Method for recovering phosphorus by hydrothermally carbonizing livestock manure

Abstract

The invention discloses a method for recovering phosphorus by hydrothermally carbonizing livestock manure. The method comprises the following steps: (1) taking and hydrothermally carbonizing livestockmanure to obtain carbonized product; (2) performing solid-liquid separation on the carbonized product to respectively obtain biochar and a liquid phase product; (3) extracting phosphorus from biocharby an acid leaching process, and performing filtration to obtain a filtrate; and (4) adding a magnesium salt and an ammonium salt to the filtrate, adjusting the pH value to form struvite crystals, and recovering the crystals. The livestock manure is hydrothermally carbonized to degrade pathogens and organic pollutants, and a large amount of phosphorus is recovered from the biochar product as a raw material of a phosphate fertilizer, so the method meets the requirements of reduction, harmlessness and recycling, and has great practical values and economic benefits.

Description

technical field

[0001] The invention belongs to the technical field of environmental engineering, and in particular relates to a method for recovering phosphorus by hydrothermal carbonization of livestock and poultry manure. Background technique

[0002] With the development of my country's livestock and poultry breeding industry, the annual production of livestock and poultry manure in my country is about 3.8 billion tons, but only half of the livestock and poultry manure is comprehensively utilized. Livestock manure has seriously polluted the soil, air and water environment. Livestock manure contains large amounts of phosphorus, which is essential for crop growth. The phosphorus contained in livestock and poultry manure reaches 7 million tons every year, which is equivalent to about 40% of the total amount exploited by human beings. Land application of manure is a traditional method of fertilization, both as a waste disposal option and as a means of recycling nutrients. ...