Liquid Manure Nitrification via Calcium Oxide and Oxygen
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Solution Overview
Problem
The disposal of liquid manure from confined animal spaces leads to environmental pollution and health issues due to ammonia emission, and existing solutions either separate urine and feces prematurely or rely on temporary urease blockers, failing to effectively prevent ammonia production and soil acidification.
Innovation Solution
A method involving the use of nitrifying bacteria to convert ammonium in liquid manure to nitrate, combined with calcium oxide or hydroxide to maintain a pH between 6.5 and 7.5, and passing oxygen to suppress denitrification, resulting in a stable calcium nitrate fertilizer that reduces ammonia release and maintains soil pH.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If liquid manure is stored and transported in liquid form, then it is easy to handle and transport, but ammonia emissions occur during storage and transport causing environmental pollution
Solution Approach 1:
The patent applies preliminary action by converting ammonium to nitrate before storage and transport. The nitrification process is initiated in advance, transforming the manure into a stable form that prevents subsequent ammonia emissions during storage and transport operations.
Solution Approach 2:
The patent changes the chemical parameter of the manure by converting ammonium ions (NH4+) to nitrate ions (NO3-) through nitrification. This parameter change fundamentally alters the stability and emission characteristics of the manure, eliminating ammonia volatility while maintaining liquid form for easy handling.
2Object-generated harmful factors
If urine and faeces are separated before decomposition, then ammonia production is avoided, but additional separation equipment and complexity are required
Solution Approach 1:
The patent converts the harmful ammonia-producing process into a beneficial one by introducing nitrifying bacteria. Instead of preventing decomposition, the process harnesses bacterial nitrification to convert ammonium to nitrate, transforming the potential harm of decomposition into a useful fertilizer product.
Solution Approach 2:
The patent employs self-service by using inherently present nitrifying bacteria in the manure to perform the conversion. No external separation equipment is needed; the system uses its own bacterial population to carry out the nitrification process, simplifying the overall system.
3Object-generated harmful factors
If urease blockers are added to prevent ammonia formation, then ammonia emissions are reduced temporarily, but the solution is expensive and only temporary
Solution Approach 1:
The patent applies preliminary action by establishing nitrification before the manure is discharged or stored long-term. The conversion of ammonium to nitrate is performed in advance, creating a permanent solution rather than a temporary blocker that needs continuous application.
Solution Approach 2:
The patent replaces expensive chemical blockers with a biological process using readily available nitrifying bacteria. The bacteria naturally present in the manure system perform the conversion without requiring continuous addition of costly chemical inhibitors.
4Object-affected harmful factors
If intensive air exchange is used to protect animals from ammonia, then animal health is maintained, but energy consumption increases and external ammonia discharge increases
Solution Approach 1:
The patent converts the harmful ammonia that would require energy-intensive ventilation into useful nitrate through nitrification. By transforming the harmful substance, the need for intensive air exchange and associated energy consumption is eliminated.
Solution Approach 2:
The patent changes the chemical parameter of the manure from ammonium to nitrate form, which fundamentally alters the air quality in the stall. This parameter change eliminates the need for intensive ventilation to protect animal health, reducing energy consumption.
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
This method effectively prevents ammonia production, creates a valuable fertilizer that does not acidify the soil, and can replace traditional nitrogen and calcium fertilizers, while being robust enough to handle varying manure types and storage conditions.
Implementation Method 1
subjecting the liquid manure to nitrifying bacteria (which may be a mixture of different bacteria) to convert ammonium (inherently present in the liquid manure) into nitrate
Implementation Method 2
passing oxygen containing gas through the liquid manure to maintain the oxygen concentration in the liquid manure above 1 mg/l
Data Source
Figure 1
AI summary
The invention pertains to a method to treat liquid manure in order to convert it into a fertiliser composition, the method comprising subjecting the liquid manure to nitrifying bacteria to convert ammonium into nitrate in the presence of denitrifying bacteria, while at the same time suppressing denitrification by adding calcium oxide or calcium hydroxide to the liquid manure to maintain the pH between 6.5 and 7.5, and by passing oxygen containing gas through the liquid manure to maintain the oxygen concentration in the liquid manure above 1 mg/l.