The Dryden Aqua Air Diffusers are the most robust and versatile fine bubble diffusers. Fine bubble diffusion is more effective than coarse bubble diffusion in providing a greater mixing action and aeration efficiency (up to 5 times more efficient).

The diffusers are of semi-flexible construction of 32 mm in diameter and of variable length up to 3 metres depending on the air, oxygen or carbon dioxide through-put required. The diffusers have their own ballast and will stay on the bottom of the aeration tank without the requirement to secure them to the base. This makes our diffusers really easy and quick to install.


- Waste water treatment SBR`s
- Activated sludge aeration
- Landfill & industrial leachate
- Degassing drinking water of THM`s & radon
- Destratification of rivers, lakes & reservoirs
- Aeration of lakes used for the storage of waste-water
- Aquaculture & public aquaria & coastal marine zone

Unique advantages

The Dryden Aqua air diffuser has the benefits of a membrane diffusers and the performance of a ceramic diffuser. The diffusers are ideally suited for clay or plastic lined lagoons  but they are also perfect for tanks, lakes and aeration ditches. Installation in a lagoon very simple, fit an air ring main pipe (usually in MDPE) around the perimeter of the lagoon, fit 1/2" hose on to the air ring main using saddle clamps. Cut the hose to a length that will take it to the base of the lagoon. Fit one diffuser on the end of the hose and throw it into the lagoon. An Installation with 100 diffusers to cater for a PE (Population Equivalent)  of 10,000 can be completed in 5 days.

The air diffusers require virtually no maintenance or cleaning.  In order to avoid biofouling the diffuser should either be running at their designed air flowrate, or turned off. Our air diffusers are used to treat landfill leachate and compost waste water,  the COD can often be over 10,000mg/l with an alkalinity of 2000 mg/l.  Under these conditions, some degree of scaling can occur.  However, because the diffusers are semi flexible, the scale usually just cracks-off the diffuser. 

It is very easy to clean the diffusers,  just pull on the 1/2" hose to recover the diffuser,  give it a quick shake and brush, and then throw back into the water. Cleaning of 100 diffusers takes about 2 hours. Frequency of cleaning depends upon the quality and temperature of the water,  but it is usually between once a week to every six months. The diffusers can be maintained while the air blowers are running and lagoon or tanks are full of water. 

Sizing a system

  • 1 x diffuser code 7008, 3m long 10 cubm/hr will supports 50 to 100pe (population equivalent) municipal effluent treatment. If the tank is less than 3m in depth, use 1 diffuser per 50pe.
  • 1 x diffusers code 7008, 3m long running at 10 cubm/hr will dissolved into the water between 18kg and 27 kg of oxygen per day, the deeper the aeration tank the higher the efficiency.
  • Transfer efficiency,  for 1 kw of energy expended  5 kg of oxygen will be dissolved into the water
In order to size an installation for waste water treatment, determine the COD loading in kg/hr.  For example is the water flow is 50m3/hr at 400mg/l of COD,   COD = 20 kg/hr = 20kg of oxygen per hour.  In order to treat this water you will need 20 x diffuser code 70008 delivering 10m3/hr of air, each = 200m3/hr of air.

If the water contains a high concentration of ammonium,  calculate the ammonium level in Kg/hr, for every 1 kg of ammonium  = 5 kg of COD, then use 5 x air diffuser  for every 1 kg/ammonium/hr

The Dryden Aqua diffusers are usually twice as efficient as any other diffuser on the market and up to 4 times more efficient than surface aerators. Surface aerators waste a huge amount of kinetic energy simply throwing the water up into the air, they also create an aerosol of bacteria. We do not recommend the use of venturi type injectors for activate sludge or extended biological aeration systems. Injectors tend to cause gas supersaturation with nitrogen, bulking of the sludge and foam formation. The injectors also smash up the bacteria floc and reduce performance of the bacteria.  4% of all the energy used in the UK is aeration of wastewater, the Dryden Aqua diffusers would reduce this energy demand by 50%.

Description        Diffuser
Weight Kg
Air Flow m3/hr (+/-20 %)Oxygen Transfer kg of O2/day per diffuser at different depths at 20 °C and 50 % O2 saturation diameter
         2 m  3 m  4 m 32 mm 
70000 0.33 m Diffuser 0.5 1 2 2.5 32 mm
70001 0.66 m Diffuser 1.0 2 4 5.0 6 32 mm 
70002 1.00 m Diffuser 1.5 3 6 7.5 9 32 mm 
70003 1.33 m Diffuser 2.0 4 8 10 12 32 mm
70004 1.66 m Diffuser 2.5 5 10 12 15 32 mm
70005 2.00 m Diffuser 3.0 6 12 15 18 32 mm
70006 2.33 m Diffuser 3.5 7 14 17 21 32 mm
70007 2.66 m Diffuser 4.0 8 16 20 24 32 mm
70008 3.00 m Diffuser 4.5 9 18 22 27 32 mm