Device and method for recycling phosphorus by virtue of induced crystallization

Abstract

The invention relates to environmental protection and resource recycling techniques and devices and particularly relates to an induced crystallization reactor, a solid-liquid separation device and a method for efficiently recycling phosphorus from sewage. The induced crystallization reactor and the solid-liquid separation device comprise an water inlet part, a medicating part, an acidity regulating part, an aeration stirring part, an induced crystallization reaction part, a solid-liquid separation part and a crystal recycling part, wherein the induced crystallization reactor is communicated with the solid-liquid separation device to adequately play seed crystal induction function. According to the device and the method, calcite is utilized as a seed crystal for inducing phosphorus in sewage so as to recycle phosphorus in a form of hydroxyl calcium phosphate crystals, and the recycled product can be directly applied to industrial and agricultural production, so that the sewage treatment, the environmental protection and the resource reutilization are organically combined. Besides, the method has the characteristics of small occupied area, high recycling efficiency, good quality of the recycled product, little equipment investment and convenient 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 leading to eutrophication of water bodies. According to Liebig's law of minimum factors, phosphorus is the key factor leading to eutrophication of water bodies (C 106 h 263 o 110 N 16 P) is a limiting factor for growth, and many countries have strict restrictions on its emission concentration. 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 w...

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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 an adsorption material containing phosphorus compounds such as amino to adsorb phosphorus in sewage, but the adsorption capacity of the adsorption material 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

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