With the development trend of social economy, environmental pollution has attracted more and more attention. Sludge disposal has become a difficulty in wastewater treatment in processing plants. There are various types of dosing devices, and sludge dosing device is one of them. Let's take a look at the correct treatment of phosphate in the dosing device of dosing metering pump.
1. Phosphate solution
The method is to add phosphate brine solution under the standard that the boiler water is slightly alkaline, so as to maintain the phosphate radical in the boiler water within the concentration range, the sodium ion and phosphate radical in the water are reflected and transformed into slightly alkaline calcium carbonate, and a small amount of aluminum ion and aluminosilicate in the boiler water produce serpentine. Alkaline calcium carbonate and serpentinite are insoluble chemicals, which are dispersed in boiler water and softened water slag. They are very easy to be discharged from the boiler and are not easy to adhere to the heated surface of secondary fish scales.
2. "Temporary disappearance" of phosphate in boiler water
When the amount of phosphate sludge in some boilers is normal, when the boiler operation load increases, the phosphate concentration in the boiler water will be significantly reduced. When the boiler load decreases or terminates in the boiler, the phosphate concentration in the boiler water will increase again. This abnormal water condition is called phosphate "temperature". "Counterfeiting disappeared" status. The way to avoid this situation is to implement the boiler water treatment method of low phosphate solution, balanced phosphate solution, or evaporation solution. Isophosphate solution can not deal with the disappearance of phosphate, but can avoid alkali etching caused by the disappearance of phosphate.
3. Equal composition phosphate solution
The method is to mix the boiler water with trisodium phosphate and sodium hydrogen phosphate. There is no water in the boiler, which is transferred to trisodium phosphate and sodium hydroxide solution. Only the molar ratio (R) of potassium ion and phosphate ion in the water in the boiler (Na / PO4 is controlled within the scope, which can make the water in the boiler have sufficient pH value and concentration). Quantitative analysis of PO43 - no sodium hydroxide solution.
When equal phosphate solution is selected, phosphate is very easy to disappear and etch. In order to solve this problem, the balanced phosphate solution (EPT) method is selected.