Traidenis - Model NV Type - Biological Wastewater Treatment Plant
NV type biological treatment facilities of domestic wastewater, sold in Lithuania, Poland, Russia, Macedonia, have been produced since 1996. NV type aerobic plants are most often used for treatment of domestic wastewater for private houses. Equipment is installed, where there is no possibility of connection to centralised sewage networks. NV type biological treatment plants of domestic wastewater are intended for treatment of domestic or similar wastewater from the kitchen, bathroom, toilet and other similar-purpose facilities.
Substances that cannot enter the treatment plant are as follows:
- surface wastewater (off the roof, from the yard, etc.);
- wastewater from a garage and other non-domestic – purpose facilities;
- water from a basin or other receptacles that are larger than 1m3;
- chemical substances, entering into sewage system of which is not provided according to their usage (oil products, agrochemical substances, etc.);
- water after regeneration of filters of softening/removal of iron;
- chemicals used at home (washing means, bleaches, softeners, degreasers) shall be use as provided in manufacturer’s recommendations.
- factory enclosed biological treatment unit for domestic waste;
- various capacities;
- high level of treatment, removed 95–98% of pollutants;
- no internal movable parts to be supervised or replaced;
- serviceable, light-weight glass-fibre structure (easy transportation);
- quiet operation and no offensive odour diffusion;
- treated discharged water – transparent and odourless;
- minimum power consumption;
- no need in auxiliary filtering equipment;
- easy maintenance and process automation;
- easy installation.
Treatment plant is used as an underground facility. Supplementary collection (riser rings) depends on manifold deepening. Subject to the selected place, treatment plant may be installed in a green lawn or under the roadway (not recommended due to uncomfortable maintenance).
About NV 1÷4a type wastewater treatment plants
NV 1÷4a type wastewater treatment plant consists of two chambers present in one tank (Figure 1). At first, wastewater, flowing into the plant, enters into the internal chamber, where it is mixed with the activated sludge with the help of air. Compressed air is necessary for supporting life of activated sludge and internal recirculation of treated wastewater. Air is provided with the help of the compressor (airblower). Biological treatment, i.e. treatment with activated sludge, is based on microorganisms’ activities. Purpose of the process is to bind soluble, colloidal and biogenic substances from wastewater into active sludge and separate activated sludge. Flake forming microorganisms multiply and form groups that cause adherence of protozoots and other bacteria. Microorganisms metabolyse (“eat up” and decompose) and destroy organic substances. Decomposition of organic materials and formation of the activated sludge takes place in the aeration section. Mixture of the activated sludge from the aeration chamber enters the external chamber (the secondary settling vessel), where, due to gravity forces, the activated sludge separates and falls down into the bottom part of the plant and the separated treated water lifts up and drains away. If the mass of microorganisms increases, the amount of the activated sludge also increases. Excess sludge is removed by the assenisation machine by pumping-off two-thirds of the plant capacity.
Main structural parts:
1. Body (GRP)
5. Inflow pipe
6. Outflow pipe
7. Air inlet pipe
9. Riser ring
10. Box for airblower