A: In the field of chemical analysis, gas washing typically involves bubbling gas through a washing bottle filled with liquid to remove impurities soluble in the liquid or to remove or convert specific components through reaction with the liquid. In aquaculture, aeration increases the dissolved oxygen levels in the water. In wastewater treatment, the purpose of aeration is to prevent solids from settling in the tank, enhancing contact between organic matter, microorganisms, and dissolved oxygen, thus ensuring the oxidation and decomposition of organic pollutants by microorganisms under sufficient oxygen conditions.

Both aeration and gas washing usually require the exhaust tube to be submerged below the liquid surface to achieve optimal results. Therefore, this application requires an air pump capable of delivering positive pressure. Depending on the required flow rate, our series of combined pressure/vacuum pumps, such as the D15, D23, D35, D50, D60 models, are most suitable.

When selecting a pump, it’s crucial to consider the water pressure at the exhaust port (Pump Output Pressure = Actual Required Pressure + Water Pressure). The water pressure is determined by the depth of the gas outlet below the liquid surface; the deeper the outlet, the higher the output pressure required from the pump. When the pump’s output pressure equals the water pressure, the pump will deliver zero flow, as the flow rate decreases with increasing pressure.