A
solar-powered circulator technology, named SolarBee was developed
in the US in 2001, to solve serious water quality and energy problems
in fresh water lakes, wastewater lagoons, storm water ponds, estuaries,
potable water storage tanks and other reservoirs.
The
SolarBee's high flow mixing action accelerates the normal purification
process in the pond through gentle, thorough mixing and surface
re-aeration.
Applications:
Lakes
and Ponds
Blue-green
algae blooms (BGAB's), degrade water quality in terms of taste,
odour, aesthetics, and health of the food chain. Recent testing
indicates BGAB's create potent toxins which could lead to
health problems in humans and animals. Eliminating these BGAB's
leads to increased operating costs of drinking water treatment
plants and as more lakes are closed due to these health risks,
there will likely be a strong negative impact on the recreation
industry, the travel industry, and lakeside property values.
Standard methods of treating BGAB's such as alum applications,
aeration, hypolimnetic aeration, hypolimnetic oxygenation, bottom
release, drawdown, dredging, top-down strategies such as poisoning
all of the fish in a lake, calcium additions, and others have
proven to be ineffective. Although Algae poisons can give short-term
relief from BGAB's, they have many harmful immediate effects
and may create serious long-term toxicity issues.
Rather than trying to limit overall algal growth through reductions
in nutrient availability, SolarBee circulation prevents blooms
of blue green algae through habitat disturbance. This form of
manipulation selects against bloom forming blue green while
favouring non blue green species. Extensive studies have shown
significant biological benefits to water bodies when blue green
algae are repressed.
Wastewater
Lagoons and Ponds
Solar-powered
circulators reduce aeration run-time while maintaining or
improving the water quality. Aeration systems are sized by
considering both (a) the horsepower needed for oxygen production,
and (b) the horsepower needed to mix the oxygen throughout
the pond. The larger figure, usually the mixing horsepower,
is installed. Solar powered circulators can supply most of
the mixing energy, thus reducing the hours that the aeration
system needs to be operated. Solar powered circulators also
increase odour control and reduce biosolid volume at the bottom
of the pond or basin, thus reducing costs to dredge and dispose
of the biosolids.
Stormwater
Ponds
Most
storm water ponds do not have access to grid power and are
perfectly suited to solar powered circulators, which can provide
odour control, improved reduction of biochemical oxygen demand
(BOD), improved water aesthetics, and prevention of BGAB's
which otherwise would create more BGAB's in downstream lakes
and reservoirs.
Estuaries
Solar-powered
circulators have the potential to clean up and reverse huge
environmental problems in estuaries, including very large
bay systems.
Potable
Water Storage Reservoirs.
After
drinking water has been treated with chlorine or chloramine,
it will typically flow through storage reservoirs or water
tanks or water towers in the distribution system. The water
in these reservoirs can become stagnant and develop a long
water age, leading to loss of disinfection, and/or the formation
of nitrates, taste, and odour. Solar-powered circulators can
be put inside the tanks, with the solar modules on top of
the tank, to keep the water fresh.
There
are four sizes in the SolarBee range varying in capacity from
five hectare to 18 hectare coverage. Depending on the size and
underwater options fitted these upflow units can effectively draw
water from depths varying from 0.6 to 30 metres.
The
first installation of a SolarBee unit in Australia was in Nhulunbuy
NT in 2005. Reports from the site speak of a significant improvement
in the stored water quality.
Nhulunbuy
installation: The SolarBee unit was installed in the lagoon in
the background where the
mixing action can be clearly seen across the surface of the water.
