The role of liquid oxygen in sewage treatment

First, the role of aeration grit tank

   (1) Working principle of aerated grit tank: The aerated grit tank is due to aeration, which produces a swirl on the cross-section of the grit tank, and the water flow in the entire grit tank produces a spiral flow form. Inorganic sand grains are caused by centrifugal force. In a advection grit tank, by controlling the flow rate or speed of the sewage entering the grit tank, the denser inorganic particles sink, while the organic particles are carried away with the water flow.

   (2) The role of liquid oxygen in the aerated grit tank: There is a row of air diffusers on the wall on the side of the aerated grit tank. By introducing liquid oxygen, the sewage can flow in a spiral shape, and the gravel in the sewage can be taken to the sand collection tank at the bottom of the grit tank for separation. From long-term operation practice, it has been proved that the aeration grit tank can remove fine sand particles with a particle size of less than 0.6 mm, and only a small amount of organic matter is contained in the grit tank.

       Long-term experiments have shown that compared with air aeration, oxygen aeration has a much higher oxygen filling than air aeration at the same energy consumption.

Second, the role in the activated sludge method

       Working principle of activated sludge method: activated sludge method is an aerobic biological treatment method for sewage, which is one of the widely used sewage treatment methods. The activated sludge method consists of an aeration tank, a sedimentation tank, a sludge reflux and a residual sludge removal system. The main processes are mechanical grid, precipitation, aeration, secondary precipitation, etc. Among them, the aeration process is the core part of the activated sludge method.

       Three basic elements constitute the activated sludge method: First, microorganisms that cause adsorption and oxidation, that is, the activated sludge method. The second is the organic matter in the wastewater, which is the object of treatment and the food of microorganisms. The third is dissolved oxygen. Without sufficient dissolved oxygen, aerobic microorganisms can neither survive nor undergo oxidative decomposition.

       The role of liquid oxygen in the activated sludge process: a large number of microorganisms in the sludge use sewage as nutrients to convert pollutants into CO2 and H2O under the action of active oxygen. When the oxygen content in sewage is lower than a certain value, if it is lower than 2mg/L, the activity and action value of microorganisms will be significantly reduced. If the oxygen content is further reduced, the microorganisms die and the activated sludge loses its ability to purify. Therefore, trying to increase the oxygen content of the aeration tank has become the key to the activated sludge method, and the input of liquid oxygen can provide the oxygen concentration required by the activated sludge aeration tank.

       The role of liquid oxygen in aeration biological filter: mainly the aeration link in the entire filtration system, providing high concentration oxygen through liquid oxygen, and directly infiltrating into the biofilm through backwashing oxygen to achieve biochemical reactions and effectively retain water. Suspended solids and newly formed biosolids.