Innovative anaerobic submerged media in small waste treatment plants in Hungary
Abstract
During the past 10 years 32 anaerobic FLEXIPAK®-MINI waste water treatment plants were installed in Hungary, all in unique, energy saving communal areas without public sewer systems. Innovative research and development, as well as planning were carried out by GYULAVÁRI CONSULTING Ltd. (Gyulavári & Kormos, 1993).
Using the TURBOPAK® contact units developed by our company, the anaerobic treatment process has provided phase separation (removal of suspended solids) and biological partial treatment at the same time, ensured partly by the sloping, 60º angle installation of the units, generating a gravitational upward flow. The multi cell contact unit provides a 150 m 2 /m 3 specific anaerobic biofilm surface for the microorganisms.
Based on our experience with combined dual processes, the TURBOPAK® contact unit provides an innovative, efficient and cost effective solution for intensification, compared to formerly known anaerobic, energy free solutions. The new innovative equipment was registered under the FLEXIPAK®-MINI brand name and the manufacturer of TURBOPAK® (System Gyulavári) is PANDAN Ltd. (Hungary).
Keywords
Download Options
Introduction
The lack of a central sewer system near or outside city limits and in certain rural areas, such as farms, it is a global need and task to solve the treatment of waste water and develop sewer systems (Boumai, 1975). It is an additional requirement for these solutions to be small scale, as far as possible without the need for outside energy, simple operation and the possibility of the treated water to be ready for reuse, such as for surface or general irrigation. Another requirement is for the treatment process to be constantly efficient, low noise and without generating large quantities of sludge, etc. (Jewel et al., 1975; Otis & Boyle, 1976).
Besides these advantages, another requirement is to have a large enough area nearby for placing, settling the treated water. For a good settling process "porous" soil layers are needed, preferably with adequate, maximum ground water levels (Jones & Tayler, 1965; Pradhan et al., 2011¸ Veres et al., 2015). The above listed advantageous conditions are not available in every country, but in most cases can be created as realistic or necessary solutions.
One of the solutions for general needs, for plants serving 5-20 people for example, is an anaerobic settling system widely used in the USA as a pretreatment solution installed before septic tanks, where waste is treated for approximately three days, and which does not require added energy and satisfies all requirements (Bouma, 1975).
An additional benefit of this solution is that it can be used intermittently and for periodically changing loads. According to related literature, approximately 19.5 million such systems were used within the USA in 1970 which meant that 30 % of the population applied this supplementary method in combination with other solutions. This is a realistic overview of the present situation within the USA (Otis & Boyle 1976).
Conclusion
By implementing several modern developments FLEXIPAK®-MINI provides various benefits over similar traditional anaerobic equipment.
By implementing the recommended developments total times spent in the system can be reduced to 2-2,5 days.
Sludge needs to be hauled away only every 1.5 to 2 years.
The elimination of unpleasant odors is more efficient, so the setup can be installed as close as 6-8 meters to residential buildings.
The plant can be installed either over or under ground.
The shape of the installation can be either circular or rectangular.
The setup can be built from different materials, such as steel, reinforced concrete or plastic, but it must be corrosion resisting.
They are generally prefabricated and assembled and installed on site. In case of a circular installation diameters can vary between a minimum of 1.0 meter, and up to 1.3, 1.85 and even 2 meters.
Based on the anaerobic Dual-Biological Process (DBP) energy free operation is available for each installation alternative.
We use the TURBOPAK® fix submerged biological contact units for each installation, where a total of 150 m2/m3 specific anaerobic biofilm surface is provided.
The guaranteed lifetime of the poly-propilene (PP) plastic cylinder shaped FLEXIPAK®-MINI tank reactor is 25-30 years.
The plant ensured increased treatment efficiency, especially for decreasing suspended solids (SS) content, which constitutes an important benefit and ensures longer lifetimes in cases where water is bled into porous soil layers.
Maintenance needs are minimal; it does not contain any turning parts. It is failsafe.
In case of technical or power outages the system stays in operation.
In case of existing anaerobic systems, such as overloaded septic tanks, it can be used as an additional polishing phase.
Based on results in communal areas the system can be deemed successful for treating waste water with organic pollutants.
Further development, reviews and research is recommended.