Device and method for recovering phosphorus from sewage

Abstract

The invention relates to a technology and a device of environmental protection and resource recycling, and particularly relates to an induced crystallization reactor and solid-liquid separation device and a method for efficiently recovering phosphorous from the sewage. The induced crystallization reactor and solid-liquid separation device comprises a water inlet part, an agent adding part, an acidity regulating part, an aeration stirring part, an induced crystallization reaction part, a solid-liquid separation part and a crystal recovering part, wherein the induced crystallization reaction part is communicated with the solid-liquid separation part, and fully develops a seed crystal inducing function. According to the induced crystallization reactor and solid-liquid separation device and the method, phosphorus in the sewage is induced by using calcite as a seed crystal and is recovered in a hydroxyapatite (HAP) crystal manner, the recovered product can be directly applied to industry and agriculture so that sewage treatment, environmental protection and resource recycling are organically combined. In addition, the method has the characteristics of small occupation area, high recovering efficiency, good quality of the recycled product, less investment of equipment, and convenience in running and operation.

Description

technical field [0001] The invention relates to environmental protection and resource recycling technologies and devices, in particular to an induced crystallization reactor, a solid-liquid separation device and a method for efficiently recovering phosphorus from sewage. Background technique [0002] Nitrogen and phosphorus are important factors that lead to eutrophication of water bodies. According to Liebig's law of minimum factors, phosphorus is the key factor that leads to eutrophication of water bodies (C 106 h 263 o 110 N 16 P) A limiting factor for growth, many countries have strict restrictions on their emission concentrations. When the concentration of phosphorus in the water body reaches 0.015mg / L, it will cause rapid growth of algae, and every 1g of phosphorus discharged into the water body will lead to the growth of 950g (dry weight) of algae. The direct consequence of the rapid growth of algae is to accelerate the aging process of the water body, making the ...

AI Technical Summary

Problems solved by technology

The chemical precipitation methods mainly include calcium salt, iron salt, aluminum salt, magnesium ammonium phosphate (MAP) precipitation method and hydroxyl calcium phosphate (HAP) precipitation method. The disadvantage of this method is that the recovered product has poor quality, high moisture content and cannot be directly applied to actual production

In addition, sediment dewatering equipment is required, which increases operating costs

[0006] (2) Biological phosphorus removal method: This method enriches the phosphorus in the sewage in the form of phosphorus accumulation in the phosphorus removal microbial cells, and then recovers phosphorus in the form of sedimentation sludge. The disadvantage of this method is that the moisture content of the sedimentation sludge is High, and contains various forms of heavy metal compounds, difficult to recycle

In addition, this method is highly susceptible to toxic substances in wastewater, such as organophosphorus pesticide wastewater

[0007] (3) Adsorption method: This method uses adsorption materials containing phosphorus compounds such as amino groups to adsorb phosphorus in sewage, but the adsorption capacity of the adsorption materials is limited and regeneration is difficult, so the cost is high, the operation is troublesome and it is easy to cause secondary pollution

[0008] Chinese Patent Publication No.: CN101602535, introduces "A Phosphorus Recovery Crystallization Reactor and Phosphorus Recovery Method". Low, easy to operate, but the phosphorus recovery efficiency is low (50% ~ 60%), and the turbidity of the effluent is high

Images