The core of water treatment defoamer

The Core Functions of Water Treatment Defoamers

• Foam formation arises from the accumulation of surfactants in water, which form stable bubble films by reducing surface tension. The mechanism of action of defoamers effectively addresses this weakness:
• Foam-breaking: Water treatment defoamers adsorb onto the foam surface, reducing local surface tension and rapidly rupturing the bubble film. For example, silicone-based water treatment defoamers use emulsification and dispersion technology to evenly coat the bubble surface with silica particles, destabilizing them.
• Foam-inhibiting: By modifying the surface properties of the liquid, they inhibit the formation of new foam. For example, in activated sludge biological treatment, surfactants produced by microbial metabolism can easily trigger foaming. Defoamers can intervene early to reduce foam accumulation.
• Deaeration: Bubbles are encouraged to coalesce into large bubbles that rise quickly to the liquid surface and then burst, reducing foam accumulation in the system. This is particularly critical in the treatment of oil drilling fluids, preventing foam from clogging pipes.

 Performance Testing of Water Treatment Defoamers

The performance of defoamers directly impacts water treatment effectiveness, so their effectiveness must be verified through standardized testing. The following are several mainstream testing methods:

• Spray Test: This simulates actual operating conditions by spraying a bubble solution to generate foam. After adding a defoamer, the time it takes for the foam to dissipate is recorded. For example, at a constant temperature of 25°C, 0.2g of defoamer is added to 50ml of the foaming solution, shaken, and the rate of foam dissipation is observed.
• High-Speed Stirring Test: Suitable for high-viscosity systems, the sample is stirred at 3000-6000 rpm in a stirrer, and the change in foam volume is recorded.
• Circulating Pump Test: This involves circulating a bubble solution in a closed loop. After adding a water treatment defoamer, the foam height is continuously monitored. This method can evaluate the durability of water treatment defoamers under dynamic operating conditions.
• Storage Stability Test: This involves placing the water treatment defoamer in a constant-temperature oven at 50°C for two weeks, simulating the effects of six months of aging at room temperature, and measuring its performance degradation rate.