludge process and sludgernproduction completes the plant overview.rnThe paper focuses next on the systems that surround and support the two leading membranernmanufacturers, GE – Zenon and Enviroquip, a Division of Eimco Water Technologies. Thisrncomparison identifies the similarities and differences between the two types of membranernprocesses, since each are a different type of membrane, hollow fiber and flat plate respectively.rnSurrounding support systems include:rn1. the return activated sludge systems,rn2. aeration blower system,rn3. membrane blower system,rn4. membrane units,rn5. permeate system,rn6. maintenance system,rn7. chemical systems, andrn8. performance monitoring systemsrnWhen appropriate, illustrations or schematics are provided of each support system with arnsummary of components, function and purpose.rnThe paper is concluded with a general comparison between the membrane support systems, arngeneral philosophy of each membrane manufacturer’s approach to the process technology, arnglobal design approach to assist the Operator and Owner during design and what is possibly onrnthe horizon from the manufacturers.