Domestic WWTP up to 25 people (DC)

Purpose of the Domestic WWTP (DC)

Plant is used for wastewater treatment of small sources as family houses, cottages, week-end houses, and the like that cannot be connected to municipal sewerage system. It purifies wastewater usually produced by households including bathrooms, washing machines, dishwashers, washrooms and others. Domestic wastewater treatment plants (abbreviated as "DC") are designed to serve up within the range of 2 to 25 PE (Population Equivalent).

Description of design

Reactor of domestic wastewater treatment plant is a cylindrical plastic shell integrated with conical sedimentation - separation tank and aeration system including a compressor (blower). Final sedimentation tank divides the reactor in two sections: inflow (activating, denitrification) and outflow (sedimentation). Wastewater flows in the activation zone through a debris trap catching mechanical debris. Then it is mixed with activated sludge when microorganisms, within the sludge, start acting on substances in wastewater thereby starting the treatment processes. In sedimentation tank water is separated from sludge and flows out through an effluent through and sludge is pumped back to the first section with an air-lift pump.


Essentially, the bioreactor combines all functions of conventional biological advanced treatment plants it operates with low sludge load, higher sludge age and reaches higher treatment performance. Reductions of BSK5 and Total Suspended Solids (SS) under 30 mg/l are easily achievable. If observing the Operating Regulation of Wastewater Treatment Plants the below tabulated values can be obtained.

Dimensions of a DC: Circular Tank of diameter 2,3m and height 2,02m.
People equivalent: Suitable up to 25 people

Average Input (daily):
Q24 = 4,0 m3 ημερησίως (200 l/άτομο/ημέρα)
Max. Input (daily): Qd max = 5,0 m3/ημερησίως
                           Qh max = 4,0 m3/ώρα
                           Q  min   = 1,0 m3/ημερησίως
BOD5   =  60 g/pers/day  1,5 kg/d    300 mg/l
COD    = 120 g/pers/day  3,0 kg/d    600 mg/l
 SS    =  55 g/pers/day  1,5 kg/d    275 mg/l
NTOTAL =  11 g/pers/day  O,3 kg/d    55 mg/l
PTOTAL =   3 g/pers/day  0,08 kg/d  


  • BOD5  25 – 35 mg/l
  • COD    80 – 120 mg/l
  •  SS     30 – 35 mg/l


A trained person is required to work on the DC  1 hours per week, outside the period and annual maintenance.
The operation of the DC will be described in detail in the operation manual.

The Domestic Plant DC contains:

  • Separator
  • Blower
  • Ventilation system of fine bubbles
  • Sludge recirculation pumps
  • Automation
  • Reservoir Sedimentation