Ultrasonic components in water treatment

Unlike conventional processes currently used, ultrasonic is particularly environmentally-friendly due to the absence of potentially harmful chemical agents, such as methanol. Similarly, it offers superior performance when disinfecting water with high levels of turbidity, while traditional methods such as UV or chlorine are ineffective in such cases.

Central to the purification process are high-power transducers made from Morgan’s proprietary range of PZT8 ceramics. Drawing on its industry leading expertise in specially-engineered ceramic materials, Morgan ceramic rings, originally used in welding and other high power applications, have for the first time been incorporated into ultrasonic transducers used in water treatment applications.

This latest innovation offers a range of performance advantages including high permittivity, low dielectric losses, high density, high piezoelectric activity and a high mechanical factor. Available in a range of sizes with a maximum diameter of 65mm (2.6inches), Morgan rings exceed the maximum width of ceramic rings currently on the market, allowing for the application of a greater volume of power, in some instances as high as 3kW.

In aqueous media, ultrasonic waves cause periodic compression and extension of the water molecules, resulting in the formation of microscopic voids in the liquid. Such voids become bubbles of water vapour or gas and expand to the point of implosion. Large cavitation bubbles are typically produced from a range of 20 to 100kHz, depending on the viscosity of sludge and therefore the level of force required, creating high mechanical shear forces capable of destroying even the most robust surfaces. Furthermore, sonication causes a reduction of the viscosity of the fermenter content, reducing the power consumption of the agitators and pumps used in the purification process.

Frédéric Pimparel, Technical Application Manager at Morgan Advanced Materials, explained: “This latest development in wastewater treatment technology would not have been possible without the application of Morgan's world-leading expertise in specialised materials. Our ceramic materials boast a range of properties which make them ideal for use in water treatment applications, optimising the purification process while negating any adverse side effects for the environment.”