Membrane Bio-Reactors (MBR)
Membrane Bioreactor (MBR) systems offer several operational and economic advantages compared to conventional wastewater treatment plants. By incorporating membrane technology, MBR systems eliminate the need for secondary clarifiers and tertiary treatment. This allows for increased performance with a smaller footprint.
MBR systems can produce effluent standards up to an order of magnitude better than typical aerobic wastewater treatment units. MBR systems are typically installed in environmentally sensitive areas where high discharge water quality standards are required. The Martin's si-Claro membrane treatement that TMC supply meets the European standards for bathing, and a feed supply for reverse osmosis
The ultra-filtration membrane adopted for wastewater treatment physically separates smallest particles down to colloids from liquids on the basis of its defined pore size (<0.1 µm). All bacteria are excluded including larger viruses, post membrane the effluent is radiated by UV to sterilize any viruses that pass the membrane. We utilise user-friendly flat membranes made of organic polymers which, in combination with the sophisticated filter design, effectively reduce clogging of the filter due to hairs, fibres or other unhygienic coarse matter.
Domestic MBR pack. TMC uses superior membranes technology designed to operate in waste water systems. TMC MBR systems produce high quality discharge water which exceeds Australian standards.
How MBR Systems Work
TMC supply within the treatement system the siClaro FM filter designed for the separation of activated sludge from biologically treated water.
The flat sheet membranes are assembled into a filter module, several modules are combined to make a filtration system. During the filtration operation the biologically purified wastewater is drawn from the outside inwards by means of a low pressure vacuum created by a self-priming centrifugal pump (note exceeding 300mbar). Particulate mater larger than the membrane pore size will be captured on the outside phase. This way the submerged membranes present a physical barrier to the activated sludge reducing the suspended solids to effectively zero.
siClaro membranes do not need any kind of backwsh. Membrane cleaning will be done continuusly with air scouring. Air flow is introduced at the bottom of the membranes to create a turbulent liquid mixture cross flow that scubs and cleans surface and prevents the polarisation and thickening of suspended solids within the membrane modules. During the filtration operation the membrane becomes covered by a dynamic layer of solids and hydraulic resistance increases. Over a period of time some fouling and scaling may accur which cannot be removed by physical cross flow alone. As the transmembrane pressure approaches the maximum allowed pressure limit, chemical cleaning will be required. This will restore the initial transmembrane pressure and maintain the flow at the desired level. Under normal operation 1-2 cleaning cycles will be required during the year.
In domestic or small commercials the membranes are removed from site for cleaning and replaced. Larger commercials membranes are cleaned insitu on site.
Domestic MBR pack. membranes are changed out with clean, regenerated packs during routine system service
Domestic MBR stack. The membrane cartridge is loaded into a stainless steel rack which is placed in the aeration chamber.
Installation of a commercial MBR module at a winery in the wine growing region of Margaret River Western Australia.
Domestic MBR stack and rack prior to membrane change out.
Commercial vs Domestic MBR Systems
Membranes remain the property of TMC as it is difficult for the original pack to be returned to the clients system. TMC provide a lifetime guarantee of the membrane pack +10 years by leasing the pack to the client that becomes part of the servicing contract. This is most common in domestic and small commercial plants. Larger commercials (+100kL/d ) the packs are cleaned insitu and do not leave site. Each commercial site has a specific agreement on the membrane ownership and servicing arrangements.
The si-Claro MBR systems are modular; domestic systems contain one or two packs, each pack has 6m2 of membrane surface area where commercial systems the packs are clustered into trains. Individual trains are clusters of packs typically 4-12 each train can be taken offline for cleaning leaving the remainder to operate during the cleaning process. The process is repeated untill all trains are cleaned.
Commercial TMC MBR's have protection devices pre membrane to protect the membranes from damage. Fine screens are installed to trap sharps and other metailic materials preventing them from comming in contact with the membrane surface. DAF's and VGS devicies are installed to collect fats (FOG's) that will otherwise clog the membrane and require more cleaning cycles than required.
Domestic MBR's have minimal protection relying on settlement in chambers pre membrane. Build up of fats in the primary chamber over extended perids 3-5 yrs will require pump out similar to standard ATU's. The servicing program will identify issues that may arise long before any problems occure.
Aerobically treated effluent is filltered through the membrane structure.