Ecogent are the New Zealand market partners of Environmental Dynamics International (EDI) one of the world’s leading providers advanced technology aeration and biological treatment solutions for municipal and industrial wastewater. EDI has been designing and manufacturing diffuser aeration systems since 1975 and has over 7000 diffuser aerations installation in over 100 countries.
Aeration is the heart of a biological wastewater treatment process and will typically account for 50 to 80% of a treatment plants running costs. Aeration efficiency is the key to meeting design objectives and with the right aeration technology and design treatment performance can be maximised and operating costs minimised.
Through EDI, Ecogent has access to decades of acquired industry knowledge and experience and a full line up of products and systems. This gives us the ability to deliver high value, cost effective aeration solutions for even the most challenging wastewater applications.
Consideration of the right combinations of diffuser type and material, diffuser density and configuration and submergence for a particular biological process enables oxygen and mixing requirements to be met and treatment objectives to be satisfied.
Thorough process design combined with an economic analysis allows capital costs to be balanced with operational and maintenance costs to meet client objectives.
Backed up by more over 40 years aeration system design experience from EDI, Ecogent can offer a comprehensive design service for your biological treatment and aeration requirements. Contact Ecogent Engineers today to discuss your aeration project.
Pond treatment has traditionally been the preferred wastewater treatment technology for community wastewater treatment plants across New Zealand.
These are cost effective, low maintenance and generally perform well removing BOD and solids. Many of these ponds are still in operation however as ponds age, contributing populations and loadings grow and consent effluent requirements become more demanding traditional ponds can struggle to meet capacity and are being replaced with more advanced activated sludge technologies.
Fortunately there have been a number of process and technology advances in the field of pond treatment and existing ponds can be upgraded to achieve higher treatment standards, whilst maintaining the traditional advantages of operational simplicity and cost effectiveness.
Contact Ecogent to discuss possible improvements to existing ponds including:
- Revised process objectives
- Partitioning and other hydraulic improvements to prevent short circuiting
- Attached growth media to improve process stability and cold weather nitrification
- Fine bubble diffused aeration systems to efficiently extend aerobic capacity and improve mixing
- Pre-treatment, post treatment and side stream process improvements
- Sludge management strategies to maintain mixed liquor concentrations within optimal range
- Fine bubble and coarse bubble diffuser options
- Floating, fixed and retrievable supports
- FlexAir Discs, FlexAir tubes, FlexAir MiniPanel and Streamline diffusers available
- A range of diffuser materials to suit application including EPDM, PU, silicone
Ecogent supplied over 4000 disc diffusers (225mm diameter) to deliver oxygen requirements to a municipal SBR in Pukekohe, South Auckland.
This North Auckland aeration pond was upgraded with diffuser aeration. It was able to maintain dissolved oxygen level with less than half the energy of the surface aerator in the background.
Have an aeration project for us?
We would love to get involved early! We can provide valuable assistance at all stages of the project from the initial sizing of the oxygen & mixing requirements through to diffuser selection and material recommendations, installation & commissioning and membrane replacements.
Frequently asked questions
Are diffusers efficient at shallow depth?
Yes diffusers should still be considered in shallow applications because oxygen transfer per unit of energy used remains almost constant irrespective of depth. Decreasing depth decreases the total oxygen transfer efficiency but it also decreases the operating pressure and energy required of the blower motor meaning the oxygen transferred per unit of energy remains about constant.
Are diffuser aerators more efficient than surface aeration?
Yes fine bubble diffusers offer superior oxygen transfer and energy efficiency compared to all types of surface aerator. Fine bubble diffusers have energy efficiencies typically >7kgO2/kWhr. Surface aerators typically only provide 1 – 2 kgO2/kWhr.
How long does a diffuser membrane last?
Advanced technology membranes will deliver optimum performance for 3-10 years. For sewage applications, typical design economic life is 5 years with most projects performing beyond the 5-year average. For special wastes, such as special industrial applications or very aggressive wastes, membrane life can be reduced.
Can diffuser membranes be replaced?
Most flexible membranes can be replaced at the end of their design life without replacing the diffuser infrastructure. Environmental Dynamics can provide replacement membranes to suit most diffuser types.