An effluent purification technology that helps municipal, commercial and industrial users to recycle sewage as service water is being introduced to Australia by Elmco Water Technologies-AJM Environmental Services (EWT-AJM).
The Huber Vacuum Rotation Membrane VRM Bioreactor is particularly useful in situations where increasing drinking water shortages require at least partial re-use of treated wastewater as service water, including applications such as irrigation.
The technology is suited to blackwater treatment, industrial wastewater treatment, hotels and high-rise buildings. Capacities extend up to 1000 m3 a day and operating costs are claimed to be around 65% less than alternatives because of the technology’s unique rotating carriage, which significantly reduces air scour demand.
The process involves a system of ultra-filtration membranes submerged within aeration tanks which delivers high effluent quality that claims to meet the most stringent current international regulations.
The Huber VRM system is a combination of biological wastewater treatment and effective solids/liquid separation. Pre-scored wastewater is aerated, clarified biologically and all solids within the flow (particles, bacteria, viruses) are removed by the ultra-filtration membrane in accordance with the low-pressure principle.
By increasing the concentration of the active biomass to 12-16 g/L, the system can improve the efficiency of a conventional wastewater treatment plant without the need to increase tank volumes.
The system also eliminates the need for subsequent secondary clarification tanks, sand filters or a disinfection plant, which are otherwise often required for advanced wastewater treatment. Existing secondary clarification tanks can, however, be used for process optimisation.
Benefits of the system include: compliance with hygienic standards; high concentrations of active biomass allow for a reduction in the aeration tank volume by up to 70%; membrane covering layer removal with minimum energy consumption through sequential cleaning of the rotating membranes; minimum scouring air requirement for covering layer control; reduced energy consumption for scouring air due to the centrally positioned air intake and low pressure; no periodic permeate back washing during filtration; transmembrane pressures are low and tranquil because of the high membrane permeability. This has a positive effect on membrane life and helps to minimise energy consumption; permeate discharge system prevents contamination on the permeate side; and stainless steel design.
The unit can be installed into existing or new concrete tanks or stainless steel or steel tanks.