The oases of the future

Tony Wynes reveals why it is imperative to create innovative systems that improve water quality.

“All life on the planet ceases without clean water”

If a lake or enclosed seawater has negligible through flow of water, an unmixed and heavily stratified water body is created. Numerous reports show that these water bodies have low dissolved oxygen (DO) in the deeper waters (8m+) and often toxic blue green algal blooms. This low DO, coupled with a high temperature drop through the water column, means that the water body will be struggling to support fish, aquatic flora and fauna.

Thermal stratification in water bodies is caused by heating the surface waters. As convection is the major method of heat transfer within a water body, hot water rises and cool sinks, thus it is unable to mix. This leaves a very warm top layer (epilimnion), a cold bottom layer (hypolimnion) and the transition layer (thermocline or metalimnion). As plants require light for photosynthesis, which creates oxygen, this leaves the epilimnion with plentiful oxygen, but the hypolimnion with very little or no oxygen and no way to mix the two layers.

Waterbodies worldwide suffer with significant increases in concentration of manganese (Mn) and iron (Fe) in the water column in the summer. Academics attribute this to anoxic bottom water caused by the onset of thermal stratification. Together with a lowering of pH, certain bacteria are thought to contribute to these elements release from bottom sediments.

Algal blooms, caused by an increased concentration of algae in the surface waters, are unsightly and possibly toxic. They require sunlight and nutrients to survive in large numbers. If they become too large, sunlight to the bottom water is cut off, depriving the plants of the ability to photosynthesise. This decreases the oxygen levels in the bottom waters, killing the aquatic life living there, which in turn increases the amount of bacteria needed to break down the food and further decreases the oxygen concentration in the bottom waters. The cycle continues until there is no marine life left in the waterbody except algae and bacteria.

AMG has spent 38 years innovating systems that improve the quality of water in reservoirs and the sea. Our cutting edge 'Aquaerator' has no moving parts and is the scientifically proved answer to many waterbody problems, particularly stratification and oxygen deficiency causing metals in suspension. Unfortunately few people realise that bed water is a higher density than surface water. Thus it is vital to place aeration and mixing devices on the bed, using a simple principle. It takes more energy and costs more to force air down from the surface, whereas a bubble plume from the bed rises naturally towards the surface. Our EU financed technology, creates a highly turbulent rotating bubble plume of water/air, causing considerable additional entrainment whilst rising. It produces a surface plume flow of 4.5tons/sec from 10m depth or 13.4tons/sec from 20m in reservoirs.

Municipal wastewater treatment is vital to improve the quality of life of the whole population and for increasing the overall water available for recycling. Existing wastewater technology has a high carbon footprint due to the electricity used to recycle it.  Thus we have designed an Aquaerator that will prove more energy efficient by using less electricity. Another asset is that it is easy to move from the bed for cleaning and replacement without the major cost of emptying the main operating tank. 

Each state or country must create environmental management plans for water and wastewater to determine total water requirement for personal consumption and the growing of food crops taking climate change into account. These should identify the most energy efficient systems to ensure the lowest carbon footprint. I hope each region will build reservoirs, lakes and dams on rivers to store the most vital commodity for the continuation of human life, water. Trees can surround water bodies to reduce the effect of climate change and sandstorms to form the oases for future generations.

Having commanded Royal Navy Minesweepers, Tony Wynes set up Aquarius Marine Group Ltd 37 years ago as a diving maintenance and environmental consultancy. This led him to invent and coordinate the design of the 'Aquaerator', which is patented in many countries around the world.