ZPM - Zeta Potential Static Mixer


Manufactured by Dryden Aqua from 100 %, 316 grade stainless steel, or mdpe plastic & titanium for marine applications that flanges directly into the pipework. The Dryden Aqua ZPM is a cavitating static mixer used for the injection of coagulants and flocculants prior to mechanical filtration by sand or Dryden Aqua AFM® (Activated Filter Media) for potable water as well as wastewater. The Dryden Aqua ZPM, cavitates the water and increases the oxidation potential by over 100 mv with no addition of chemicals. The Zeta Potential drops as redox potential increases to initiate coagulation and flocculation reactions. The ZPM is also fitted with the connections to take two injection points for liquids such as Dryden Aqua products

  • ACO for photo-catalytic oxidation of water
  • APF All PolyFloc, a multi-spectrum product for phosphate control, coagulation and flocculation reactions
  • NoPhos, a phosphate precipitating product

Our ZPM’s can also be used as an injection point or gas, such as carbon dioxide, oxygen or ozone.

Key Points:

  • The only cavitating static mixer
  • Increase oxidation potential by > 100 mv
  • Injection point for coagulants & flocculants
  • Injection point for chlorine, ozone, or any gas
  • Essential for the efficient use of coagulation and flocculation chemicals
  • Cavitates the water, imploding bubbles damage the cryptosporidium oocycsts and renders them usceptible to oxidation.

Filtration performance

Dryden Aqua AFM® filter media will nominally remove particles down to 5 micron, sand will remove particles down to 15 micron. However when you apply efficient coagulation and flocculation using a ZPM with APF, it is possible to consistently remove particles down to 0.1 micron with AFM® as well as well as a high percentage of dissolved chemicals such as priority substances.

The ZPM amplifies flocculation reactions to make the suspended solids larger and easier to remove by the filters. A ZPM unit should always be used prior to AFM® or sand filters as an injection point for APF. Continuous coagulation and flocculation must be used to insure physical removal of cryptosporidium oocysts, giardia, nematodes and dissolved organics. The Dryden Aqua ZPM unit makes the process much more efficient, especially when combined with AFM®.

Priority substance, organics and chlorine demand

ZPM zeta potential mixer in combination with APF will drag most of the dissolved organics and pollutants out of the water by coagulation and turn them into particles that can then be removed by the filters. Research is in progress for new high oxidation potential coagulants that will specifically focus on a wider range of priority substances for removal by the catalytic surface of AFM®.

The ZPM is essential for the coagulation reactions, the water must be mixed within 1 second for the reactions to progress. Dryden Aqua has developed APF, which is a new multi spectrum combined coagulant and flocculent designed to work with the ZPM. The combination of APF, ZPM and AFM® filter media collectively can reduce the chlorine oxygen demand of potable water by up to 80 % in some cases. Efficient mixing and cavitation is therefore seen as an essential prelude to AFM® filtration.

Water becomes self-sterilising

On passage of water through a ZPM, the zeta potential of the water is shifted into a lower zeta potential, this increases redox potential and surface tension which makes it extremely difficult for bacteria to survive in the water, yet there are no chemicals in the water. The system has changed the way the water molecules relate to each other, also referred to as the hydrogen bonding liquid crystal phase.

ZPM cavitation

Our ZPM generate nano-bubbles that have a high degree of stability and are attracted to the surface of particles such as viruses, bacteria, fungal spores and protozoa or the surface of organic molecules.

On touching a solid surface the nano-bubbles collapse to release energy directly onto the cell membranes. The localised pressure is 2000 bar and temperatures up to 3000 °C are generated. This has the effect of disinfecting the water without the use of chemicals. When a nano-bubble collapses on an organic molecule, the energy released will oxidise the molecule. Any nano-bubbles that do not collapse will auto destruct after a few seconds.

Nano Bubbles

Nano-bubble implosion formed by ZPM, when bubble implodes on an oocysts or a bacteria, to organism may be killed or rendered susceptible to oxidation by chlorine

      Pressure loss

Item Nr.


length / weight

0.2 bar
1,5 m/s

0.3 bar
2,0 m/s

0.5 bar
2,5 m/s


ZPM DN 32-2 / 1" ET 

140 mm / 0.35 kg

6 m3/h

7 m3/h

9.5 m3/h


ZPM DN 40-3 / 1“ ET

235 mm / 0.75 kg

5 m3/h

6.5 m3/h

8.5 m3/h


ZPM DN 40-2 / 1½“ ET

195 mm / 0.75 kg

10 m3/h

12 m3/h

15 m3/h


ZPM DN 50-3 / 2“ ET

300 mm / 1.2 kg

8.5 m3/h

13 m3/h

21.5 m3/h


ZPM DN 50-2 / 2“ ET

240 mm / 1.2 kg

15 m3/h

23 m3/h

30 m3/h


ZPM DN 65-3 / 2½“ ET

332 mm / 2.8 kg

20 m3/h

27 m3/h

40 m3/h


ZPM DN 80-3 / 3" FL

419.6 mm / 11.2 kg

20 m3/h

30 m3/h

45 m3/h


ZPM DN 100-3 / 4" FL

519.6 mm / 14.4 kg

50 m3/h

60 m3/h

80 m3/h


ZPM DN 125-3 / 5" FL

640 mm / 21.0 kg

70 m3/h

85 m3/h

115 m3/h


ZPM DN 150-3 / 6" FL

759.6 mm / 26.8 kg

100 m3/h

125 m3/h

170 m3/h


ZPM DN 200-3 / 8" FL

979.6 mm / 41.2 kg

175 m3/h

220 m3/h

290 m3/h


ZPM DN 250-3 / 10" FL

1219.6 mm / 58.6 kg

260 m3/h

325 m3/h

420 m3/h


ZPM DN 300-3 / 12" FL

1496 mm / 77.2 kg

385 m3/h

475 m3/h

500 m3/h


ZPM DN 350-3 


410 m3/h

540 m3/h

680 m3/h


ZPM DN 400-3 


520 m3/h

710 m3/h

900 m3/h


zpm druckverlustkurve dn 32 65       Full Resolution DN 32 - DN 65

 zpm druckverlustkurve dn 80 125  Full Resolution DN 80 - DN 125

zpm druckverlustkurve dn 150 300Full Resolution DN 150 - DN 300