How to solve the problem of foam accumulation in Vortex Dissolved Air Flotation

To address the issue of foam accumulation in Vortex Dissolved Air Flotation (VDAF) systems, several effective strategies can be employed.

One approach is to adjust the operating parameters. Firstly, optimizing the air - water ratio is crucial. Excessive air injection can lead to an over - generation of bubbles, causing foam to accumulate. By carefully calibrating the air compressor and regulating the air flow rate, the formation of excessive foam can be minimized. Additionally, controlling the influent flow rate and the rotational speed of the vortex generator is important. A stable and appropriate flow rate ensures that the bubbles are evenly distributed and properly interact with the suspended solids, reducing the tendency for foam to build up.

Another solution is the use of anti - foaming agents. Chemical anti - foaming agents can be added to the influent or directly into the flotation tank. These agents work by breaking down the surface tension of the foam, causing it to collapse. However, it is essential to select anti - foaming agents that are compatible with the wastewater characteristics and do not interfere with the overall flotation process. Conducting small - scale tests beforehand can help determine the most suitable type and dosage of the anti - foaming agent.

Regular cleaning and maintenance of the VDAF system also play a significant role. Accumulated foam and sludge can adhere to the tank walls, baffles, and other components, promoting further foam generation. Periodic removal of these deposits using mechanical scrapers or high - pressure water jets can prevent the buildup of foam - promoting substances. Additionally, checking and cleaning the air - release nozzles regularly ensures that the bubbles are uniformly sized and properly released, reducing the formation of unstable foam.

Moreover, modifying the system design can be considered. Installing additional foam - removal devices, such as foam skimmers or baffles specifically designed to break up and remove foam, can enhance the system's ability to deal with foam accumulation. These devices can continuously remove the floating foam from the surface of the flotation tank, improving the overall operation efficiency and reducing the risk of foam overflow.