The Problem

Over 50% of the operating cost for wastewater treatment plants are spent powering aeration systems. With rising energy costs and a trend toward reduced energy consumption and greenhouse gas emissions, existing wastewater treatments are under constant pressure.


Existing biological wastewater treatment technologies are dated and lack in addressing today’s requirements: such as sustainability, process and energy efficiency.


Today’s biological wastewater treatment technologies still use principles established in the beginning of 1900’s. The principles can be basically simplified into:

  • aerating the mixed-liquor of wastewater and bacteria 
  • holding the mixed-liquor for a certain time to allow bacteria to absorb pollutants
  • then separating the bacteria from the treated wastewater
  • finally discharging the effluent to a receiving waterbody

One of the commonly used methods, diffused aeration suffers from:

  • Low efficiency (only 3% to 15% of oxygen can be transferred to the mixed-liquor) 
  • High energy consumption (Large carbon footprint)
  • Complicated maintenance (requires emptying big pools for repair or if not possible to empty then hiring professional wastewater divers)

Our Solution

Our patented technology, PIJAMA™ (Plunging Immersed Jet Aspiration & Mixing Apparatus) uses vertical jet streams to mix and transfer a fluid into a liquid body without using aid from blowers or compressors. The liquid is recirculated by means a pump in the tank for efficient mixing. When needed atmospheric air (or other gas) can be aspirated and sheared into tiny bubbles that are driven down to the tank bottom before bouncing back to the surface. This results in increased oxygen transfer and mixing efficiency.  


PIJAMA is designed to retrofit and upgrade the capacity of existing conventional systems and to cost-effectively convert them into biological nutrient removal systems by means of installing new and efficient equipment, which is flexible for further upgrade opportunities from suspended growth to fluidized attached growth, as well as upgrading to contemporary anoxic treatment processes within the existing infrastructure (no alteration of existing infrastructure is required). Although PIJAMA is also designed for upgrading aeration systems with high purity oxygen, the ultimate target market is the leading edge anoxic biological treatment; therefore the “MixAnox“ is selected as the brand name.

PIJAMA™ Benefits

1.  Dollar savings 

     (a)  Less capital cost (less initial cost and less HP than big-name mixers)
               -    Capital also saved through reduced HP requirements and less electrical infrastructure, reduced                             conductor size, smaller MCC, etc.

     (b)  Less operational costs 
               -     Lower power consumption (up to 50% hydro savings)
               -     Lower labour hours (reduced hours for maintenance)


2.  Convenience in Operation and Maintenance 

     (a)     Wet installation is often possible (without interfering or stopping the existing mixing/aeration system) 

     (b)     Operation simplicity as the equipment consists of a pump, pipeline, and jet ejectors

              (95% non-proprietary parts)
     (c)     Maintenance ease and speed (fewer labour hours) 
               -    critical parts of equipment readily accessible from outside (WITHOUT any need for emptying

                     large aeration basins) 
              -     only moving part is a common wastewater pump which is readily mastered by any WWTP operator
              -     spare parts locally available 

3.  Flexibility 
     (a)     pump selection can be made to client's preferred brand  
     (b)     one equipment is used for mixing aerobic, anoxic, and/or anaerobic reactors (supporting

              biological nutrient removal) 

     (c)     equipment can further be designed for supporting contemporary biological nutrient removal methods:
              -     swing reactors (alternating aerobic/anoxic conditions in one reactor)
              -     simultaneous nitrification/denitrification 
              -     moving bed bioreactors (MBBR or IFAS)
              -     high purity oxygen (HPO) activated sludge
              -     others: SHARON, ANAMMOX, DEMON, 
              -     combining any of the above (such as ANITA-Mox)

              -     intermittent ozone injection to boost 

    (d)     equipment can also be designed to aspirate atmospheric air for average flow loadings and capable of

             using HPO (high purity oxygen) to boost the capacity in response to peak loadings to eliminate/minimize

             process upsets and ensure meeting compliance targets. 


4.  Process Performance / Environmental Impact 
     (a)     improved process efficiency (by means of creating tiny air bubbles, effectively carrying them to the

              bottom of the aeration tank and achieving improved oxygen transfer efficiencies) 
     (b)     carbon foot-print reduction (due to energy savings and process improvements)
5.  Made in Canada

     (a)     Developed in Ontario, Canada with local resources

     (b)     Patented technology in Canada, the USA and the EU


PIJAMA™ Usages





PIJAMA's Usage In Different Process Conditions





(O3 - H2O2)




Suspended growth (Activated Sludge)

Attached growth, fluidized (MBBR)


Combined (IFAS or ANITA-Mox)



* Alternating any of the above process conditions in a single reactor


 1.    an aeration device (no extra blower required)   [ aerobic ]


 2.    a mixer intermittently aspirating air when desired [ anoxic ]


 3.    a gentle mixer for un-aerated reactors  [ anaerobic ] for biological nutrient removal


 4.    a high purity oxygen aeration system [ highly aerobic ] used during peak loads


 5.    a hydrogen-peroxide/ozone system [ oxic ] for converting COD to BOD for further treatment or advanced            oxidation process)


 6.    a novel mixing and aeration system for mixing wastewater reactors where [ plastic media are artificially

       added ] to enhance performance (MBBR and IFAS systems) especially for anoxic and swing reactors used in

      ANITA-Mox systems


 7.   a novel mixing system for anaerobic digestion of biosolids by enabling intermittent ozone injection for

      improving process performance and gas production rate


 8.   a mixing and gas transfer system for the treatment of mining tailings
      (Ex: cyanide detoxification with sulfur dioxide)


 9.   other (please contact us if you need a custom mass-transfer apparatus made for your needs)  



Print Print | Sitemap
© MixAnox Systems Inc. - 1&1 IONOS MyWebsite