Denitrification Activity Control via Molybdenum and Nitrogen Loading
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Solution Overview
Problem
Existing denitrification methods face challenges in maintaining high denitrification activity and treatment speed, particularly when using fluid carriers, due to unclear nutrient requirements and excessive nutrient additions leading to increased costs and potential residual metal treatment issues.
Innovation Solution
A water treatment method involving a biological treatment tank with heterotrophic denitrifying bacteria and a hydrogen donor, where 0.01 to 1.0 mgMo/gN of molybdenum is added, and a carrier is used to maintain high denitrification activity and increase treatment speed by optimizing nitrogen loading to at least 1.6 kgN/(m3-carrier·d.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal salts are added to supply nutrients for denitrifying bacteria, then denitrification activity can be maintained, but running costs increase and residual metal treatment may be required
Solution Approach 1:
The invention changes the parameter of nutrient supply from excessive metal salt addition to precise controlled addition based on nitrogen loading. By establishing the relationship between nitrogen loading and optimal molybdenum concentration (0.01 to 1.0 mg Mo/g N), the system maintains high denitrification activity while minimizing metal salt usage and avoiding residual metal treatment issues.
Solution Approach 2:
The invention implements feedback control by monitoring nitrogen loading conditions and adjusting molybdenum concentration accordingly. The system uses nitrogen loading as a feedback parameter to determine the optimal molybdenum concentration range, ensuring that nutrients are supplied at the right amount to maintain denitrification activity without excessive addition.
2Reliability
If large amounts of nutrients are added to maintain denitrification activity, then bacterial activity can be sustained, but treatment costs increase
Solution Approach 1:
The invention optimizes the parameter of nutrient concentration by establishing the specific range of 0.01 to 1.0 mg Mo/g N based on nitrogen loading. This precise parameter control ensures sufficient denitrification activity while minimizing nutrient addition amounts, thereby reducing treatment costs without sacrificing bacterial activity.
Solution Approach 2:
The invention applies partial action by adding only the necessary amount of molybdenum (0.01 to 1.0 mg Mo/g N) required to maintain denitrification activity rather than adding excessive nutrients. This optimized addition amount is sufficient to sustain bacterial activity while avoiding the increased costs associated with over-addition.
3Productivity
If nitrogen loading is increased to improve treatment speed, then reaction tank volume can be reduced, but denitrification activity may decrease without optimal nutrient control
Solution Approach 1:
The invention simultaneously optimizes two parameters: nitrogen loading (increased to improve treatment speed) and molybdenum concentration (optimized to 0.01 to 1.0 mg Mo/g N to maintain activity). By coordinating these parameter changes, the system achieves high treatment speed through increased nitrogen loading while preventing activity decline through optimized nutrient supply.
Solution Approach 2:
The invention uses nitrogen loading as a feedback parameter to determine the appropriate molybdenum concentration. As nitrogen loading increases to improve treatment speed, the system adjusts molybdenum concentration within the 0.01 to 1.0 mg Mo/g N range to maintain denitrification activity, ensuring both productivity and reliability are achieved.
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 effectively maintains high denitrification activity and increases treatment speed by determining the optimal molybdenum concentration based on nitrogen loading, improving treatment performance and reducing reaction tank volume requirements.
Implementation Method 1
By subjecting at least one of nitrate nitrogen and nitrite nitrogen in a water to be treated to a denitrification treatment by denitrifying bacteria in the presence of a hydrogen donor, the at least one of nitrate nitrogen and nitrite nitrogen can be decomposed to obtain nitrogen gas
Implementation Method 2
0.01 to 1.0 mgMo/gN of molybdenum is allowed to be present in the water to be treated, wherein the denitrification activity of the denitrifying bacteria can be maintained at a high level
Implementation Method 3
a carrier is added to the biological treatment tank, with the nitrogen loading relative to the carrier set to equal to or more than 1.6 kgN/(m3-carrier·d)
Data Source
AI summary
Provided are: a water treatment method that includes at least a denitrification step for denitrifying water to be treated with a denitrifying bacterium in the presence of a hydrogen donor, wherein the denitrification activity of the denitrifying bacterium can be maintained at a high level and thus the treatment speed can be increased; and a water treatment apparatus. The water treatment method includes at least a denitrification step for passing water to be treated through a biological treatment tank and denitrifying the same with a heterotrophic denitrifying bacterium in the presence of a hydrogen donor, wherein: molybdenum is added to the water to be treated to give a concentration of 0.01-1.0 mgMo/gN; a carrier is added to the biological treatment tank; and the nitrogen load to the carrier is controlled to 1.6 kgN/(m3-carrier·d) or greater.