Phosphorus removing method from waste water and preparation method of ferrous phosphate

Abstract

The invention provides a phosphorus removing method from waste water. The method includes following steps: providing a solution containing phosphate anion; mixing a solution containing ferrous ions and the solution containing the phosphate ion and performing fluidized bed crystallization to obtian a ferrous phosphate precipitation, wherein a pH value of the fluidized bed crystallization is 5-6 and a molar ratio of the ferrous ion to the phosphate ion is 1.5-2.5 and a volume ratio of the solution containing ferrous ions to the solution containing the phosphate ion is 10-20; and removing the ferrous phosphate precipitation. The invention also provides a preparation method of ferrous phosphate. By means of the phosphorus removing method, damage of the waste water to environment can be reduced and meanwhile economic benefit is achieved. By means of the preparation method of the ferrous phosphate, the ferrous phosphate being low in water content, being high in purity and being high in crystallization rate can be prepared.

Description

technical field [0001] The invention relates to a method for removing phosphorus from wastewater and a method for preparing ferrous phosphate, and in particular to a method for removing phosphorus from wastewater with a solution containing ferrous ions by using a fluidized bed crystallization reaction and the method for using ferrous phosphate Method for the preparation of iron. Background technique [0002] Phosphorus is an indispensable element in agriculture and industry, but phosphorus-containing wastewater usually causes eutrophication and causes serious harm to the environment. Phosphorus-containing wastewater generally refers to a solution that includes phosphate ions. In the current technology, chemical coagulation method, calcium hydrogen phosphate fluidized bed crystallization method, etc. are generally used to treat phosphorus-containing wastewater, in order to remove phosphate ions in phosphorus-containing wastewater. [0003] In general, chemical coagulation i...

AI Technical Summary

Problems solved by technology

Although this method can effectively reduce the CaCl 2 The amount of dosing and solve the problem of the amount of sludge in the chemical coagulation method, but because the concentration of phosphate ions in the inflow is easy to change, it is not easy to control the metastable zone, so it is easy to form scale on the tank wall and pipe wall, lead to blockage of the pipeline in the reaction tank

In addition, neither the chemical coagulation method nor the calcium hydrogen phosphate fluidized bed crystallization method can obtain phosphorus-containing products with a high crystallization rate.

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