Elmco Water Technologies-AJM Environmental Services effluent recycling technology

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.