APEX 3 Stage Domestic and Commercial Sewage Treatment Plants
These type of domestic/commercial sewage treatment systems comprise of a small electrically driven packaged plant, usually all contained in a single tank.
These types of sewage treatment plant are similar but have some key differences.
SAF = Submerged Aerated Filter
MBBR = Moving Bed Biofilm Reactor
The sewage is first settled in a Primary Settlement Tank to remove the solids, which settle to the bottom and form a Sludge. This is removed, usually annually, by tanker.
The liquid part of the sewage passes into the digestion chamber, or 'Biozone', where air is introduced. The organic matter pollutants in this liquid are digested by aerobic (oxygen breathing) bacteria which colonise the media (filter bed).
The cleaned liquid then passes to a final settlement tank stage to remove the fine solids.
The difference between SAF and MBBR is how the media is installed in the tank. In a SAF system the media is static, whereas the media in an MBBR sewage treament plant is mobile. This is a key difference because SAF plants are less able to stop the media blocking becuase "dead zones" always form. More maintenece is required therefore SAF sewage treatment plants have higher running costs due to the requirement to clean and replace the media. MBBR systems constantly circulate the media and "dead zones" cannot form. This reduces the maintenance requirments and improves treatment efficiency.
The treated wastewater effluent can be discharged to a Soakaway Drainage field system, ditch, or watercourse, (subject to Local Authority and Environment Agency Consents, if applicable). Traditional Soakaways are not allowed for sewage systems.
Maintenance, (which can be expensive, particularly for some package sewage treatment systems) and emptying of the plant to remove the settled solids, will be required at regular intervals. This is usually annually for a single dwelling domestic sewage treatment plant and 2 to 6 monthly for a multiple dwelling unit, as the settlement tank is comparatively smaller in larger, multiple house units.
Our APEX three stage wastewater treatment plant is different, as it uses the settled solids in the first Primary Settlement Tank as a source of food for the bacteria in the Biozone. It uses an automatic process to trickle-feed the bacteria, even during holiday periods when no-one is using the sewage system.
Our SAF & MBBR sewage treatment plants cope very well with fluctuating flow rates and underloading, which is a problem with many residential sites, campsites at the beginning and end of the season and pub trade during weekdays.
Most sewage treamnet plants can only work down to 50% of their maximum design loading.
APEX works successfully down to 20% of the design size.
CYCLONE works successfully down to 10% of the design size.