Positive aqua solutions-AS™ takes a fresh look at activated sludge systems to overcome the traditional mixing and oxygenation inefficiencies to save time and  energy. Activated sludge process plants are the most widespread technology in wastewater purification. They can be found in different climate conditions from the Tropics to the Polar Regions, aboard ships and at extreme elevations. Activated sludge systems can treat blackwater, brown water, grey water, feacal sludge and industrial wastewater as long as the pollutants to be treated are biodegradable. The term refers to a natural suspended aerobic sludge consisting of flocs of active bacteria, which consume and remove aerobically biodegradable organic substances from screened effluent.


Used in a controlled environment nutrients and pollutants can be removed on a much larger scale than would naturally occur in water bodies. The most critical action in the process is the delivery of free oxygen (O2) for bacterial growth. O2 is traditionally provided via mechanical paddle, disc, spray and turbine aerators. These inefficient delivery systems consume approximately 60 to 75 percent of the net power demand for a typical activated sludge wastewater treatment plant.


Pas-AS™ was developed to efficiently deliver this fundamental element and improve process efficiency through thermal destratification. Pas-AS™ innovative 'bottom up' approach provides both favourable vertical thermohaline circulation and surface movement to maximise oxygenation with the minimum of energy input. Pas-AS™ revolutionary design further reduces the treatment plants footprint through the constructing of much deeper selectors. The reduced surface area of the selector produces far less heat exchange, allowing the ground temperature to maintain a constant liquid temperature ensuring longer aerobic bacterial survival.

How can Pas-AS™ help?

Pas-AS™ advanced aerobic treatment is best suited to municipal and industrial waste waters of medium strength. The land required for treatment is 80% less than that of an equivalent open anaerobic lagoon system and mitigates the production and release of harmful Green House Gasses.


We can further show compelling evidence of the financial benefits and green credentials of  Pas-AS™  compared to other biological treatment products on the market. 


The Pas-AS™ activated sludge treatment systems are  suited to a range of municipal and industrial effluents including;

  • Pulp and Paper

  • Rubber and Latex Mills  

  • Crude Edible Oil Mills

  • Cattle and Poultry Farming

  • Animal Husbandry

  • Mining Industry      

  • Cooling Towers

  • Municipal Sewage

  • Breweries & Distilleries


Pas-AS™ optional intelligent control and reporting systems include telemetric abilities which enable you or our technical teams to remotely monitor, diagnose and troubleshoot biological issues irrespective of their geographical location.

Figure 1. cross section of a Pas-AS™selector
Figure 2. Pas-AS™ mixed selector and extended aeration