Immobilization method for nutrients in cow dung water

Abstract

The invention provides an immobilization method for nutrients in cow dung water. The immobilization method comprises the following steps: slowly adding calcium superphosphate into cow dung water in anadjusting tank, continuously performing stirring, and adjusting the pH value of the cow dung water to 6.0-6.5, wherein the addition amount of the calcium superphosphate is 2-15% of the mass fractionof the cow dung water. According to the invention, ammonia gas emission flux in the storage process of the cow dung water can be reduced by 7.6-21.3%, so the fertilizer efficiency of the cow dung water is improved; meanwhile, the number of fecal coliform groups in the cow dung water meets the national standard requirement in China, the cow dung water is added with calcium superphosphate before storage and then returned and applied to fields, so crop yield can be increased; and ammonia emission and nitrogen leaching loss in farmland are reduced, and good ecological and environmental benefits are achieved.

Description

Technical field [0001] The present invention relates to the technical field of resource utilization of agricultural wastes, in particular to a method for fixing the nutrients of cow manure water. Background technique [0002] With the rapid development of large-scale farming in my country, the amount of cow manure water discharge has increased sharply. Pig farms generally clean manure by dry manure removal, and the amount of water generated is relatively small, but cattle farms, especially dairy farms, The amount of manure water is relatively large. Because the manure water produced by cattle farms has a high solid content and is difficult to treat, it has become one of the important emission sources of agricultural non-point source pollution, greenhouse gas and ammonia emissions. [0003] At present, the treatment of manure water mainly includes two methods of returning to the field after anaerobic fermentation storage and direct storage of manure water. Among them, anaerobic ferme...

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Problems solved by technology

[0003] At present, the treatment of 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 main method of manure water utilization vigorously promoted in my country. The main method, but in the anaerobic fermentation of manure, the maintenance cost of equipment is high, and the biogas produced by small-scale farms does not have the economic value of utilization, so a lot of biogas is directly discharged into the atmosphere, causing environmental pollution; In terms of direct storage and returning of manure to the field, since the manure contains a large amount of urea, the urea decomposes to produce a large amount of ammonium ions. Excessive accumulation of ammonium ions in the 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 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 poultry breeding manure (CN109516839A), but after common acids are added to the manure, the pH value 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 manure pH, can not stably reduce the release of ammonia in the storage of cow manure water, it is not suitable for the management of manure acidification in farms

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