Municipal
Aerated
lagoon
In 1993, the municipality of La Guadeloupe had to increase the aeration capacity of its wastewater treatment plant due to organic overloads generated from a local industry.
Our wastewater treatment plant consist of aerated lagoons originally equipped with AtaraTM static aerators manufactured by Eco Process & Equipment Intl inc. In order to fulfil the additionnal oxygenation demand, it was decided to install floating directional aerators also manufactured by Eco Process. Four ten (10) H.P. OxyJet/AspirecoTM floating aerators equipped with KSB submersible jet pumps were selected and installed.
Since tha last six (6) years, these aerators have been operating to our entire satisfaction without maintenance problems nor other operational problems such as fouling or clogging of the mechanical elements even if no sceening is provided at the headwork end of the plant. These units have fulfilled the new oxygen requirement on a year round basis including during the winter season without being affected by the presence of ice from the surface of the lagoons. The mechanical equipment keeps on operating perfectly under a thick layer of ice that forms particularly in the last lagoon. During the cold season, the defrost system is very effective and get rid in a few minutes only of any ice blocking the air intake pipe of the ejector. These floating aerators are also quite stable, resisting to all forces exerted by the ice, wind etc...
Our experience with this type of equipment has been positive all these years. Therefore, we would honestly recommend it to other Municipalities also equipped with aerated lagoons or having problems with other types of surface aerators that would not be as well adapted for this service.
Clermont Boulanger, Municipal Inspector
MUNICIPALITY OPERATING AN OXYJET™
AERATION SYSTEM
The Municipality of St.Sophie offers water and wastewater services to a population of 500 inhabitants, also it serves a school of 750 students as well as few industries mainly specialized in food process. The wastewater is collected in the municipal sewer network and is directed to our sewage treatment plant, which was built in 1985. This plant consists of an aerated lagoon system.
Originally, our lagoons had been provided with lead-weighted polyethylene aeration piping laid in the bottom of the lagoons and fed by air blowers. This system had to be abandoned after only a few years of operation (1988) due to on-going blockage problems of its slits openings for air diffusion.
At this time, a first ten (10) HP Aspireco/OxyJet™ floating aerator was installed in the first cell. This unit is based on directional mixing and aeration and provided sufficient capacity to fulfil the oxygenation requirements throughout the entire lagoon.
In 1993, our WWTP facility had to be expanded to accept additional loads generated by regional industries. Because of our previous good experience with the OxiJet™ aerator, the Municipality selected to equip the other lagoons with four (4) additional aerators of the same brand.
We are still satisfied with the operation of our aerators. The general concept is well adapted to our nordic climate. The equipment remains reliable all year round even during the winter season while a heavy layer of ice develops on the surface of the lagoons. During this season, the floatation of the surface aerators remains stable while the defrost system protects the air intake pipe from ice formation in case of power failure. The humidity and overheat sensors installed in the pump motor are also well-adapted to this type of aerator and decrease significantly the maintenance requirement, which is no more than one inspection of the jet pump every six months as recommended by the manufacturer.
The General Director,
Eric Gagnon, CMA
