WWTP

BIOLOGICAL WASTEWATER TREATMENT PLANTS FEL 4÷25

Wastewater treatment plants (WWTP) are installed in areas where connection to the central sewer system is impossible. The equipments are intended for treatment of domestic wastewater from toilets, bathrooms, kitchens and other similar household premises. The equipment cannot collect surface wastewater such as rooftops, garden yards, rain and drain water. It cannot collect wastewater from garages and other non-living premises, from swimming pools or other large tanks. Equipment cannot collect oil and other petroleum products, grease, chemical substances, which access the sewage is not foreseen according to their scope (agro chemistry, bleach and other chemical substances). The treated wastewater may be safely released into the surface waters or into the ground (through the filtration field or ground water catchment). Also it may be directed into the meliorative ditches, on the roadsides. Also it may be used for secondary use.

WWTP FEL 4÷25 OPERATION

The equipment does not require special operation. It is enough to eliminate 1-4 times a year the surplus sludge which has collected in a bottom of secondary settler. It is necessary to disconnect and remove the air blower pipe. The surplus sludge is sucked through the vertical pipe. That sludge which remains on bioload after the elimination is sufficient for normal functioning of the equipment. Also other preventive checks, such as the work of the air blower, check if the air filter is clean, check of aeration system are necessary, etc. Interval between preventive checks may reach from 1 to 4 times per month.

Air blower – The air blower has to be installed in a dry and well ventilated room. The blower should not touch the wall. Also the blower cannot be installed in living premises or in the places that are allocated carbon dioxide (e.g. garage). In case, when the air blower is installed outside, it should be protected from a rain, a dust and humidity. In this case the air blower has to be placed in the special fibreglass box. The air blower should work constantly and it should be connected to the electricity system. Also it is necessary regularly to check its work (whether it heats up, whether there was vibration etc.). More operation and maintenance information is described in the air blower instruction. It is necessary to read the air blower operation and maintenance instruction.

WWTP FEL 4÷25 ADVANTAGES

• High polluting substances cleaning;
• Durable light plastic construction (easy to ship);
• Treated wastewater is clear and odorless;
• No need in additional filtering equipment;
• Quiet and does not diffuse smell;
• No moving parts inside which would require maintenance or replacement.

PRINCIPLE OF WWTP FEL 4÷25 OPERATION

The equipment comprises of two centered cylindrical tanks with conical bottoms; the inner part is the aerial zone (air tank), the outer part is the secondary settler.

Air tank – There is a vertical pipe fitted with diffuser in the centre of it. Feeding the compressed air from the air blower to the diffuser, the heavy activated sludge is sucked from the secondary settler and the sludge mixture is sucked from aerial zone. In this way, the circulating flow is formed in aerial zone. This allows oxidizing organic pollutions not only by the activated sludge in sinking condition, but also by the bio-film, formed on the bio-load. Furthermore, as the circulating flow goes down, the concentration of the dissolved oxygen decreases, thus in the upper layers of bio-film develop not only the processes of decomposition of organic pollutions, but also the processes of nitrification (ammoniac nitrogen oxygenation up to nitrates), and in the lower layers, due to shortage of the dissolved oxygen, develop processes of denitrification (oxygen consumption from nitrates and nitrites). Thus the removal of total nitrogen is no less than 50%; in equipment with standard system of the activated sludge the concentration of nitrogen reduces only by 20%. Therefore, the bio-load allows preventing the impact of denitrification (emerging of sludge) in the secondary settler.

Secondary settler  – The mixture of the activated sludge from the aerial zone gets into the conical part of the secondary settler, where there is the settled and the compacted activated sludge. During the filtration of the sludge mixture through the compressed sludge, minor sludge flakes are also restrained, thus a lower concentration of sinking materials is ensured in the treated waste water. The treated waste water is collected into the peripheral chute. In order to maintain an even load of the chute edge, an adjusted pectinated edge is attached to the chute. The waste water is removed from the chute by the outlet pipe. Some activated sludge may periodically rise to the top of the settler. A baffle is fitted and plunged, in order to withhold it from entering the treated waste water. When the concentration of the activated sludge in sinking condition increases up to 6 g/l, the surplus sludge is sucked through the pipe of the aerial zone.

PARAMETERS OF WWTP

Specification

1 – pectinated edge; 2 – the collection duct of the treated wastewater; 3 – air tank; 4 – bio-load; 5 – directable flow pipe; 6 – half-plunged baffle; 7 – secondary settler; 8 – air supply pipe; 9 – diffuser; 10 – air blower

TECHNICAL DATA OF WWTP FEL 4÷25

CLEANING EFFICIENCY

WWTP FEL 4÷25 meet all norms and regulations, is technically approved, measured and controlled based on the European standard EN 12566-3. Equipments meet the requirements of EU directives for electrical and construction products № 2006/95/EC, 2004/108/EC and 89/106/EEC, and correspond to the characteristics and rules specified in Annex ΖΑ of European standard ЕΝ 12566-3+A1:2009 "Small wastewater treatment plants for up to 50 PT. Part 3. Packed or/and site assembled domestic wastewater treatment plants”. WWTP FEL 4÷25 was tested in Engineering Test Institute (Notified Body 1015) in Brno (Czech Republic). On 14th of December 2009 Engineering Test Institute issued Certificates, which allow to issue EU Declaration of Conformity and give the right to mark WWTP FEL 4÷25 with CE mark. Annual average treatment efficiency ratios according to BOD5 – 98%, COD – 93%, SS – 94%. In 2009 FEL type WWTP has been granted a design patent No. 1618.