Algae control in drinking water reservoirs - Water and Wastewater - Drinking Water

Treating algae in drinking water with ultrasound reduces taste and odour problems without harming the ecosystem. Prevent the occurrence of toxic blue-green algae. Reduce chemical dosage. Products can be NSF/ANSI Standard certified.

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Excessive cyanobacteria (blue-green algae) and green algae growth in a water reservoir for drinking water can have negative consequences for the water quality.

The water turns green, sand filters can clog, and some algae can produce geosmins and MIB- giving the water an ‘earthy’ and ‘molty’ taste, which can result in customer complaints. In addition, cyanobacteria may produce toxins that can cause serious illness in humans consuming the water. Therefore, an algae problem is often unwanted, and algae control is desired.

In drinking water reservoirs and other water bodies algae growth can occur. Algae cells need light, water, carbon dioxide and nutrients, which are naturally occurring in water, in order to grow. An algal bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. Excessive algal growth can result in the occurrence of several algae related by-products, such as toxins, MIB, and geosmins. These by-products can have a serious impact on the water quality. Nutrient buildup in a lake or reservoir can be due to irrigational run-off, pollution from industries, and a general build-up of organic material at the bottom of the lake or reservoir.

Especially in the summer months, when the water temperature increases, the concentration of algae can grow exponentially. Water in raw water reservoir is often stagnant, the lack of circulation of the water can cause the algae to over-compete other organisms in the ecosystem and thus create massive algae blooms. In order to deal with these by-products, water treatment plant (WTP) operators often use copper sulfate in a raw reservoir to control the algae. Additionally, Activated Carbon filters are used to remove geosmins, MIB, and Toxins from the final product. Removing algae from the water treatment plant is expensive and time consuming (e.g., the removal and cleaning of the sand filters).