AS-VARIOcomp N (30 - 300 PE)

A line of equipped wastewater treatment plants designed for sewage treatment. The WWTP can be used for a volume from 30 to 300 population equivalents (PE).
Based on a stable and reliable operation, the plant technology keeps energy consumption to a minimum. This technology uses aerobic biological processes that have been proven by long-term application in practice.

Advantages of the AS-VARIOcomp N:

  • Low operating costs
  • Complete delivery (everything included in the price)
  • Insulated and lockable cover
  • Easy operational handling and reliability
  • Customer support and maintenance services throughout the Czech Republic
  • Possibility of simple conversion from a conventional wastewater treatment plant (WWTP) to the ULTRA type, by the insertion of a membrane module

Description of individual types:

AS - VARIOcomp N
Wastewater flows by gravity to the WWTP and there is no need to have a built-in pumping shaft.

The WWTP is designed for locations where wastewater has to be pumped, due to the height conditions of the inflow.


The AS-VARIOcomp N biological wastewater treatment plant (hereinafter only referred to as a WWTP) continues the proven line of WWTPs known under the trade name AS-VARIOcomp V. The changes result from the requirements of the ČSN EN 12255 European Standard, parts 1-16.
The WWTP is designed for the treatment of sewage from shops, hotels, businesses, and residential units, as well as parts of municipalities. The advantages of the WWTP are its easy adaptability to local conditions and the simple design of the technology.
WWTPs of a larger size can be designed through combinations of the basic line (e.g., a WWTP for 200 PE consists of two WWTPs for 100 PE).

Description of required structural modifications:

- The WWTP must be installed on a reinforced-concrete foundation slab.
- The WWTP for 30-50 PE is equipped with an inlet as extensive as the tank’s footprint.
- The WWTP must be embedded in concrete, incl. the ceiling.
- The connections of the inlet and outlet pipes must be made of flexible joints.
- The blower is installed in a separated plastic and ventilated housing that is part of the delivery of the technology. The plastic housing of the blower may be installed inside the WWTP, or better outside it.
- The electric switchboard can be positioned in a lockable plastic stand near the WWTP, or on the wall of the nearest building (e.g., a warehouse or garage) and interconnected with the blower using a sleeve with the minimum dimension of DN 100 (in the N PUMP version, with the WWTP as well).

Description of how the WWTPs work:

Wastewater flows to the settlement compartment of the WWTP, which at the same time serves as the reservoir for excess sludge. Settling and floating pollutants are captured there. In the activation compartment of the WWTP, mechanically pre-treated water is subject to a final biological treatment. In the secondary settlement compartment of the WWTP, formed sludge flocs settle and treated water is subsequently drained. Thickened sludge automatically returns to the activation part from the bottom part of the secondary settlement tank. A part of activated sludge from the activation compartment is exhausted as excess sludge to the sludge tank.

Unlike the AS VARIOcomp N type, the WWTP is supplemented with a precipitant dosing device to reduce the content of phosphorus in treated water. The precipitant dosing device can be installed inside the WWTP without any additional structural modifications.

Unlike the basic AS VARIOcomp N type, the WWTP also contains a built-in pump sump that is equipped with sludge pumps and a rack basket. Wastewater is pumped directly to the activation part of the WWTP.

Examples of dimensional layout

AS - VARIOcomp 80 N
AS - VARIOcomp 80 N/PUMP

Table of the dimensional range of the AS - VARIOcomp N WWTP

Type Quantity Q BOD5 Length x Width x Height
L x B x H
Height (mm)
of inlet Hv / outlet Ho
Installed power input
PE (m 3 /day) (kg/day) N N/PUMP N N/PUMP N N/PUMP
30N 25-35 4,5 1,8 2000 x 2160 x 2830 2200/2050 min.1100/2050 1250 1320 0,55 1,2
40N 36-45 6,0 2,4 3000 x 2160 x 2830 2200/2050 min.1100/2050 1400 1470 0,55 1,2
50N 46-55 7,5 3,0 4000 x 2160 x 2830 2200/2050 min.1100/2050 1750 1820 0,75 1,4
60N 56-70 9,0 3,6 4000 x 2160 x 2870 2700/2550 min.1100/2550 1900 1970 0,90 1,6
80N 71-90 12,0 4,8 5000 x 2160 x 2870 2700/2550 min.1100/2550 2200 2270 0,90 1,6
100N 91-110 15,0 6,0 6000 x 2160 x 2870 2700/2550 min.1100/2550 2450 2520 1,25 2,0
125N 111-135 19,0 7,5 7000 x 2160 x 2870 2700/2550 min.1100/2550 2700 2770 1,25 2,0
150N 136-155 22,5 9,0 8000 x 2160 x 2870 2700/2550 min.1100/2550 2950 3020 1,25 2,0

Table of guaranteed values

The guaranteed values of the outlet of the AS - VARIOcomp N WWTP will be met if the design parameters and installation and operating conditions are observed. With the AS - VARIOcomp N/P or AS - VARIOcomp N/PUMP/P WWTP types, the outlet concentration of phosphorus P total = 2 m/l can also be guaranteed.

Indication "p" values "m" values
BOD5 5 (mg/l) 25 60
COD (mg/l) 100 150
Solids (mg/l) 30 60

The guaranteed parameter values correspond to the specific requirements of the Czech legislation, while the guarantees for other countries are specified and offered individually and/or upon request. In doing this, it is issued from the values measured in the type test according to EN 12566-3+A2.


Selected references

AS-VARIOcomp 30N/PUMP, location: Vír, CZ
AS-VARIOcomp 50N/PUMP, location: Ostrava-Antošovice, CZ
AS-VARIOcomp 80N, location: Neslovice, CZ
AS-VARIOcomp 80N, location: Olomučany, CZ
AS-VARIOcomp 200N, location: Damníkov, CZ
AS-VARIOcomp 250N, location: Podlesí (Ústí nad Orlicí), CZ