Algae growth

Why it is important to control algae growth

A combination of high temperatures, stagnant water and nutrient overload can result in excessive algae growth.

These so-called algal blooms can lead to a depletion of oxygen in the water, release of toxins and taste and odor problems. Without treatment, the algae will grow more every year, resulting in an unbalanced ecosystem. Therefore, it is important to control algae growth for a healthy ecosystem.

Algal bloom causes

Why algae are important

Algae are a diverse group of plant-like organisms that occur in a wide range of environmental habitats. They are photoautotrophic cells that contain chlorophyll, have simple reproductive structures, and their tissue is not differentiated into true roots, stems or leaves. The term “algae” covers a variety of organisms that produce oxygen using photosynthesis. It is estimated that about 70-80% of the oxygen we breathe comes from algae. Beside producing oxygen, the algae provide food for fish and other aquatic animals.

In all water bodies, a basic level of algae is present. These algal concentrations belong to the normal lake ecology and are also important for the ecological balance within the water. However, almost everywhere where water is stored, algae problems occur. When water is stagnant, has a high temperature or a high concentration of Nitrates and Phosphates, an algal bloom might occur, which can cause several problems.

When algae cause problems

When a specific algal type starts growing exponentially, it can suffocate other organisms within the water that are important for a balanced lake ecology.

This results in reduced light penetration into the water column and increased pH, which in turn leads to the reduced growth of plants and hence reduced levels of dissolved oxygen in the deeper layers of the lake. The balance within a lake shifts even more as aerobic bacteria in the soil start to die, and nutrient digestion is taken over by anaerobic bacteria, causing a deterioration of the water quality and eventually massive deaths of fish and other aquatic organisms, creating a misbalance in the lake.

Thus, several factors favour the blooming of specific algae, leading to a shift of the balance of the lake.

Algal blooms usually take place in freshwater, such as lakes and water reservoirs as well as in marine milieus. They can be easily identified by colouration of the water ensuing from the high density of pigmented cells. Though many types of algae can form blooms, cyanobacterial harmful algal blooms (CyanoHABs) have the potential to produce toxins that are dangerous to other organisms including humans, pets, and livestock.

Nutrient pollution solutions

Ultrasound as a solution to control algae

To prevent or restore an unbalanced ecosystem, it is important to control algae problems. When it comes to lakes or bigger ponds, current algae control methods include aeration, mixing and ultrasound. As an alternative for the use of chemicals, LG Sonic developed a technology based on ultrasound to effectively control algal blooms.

Controlling algae with ultrasound is a well-established technology that has existed for many years. It is an environmentally-friendly and cost-effective technology that is completely harmless to fish and plants.

How ultrasound controls algae

Controlling algae growth with low-power ultrasound is a well-established technology that has been in existence for many years. It is an environmentally-friendly technology that is harmless to fish and plants.

LG Sonic makes use of specific ultrasonic sound waves to control algal blooms. To control the algae, an LG Sonic transmitter is installed in the water that transmits specific ultrasonic sound waves. The sound waves can spread through the water column over hundreds of meters. Blue-green algae are in the possession of gas vesicles. During the day, the algae travel up and down in the water column. They travel to the water surface to absorb sunlight for photosynthesis and to the bottom for nutrients.

The ultrasonic sound waves create a sound layer in the top layer of the water which affects the buoyancy regulation of algae, fixing them in the water column.

Due to a lack of sunlight and nutrients, the algae will sink to the bottom of the reservoir where they will eventually die and decompose. However, because they are still a vital part of the water ecosystem, the ultrasonic algae control does not eliminate the algae completely but reduces them by up to 90%. This restores the water ecosystem by reducing and controlling the algae levels. In general, ultrasonic algae control does not significantly alter the basic level of algae present in a lake.

Ultrasonic algae control system

However, due to the direct effect of the ultrasound on the vertical distribution of algae in the water column, the ultrasound directly influences the capability of an algal species to form a bloom. In general, these blooms can be reduced by 70-90% in concentration, compared to no treatment.

When the algae are controlled with ultrasound, the algae levels decrease gradually; however, if no treatment is applied, the algae will grow more and more each year. When the algae levels decrease, the water clarity will improve which will result in plant growth, increased oxygen and fish growth. The ultrasonic treatment reduces algae levels by 70-90%; this is because algae are still needed in the ecosystem but in moderation. A good balance between the algae, plants and fish creates a healthy ecosystem. In this way, the ultrasonic treatment contributes to a healthy ecosystem.