Method for recovering nitrogen, phosphorus and potassium from urine sewage

Abstract

The invention provides a method for recovering nitrogen, phosphorus and potassium from urine sewage. The method includes the steps of adding a corresponding agent to adjust the pH for precipitation reaction, recovering nitrogen and phosphorus by generating magnesium ammonium phosphate precipitates, adding a corresponding agent to adjust the pH for precipitation reaction, and recovering phosphorusand potassium by generating potassium phosphate calcium precipitates. Through a practice test, the obtained slow-release type nitrogen and phosphorus compound fertilizer has the nitrogen fertilizer content of 10-20 wt% (according to urea) and the phosphorus fertilizer content of 30-50 wt% (according to phosphorus pentoxide); the obtained slow-release type phosphorus and potassium compound fertilizer has the potassium fertilizer content of 10-12 wt% (according to potassium oxide) and the phosphorus fertilizer content of 30-50 wt% (according to phosphorus pentoxide); the nitrogen recovery rate can reach 80% or above, the phosphorus recovery rate can reach 90% or above, and the potassium recovery rate can reach 70% or above.

Description

technical field [0001] The invention relates to the technical field of urine sewage treatment, in particular to a method for recovering nitrogen, phosphorus and potassium elements from urine sewage. Background technique [0002] Nitrogen, phosphorus and potassium are the three most important nutrient elements in the growth process of crops. However, phosphorus and potassium resources are currently in short supply in countries all over the world, especially in my country. The world's proven reserves of phosphate rock can only last for 80 to 100 years; potash ore is mainly concentrated in a few countries. my country's potassium resources are heavily dependent on imports, and imports of potassium have long been over 70%. Phosphorus and potassium are listed as 2010 by the Ministry of Land and Resources. Important minerals that cannot meet the needs of national economic development. At the same time, water eutrophication is also a thorny issue in water pollution. Uncontrolled se...

AI Technical Summary

Problems solved by technology

However, urine has great limitations as an agricultural liquid fertilizer. Urine requires a huge storage space for 180 days of decomposing, which requires high land occupation and infrastructure costs, and there are problems of nitrogen and phosphorus loss and odor affecting the surrounding environment during decomposing. These limitations Sex limits large-scale application of urine decomposition in urban areas

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