How Nanobubble Aeration Manages Sedimentation in Dams
Traditional methods to remove sediments involve costly equipment and labour-intensive solutions that, although effective, have drawbacks. Harmful chemicals and ecosystem disruption can cause more harm than good. Over the last twenty years, nanobubble aeration has developed to bypass these limitations, remove sediment, and thoroughly protect living organisms.
Sediment management is crucial for ensuring clear water in dams and other large bodies of water. Discover more about sedimentation in dams and how nanobubble technology successfully manages it.
What is Sediment?
Sedimentation refers to organic matter like sand and algae building up at the bottom layer of dams and reservoirs. Although it happens naturally, too much causes issues such as oxygen depletion and poor water quality.
What Causes Sedimentation in Dams?
When organic particles like sand settle on the bottom of a dam, sedimentation occurs. Numerous factors play into this process, which affects the amount of sediment accumulated over a certain period. The more sediment builds up, the more it disrupts the water quality.
Soil Erosion and Runoff
Water runoff from surrounding land carries soil into the dam. During heavy rainfall events, the amount of soil can impact the dam’s storage capacity. The roots of native vegetation act as a natural erosion control method; however, with deforestation, these roots are removed, and the soil’s structure falls.
Water Movement
The speed and flow in which water flows into a dam determine how much sediment is carried. Fast-flowing rivers carry a lot of large particles in a suspended state, but once they settle into a dam, they sink to the bottom and become deposited sediments.
Organic Decay
Fish, algae, and plants are among the many organisms in dams and reservoirs. When they die, their particles contribute to sediment deposition and consume oxygen, making living conditions difficult for aquatic life.
The Effects of Dam and Reservoir Sedimentation
To combat accumulated sediment, aeration is used to increase oxygen levels to boost aerobic microbial activity. These bacteria decompose organic materials, helping reduce sediment buildup, but they need enough oxygen to do so.
However, when too much sediment builds up, oxygen levels in the bottom layers drop, creating conditions that prevent these bacteria from functioning.
Without oxygen, these bacteria can no longer function, and sediment management spirals out of control as it continues to accumulate. This leads to harmful gases like hydrogen sulphide to be released, further deteriorating water quality.
Can Sedimentation in Dams Be Prevented?
As sedimentation results from the movement of river sediment, natural sediments, and solid particles carried by annual runoff, we need to look at erosion control.
Reforestation can create a buffer between loose soil and the dam to stabilise the area and prevent erosion. As well as this, check dams installed upstream help capture sedimentary rock, soil, and other material from falling into the main body of water.
How Nanobubble Aeration Works
The solution to sediment-laden water lies in nanobubbles–extremely small bubbles, invisible to the naked eye with unique properties that make them highly effective for both settled and suspended sediment management.
Nanobubbles are much smaller than conventional ones, which gives them neutral buoyancy and suspends them in the water for weeks and even months.
Filled with oxygen, nanobubbles are pumped into the water using a pressurised nozzle. Unlike traditional bubbles that rise quickly to the surface and burst, nanobubbles distribute themselves throughout the water–even reaching the sediment layer at the bottom.
Nanobubbles have an 85% oxygen transfer efficiency, which surpasses other methods of dam oxygenation. As the bubbles collapse over a long period of time, this gas is passed directly into every corner of the dam.
In addition, the collapse of nanobubbles generates mild oxidative reactions that further help break down pollutants, such as hydrogen sulphide, resulting in clear water.
Using Nanobubbles for Dam Sediment Management
In addition to being cost-effective and environmentally friendly, nanobubbles are also optimised for dam sediment management in many ways.
Hardens Sediment
Over time, as nanobubbles oxygenate and promote healthy bacteria, they trap sediment to create a firmer composition. This removes sediments with a texture similar to jelly, which is more likely to disrupt water quality.
The long-term effect is reduced sedimentation, lower nutrient release, and improved water conditions, especially in areas prone to algal blooms.
Oxygenates Deep Layers
Dam and reservoir sedimentation are particularly tricky to reach as aeration systems struggle to reach such low levels. However, nanobubbles penetrate the deep sediment layers, preventing further growth and the release of gases like hydrogen sulphide.
Increases Water Capacity
If left unchecked, too much sediment deposition reduces dam and reservoir volume, decreasing a dam’s ability to store water for irrigation or flood control. This problem worsens in large dams where sediment load is consistently high, often requiring extensive intervention.
Nanobubbles keep sediment yield within manageable levels to allow for optimal dam performance for long-lasting effectiveness. The overall lifespan of the dam is extended and the water it holds is healthy, clear, and odourless.
Improves Water Quality
It’s paramount that dam water quality is clean for both aquatic and human health. Nanobubbles continuously supply dissolved oxygen, creating an optimal environment for the dam’s whole ecosystem in just a few weeks.
Clear water free from both thick and fine sediment enhances the aesthetics of dams and reservoirs.