Method for immobilizing nutrients in pig breeding liquid dung

Abstract

The invention provides a method for immobilizing nutrients in pig breeding liquid dung. The method comprises the following steps: slowly adding calcium superphosphate into livestock liquid dung in anadjusting tank, continuously stirring the mixture, and adjusting the pH value of the livestock liquid dung to 6.0-6.5; wherein the mass of the added calcium superphosphate is 2-5.5% of the mass of thelivestock liquid dung. According to the method, the ammonia gas emission flux can be reduced by 43%-99% in the liquid dung storage process; the fertility of the liquid dung is improved, the number offecal coliform groups in the liquid dung meets the national standard requirement, after the calcium superphosphate is added into the liquid dung, the mixture is stored, and the pig breeding liquid dung is returned to the field for application, the crop yield can be increased, ammonia emission and nitrogen leaching loss in the farmland are reduced, and good ecological and environmental benefits are achieved.

Description

Technical field [0001] The invention relates to the technical field of resource utilization of agricultural wastes, in particular to a method for fixing nutrients in pig farming manure. Background technique [0002] my country’s meat production and consumption is dominated by pork, which accounts for about 56.6% of the total output value of domestic livestock and poultry (pigs, cattle, sheep and poultry). With the rapid development of large-scale breeding in my country, the discharge of pig farming manure has increased sharply. One of the important emission sources of agricultural non-point source pollution, greenhouse gas and ammonia emissions. [0003] At present, the treatment of pig manure water mainly includes two methods: returning to the field after anaerobic fermentation storage and direct storage of manure water back to the field. Among them, anaerobic fermentation has become a vigorously promoted use of manure water with the advantage of its biogas as a clean energy source...

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Problems solved by technology

[0003] At present, the treatment of pig manure water mainly includes anaerobic fermentation storage and returning to the field and direct storage and returning of manure water to the field. Among them, anaerobic fermentation takes the advantage of the biogas produced by it as a clean energy source and has become the most vigorously promoted use of manure water in my country. However, in the production of anaerobic fermentation of manure, the maintenance cost of equipment is relatively high, and the biogas produced by small-scale farms does not have the economic value of utilization, resulting in a lot of biogas being directly discharged into the atmosphere, causing environmental pollution; In terms of direct storage and returning of manure to the field, because manure contains a large amount of urea, the urea decomposes to produce a large amount of ammonium ions. Excessive accumulation of ammonium ions in manure will cause the manure to release a large amount of ammonia gas and pollute the environment.

The dung water is alkaline in the presence of a large amount of ammonium ions. Adding acid to the dung water can store the ammonium ions in the dung water for a long time, improve the fertilizer efficiency of the dung water, and reduce the volatilization of ammonia gas. A method for acidifying and storing breeding manure (CN109516839A), but after common acids are added to the manure, the pH of the manure will rise rapidly in a short period of time after dropping to the target pH, and it is necessary to add acid several times to stabilize the pH of the manure , can not stably reduce the release of ammonia gas in the storage of pig manure, and is not suitable for the management of manure acidification in farms

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