Urine Treatment via Acidification and Fermentation for Stable Fertilizer
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Solution Overview
Problem
Urine is not stable for industrial use due to rapid loss of NPK content through hydrolysis of urea into ammonia, posing challenges for its use as a fertilizing material and requiring stabilization and decontamination to meet safety and regulatory standards.
Innovation Solution
A biological method involving acidification of urine to a pH of less than 6, followed by filtration and fermentation, which stabilizes and decontaminates the urine, enriching it with microorganisms, and includes optional steps for precipitating minerals and adding bacteria inoculums for effective fertilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If urine is collected and stored, then it can be used as a fertilizing material, but it quickly loses its NPK content through hydrolysis of urea into ammonia
Solution Approach 1:
The patent applies parameter changes by acidifying the urine to a pH of 4-5, which fundamentally alters the chemical environment. This acidic condition inhibits the hydrolysis of urea into ammonia, thereby preserving the NPK content and stabilizing the urine composition for industrial use as a fertilizing material.
2Reliability
If urine is treated to stabilize and decontaminate it, then it meets safety criteria, but the treatment process becomes complex
Solution Approach 1:
The patent merges multiple treatment functions into a single integrated biological process. By introducing a specific bacterial inoculum that performs both stabilization (preventing urea hydrolysis) and decontamination (reducing pathogenic organisms and micropollutants) simultaneously, the process achieves safety criteria compliance without requiring multiple separate complex treatment stages.
3Reliability
If urine is acidified to stabilize it, then bacteria can survive, but the natural pH of urine (8-9) prevents bacterial growth
Solution Approach 1:
The patent applies preliminary action by pre-acidifying the urine to pH 4-5 before introducing the bacterial inoculum. This preliminary pH adjustment creates a favorable environment for bacterial survival and growth, overcoming the natural alkaline pH (8-9) of urine that would otherwise be hostile to bacteria. The acidification step prepares the medium in advance to support subsequent bacterial colonization.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces a stable, decontaminated urine with a pH of less than 6 and a bacteria concentration of at least 10^6 CFU·mL−1, suitable for use as a fertilizing material, enhancing plant growth and compliance with safety regulations.
Implementation Method 1
a step for acidifying the urine so that the urine will have a pH of less than 6
Implementation Method 2
a step for transforming the urine by fermentation
Implementation Method 3
an optional step before the acidification step, which consists in collecting at least one mineral from the urine in the form of a precipitate
Data Source
AI summary
The subject matter of the invention is a method for treating human or animal urine comprising the implementation of the following steps: —a step for acidifying the urine so that the urine has a pH of less than 6, —a urine filtration step, —a step for transforming the urine by fermentation. The invention also relates to the urine obtained and the co-products of this method, as well as the uses thereof, particularly as a fertilizing material.