Design and construction of Ultra Compact WWTP
Usually, town or village WWTP for plants < 10 000 PE (population equivalent ) or < 1 000 m3/d flow is designed with vertical type of secondary clarifiers instead of circular. This aloud to make bioreactor of the plant very compact . For plants of this size we ultracompact WWTP solution.
Word “ultracompact” does not mean some type of biologic wastewater treatment technology, but it means, that all WWTP chains are blocked together, and amount of electric motors is minimized.
In order to keep similar to bigger size WWTP operational costs per PE small WWTP must be maximally optimized. Another problem – small WWTP shall be able to operate without constant operator presence and shall be very simple to use, because small water utilities has lack of engineering staff. It means, that just copy regular WWTP technology and reduce it size is not the proper solution. Even compact WWTP contains a lot of electric motor equipment: mixers, recirculation pumps, rotation bridges, dewatering equipment and etc. This equipment requires electric energy supply and constant service, maintenance and operation.
In our unique ultracompact WWTP the only technologic electric equipment (except pretreatment unit ) are air blowers. For biological treatment chain we have selected so-called „VFL“ technology , developed by Lithuanian WWTP producer „August ir Ko“. The main advantage proposed ultracompact system:
- Mixing in anaerobic and anoxic zone is provided by installed vertical plates, so incoming wastewater flows upward and downward (so called vertical flow labyrinth), this movement ensures proper mixing;
- All sludge recirculation and sludge removal from secondary clarifiers is carried out by airlift pumping system, (no centrifugal pumps are used). This system is very robust and do not require often maintenance;
- Secondary clarifiers are vertical (static) type, so no moving scrapper bridge is needed
- Air blowers are the only electric motors, providing air for aeration, sludge stabilization, recirculation and sludge removal airlift pumps.
- Low energy consumption due to less amount of electric equipment;
- Very simple and stable operation process, no need for operator work place;
- WWTP is fully automated, in case of emergency operator receive alarm signal to SCADA system and SMS message.
- For sludge dewatering special membrane drainage bags are proposed : 2 bag system- 1 bag for filling the sludge, another for drainage and dewatering, when full. No electricity and hand operation is required.
- All WWTP tanks are situated inside one bioreactor – simple and easy construction;
- Plants up to 150 m3/d are proposed with plastic prefabricated tanks and prefabricated container type pretreatment building.
