Wastewater Treatment Plants - Aquatec VFL, s.r.o.

General information – residential wastewater treatment plants

AT 6 to AT 12 packaged residential wastewater treatment plants treat sewage of detached houses. The treated wastewater can be further discharged in surface or ground waters or, as the case may be, reclaimed, using it to water lawns and greenery.

In compliance with requirements of European norm EN 12566-3, our residential wastewater treatment plant was subject to a long-term efficiency test of purification, comprehensive tests of static resistance, watertightness, durability and the checking of dimensions and accessibility. After completing proof of its conformity, performing the initial tests of the type and introducing in-house control of the manufacturing plant, the manufacturer issued a declaration of conformity that is fully in compliance with the EU legislation. Upon the completion of the aforesaid process, the manufacturer is authorised to label its AT to 50 EO wastewater treatment plants with the CE mark of conformity.

Basic description
The wastewater treatment plant consists of an all–plastic reactor with an inner built-in technological structure. The maximum achievable purification effect is based on the utilisation of low-load activation technology with aerobic sludge stabilisation. The AT wastewater treatment plant is covered with a removable, lockable PP cover. The AT wastewater treatment plant uses a tried and tested system of continual biological purification of wastewater with an integrated accumulation of abruptly inflowing water. This technology is protected in Slovakia by utility models UV 4324 and UV 2750 and internationally by patent No. EP1919833. Our purification technology ensures the high quality of treated water as well as low investment and operating costs. The technology is also known under the international name of Vertical Flow Labyrinth – VFL®.
The AT wastewater treatment plant is delivered based on a binding order, while payment and delivery conditions are subject to mutual agreement between the customer and supplier.

Treatment process
It consists of a sequence of several technological processes. Wastewater flows to a non-aerated space, where the nitrogen is biologically degraded and the conditions are created for the partial biological degradation of phosphorus. The preliminary mechanical purification of inflowing wastewater and the decomposition of solid contamination also occur here. The non-aerated activation space is divided into several inner partition walls creating a vertical flow labyrinth where internal circulation has been established.
Further, wastewater flows gravitationally into an aerated space with low-loaded activation, where, under the presence of oxygen, the biological degradation of organic contamination as well as the nitrification of ammonia nitrogen is brought about.

Air is supplied to the aeration system by diaphragm compressors or blowers with a side duct (high-pressure fans) that are placed outside the biological reactor. The pressurised air is blown into the aerated space through fine-bubble aeration elements. The pressurised air supplied through the diaphragm compressors is regulated by a control unit (microprocessor control unit) through the use of which the wastewater treatment plant may work in various modes depending on the loading.
Another degree of treatment is separation, whereby the treated water is separated from the activated sludge, while the purified water is discharged to a water flow or infiltration or is recycled and the set-off activated sludge is returned to the system by re-pumping from the bottom of the feeding space to the non-aerated space or, as the case may be, the aerated space. A streamflow regulator located in the feeding space allows the use of the built-in retention space in the wastewater treatment plant in the event of abruptly inflowing wastewater, thus preventing the plant from being overloaded. As a result, conditions are created for the discharge of wastewater via leakage into ground water and the reclamation of biologically purified wastewater, as the discharged water does not clog the pores of the filtration layer of the bedrock or filtration plant.

1 – Non-aerated space with vertical flow labyrinth
2 – Aerated space
3 – Feeding space
4 – Integrated retention space
5 – Inner circulation
6 – Recirculation of sludge
7 – Fine-bubble aeration
8 – Streamflow regulation

European Union
The AT wastewater treatment plant with a built-in retention space meets the EU requirement for resistance to abruptly inflowing wastewater, thus ensuring the homogeneous operation of the residential wastewater treatment plant even in the event of an abrupt inlet of a higher volume of water (e.g. from a bath tub or washing machine). As a result, the main problem of the residential wastewater treatment plants is resolved in respect of the elutriation of activated sludge from the wastewater treatment plant upon any abrupt inflow.

Technological parameters
The quality of purified water corresponds to the requirements of Directive No. 269/2010 of the Collection of Laws of the Government of the Slovak Republic on discharges into surface and ground water.
The guaranteed and commonly achievable parameters for discharge from the wastewater treatment plant are shown in the Table:

Technical parameters: