Copa MBR Technology®
The Copa MBR Technology® process produces a discharge permeate (water) that can be re-used for toilet cisterns, wash-down, irrigation and more.
Applications
• For the treatment of a wide range of effluents: sewage; sludge liquors; industrial wastewater; agricultural wastewater; manufacturing and processing wastewater; and, grey-water recycling for a wide range of re-use purposes.
• For any population equivalent (PE) upwards of 50.
• Configurable for installation in concrete or stainless steel tanks; bespoke or retrofit.
• Also available as a compact or containerised unit.
Operation Principle
The basis of Copa MBR Technology® is the flat sheet membrane; developed as a result of a Japanese Government initiative to produce high quality effluent treatment plants. Copa MBR Technology® is a process that produces a discharge permeate (water) that can be reused for toilet cisterns, wash-down, irrigation and more.
The permeate from the process is typically:
• < 5:5:5 BOD:SS:ammonia;
• free of pathogens, viruses and bacteria;
• complies with the World Health Organisation standards for Unlimited Irrigation;
• complies with the International Maritime Organisationbacteriological limits;
• complies with the EU Bathing Water Directive.
• compliance with the State of California Water Recycling Criteria (Title 22).
The process employs simple flat sheet membrane panels housed in stainless steel (304 or 316) units and aerated by a coarse bubble system below each unit.
A series of these membranes are submerged within an activated sludge treatment tank. The aeration necessary for treatment of the liquors also generates an upward cross-flow over the membranes; essential to keep fouling of the filtration surface to a minimum. An advantage of this design is that the membrane panels are securely retained and do not touch or abrade each other whilst the units also act as a flume to ensure effective tank mixing and even distribution of the biomass.
The membrane panels are manufactured with a pore size in the range of 0.1 to 0.4 microns which in operation becomes covered by a dynamic layer of protein and cellular material. This further enhances the effectiveness of this filtration performance by providing an effective pore size of less than 0.01 microns, which is in the ultra filtration range.
The membrane bioreactor treatment produces a high quality disinfected effluent. The incoming wastewater generally only requires screening and de-gritting prior to entering the membrane bioreactor tank. The process requires no primary or secondary settlement stages and no additional tertiary treatment or UV stages to achieve very high disinfection quality: typically better than 5:5:5 BOD: Suspended Solids: Ammonia.
The hydraulic flow determines the required number of membrane units. Each membrane unit may contain up to 400 flat sheet membrane panels housed within a rectangular box, together with an integral aeration system in the bottom section of the unit.
Treated effluent is removed from the membrane units using gravity head (typically 1 – 1.2 m), or a pumped suction operation can be utilised.
Advantages
Membrane Bioreactor Technology has a number of inherent advantages. The system does not require flocs to be formed to remove the solids by settlement and therefore the biomass can operate at very high levels of MLSS, generally in the order of 12,000-18,000 mg/l, and as high as 22,000 mg/l. This high concentration enables a low tank volume and a long sludge age to be utilised, which substantially reduces sludge production.
The process requires no primary or secondary settlement stages and no additional tertiary treatment or UV stages to achieve very high disinfection quality: typically better than 5:5:5 BOD: Suspended Solids: Ammonia.
Operation and Maintenance
Operating experience of Copa membrane bioreactor plants has consistently shown an effluent of high quality that has little dependence on variations in feed strength: disinfection of bacteria and viruses is to below the EU limits for bathing water or recreational water standards.
By minimising the effect of fouling through controlled cross flow velocities over the membrane surface cleaning is required typically only twice per year using a backwash of very dilute sodium hypochlorite solution into each membrane unit. The process is designed to run without supervision and by using high quality plastics and stainless steel, the membrane panels and units have long life expectancies in the most part beyond 10 years.