Bioaugmentation for Nitrogen Removal in Wastewater Reactors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wastewater treatment plants face challenges in efficiently removing nitrogen from wastewater due to slow aerobic nitrification reactions by autotrophic organisms, limiting the volume requirements for nitrogen removal.
Innovation Solution
The process involves bioaugmentation of seed autotrophic and denitrification organisms to enhance nitrification and denitrification rates within a smaller volume or shorter solids retention time, with separate treatment of high ammonia digester reject water to enrich seed cultures and return treated sludge to the mainstream reactor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional nitrification by slow-growing autotrophic organisms is used, then nitrogen removal is achieved, but the reaction rate is slow and large volume is required
Solution Approach 1:
The patent applies preliminary action by pre-growing and enriching nitrifying bacteria in a separate seed production reactor before introducing them to the mainstream reactor. This pre-preparation of high-concentration nitrifying seed sludge allows the mainstream reactor to achieve rapid nitrogen removal without requiring large volume, as the beneficial microorganisms are introduced in advance in concentrated form
Solution Approach 2:
The patent changes the concentration parameter of nitrifying bacteria by operating the seed production reactor under conditions that enrich autotrophic organisms (controlled DO, ammonia loading). This parameter change from low to high bacterial concentration enables the mainstream reactor to achieve high nitrogen removal rates in smaller volume
2Productivity
If conventional denitrification processes are used, then nitrogen removal is achieved, but large volume and high methanol requirements are needed
Solution Approach 1:
The patent applies preliminary action by pre-growing denitrifying bacteria in the seed production reactor alongside nitrifying bacteria. The seed production reactor is designed to produce mixed culture seed sludge containing both nitrifiers and denitrifiers, which are then introduced to the mainstream reactor to enable rapid denitrification without requiring large dedicated denitrification volume
Solution Approach 2:
The patent merges the production of nitrifying and denitrifying bacteria in a single seed production reactor. This combined approach produces mixed culture seed sludge that contains both functional groups, allowing the mainstream reactor to perform both nitrification and denitrification with reduced volume requirements and lower methanol dosing
3Productivity
If separate treatment of digester reject water is performed, then high ammonia stream is treated efficiently, but additional process steps are required
Solution Approach 1:
The patent merges the treatment of digester reject water with the seed production process. The seed production reactor receives both synthetic wastewater and digester reject water, combining seed production with high-strength ammonia treatment. This integration eliminates the need for separate reject water treatment trains while producing enriched nitrifying seed sludge as a valuable byproduct
Solution Approach 2:
The patent converts the harmful high-ammonia reject water stream into a beneficial resource by using it as substrate in the seed production reactor. The high ammonia concentration that would otherwise require complex treatment is instead used to enrich nitrifying bacteria, transforming a waste stream into a valuable seed culture production medium
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 approach reduces methanol requirements, denitrification and nitrification volumes by 25-50%, and allows for efficient nitrogen removal and treatment of high-strength reject water, while maintaining steady-state seed mass and controlling seed addition in the mainstream process.
Implementation Method 1
nitrifying bacteria convert ammonia to nitrite and subsequently to nitrate
Implementation Method 2
denitrification of nitrite or nitrate to nitrogen gas
Data Source
AI summary
An efficient system and process for removing nitrogen from wastewater while enriching seed sludge in the mainstream treatment process. Bioaugmentation of seed autotrophic organisms facilitate the nitrification reactions by enhancing the rates of reaction advantageously within a smaller volume or within a shorter activated sludge solids retention time. Likewise, bioaugmentation of seed denitrification organisms will also enhance rate of reaction within a smaller volume or shorter activated sludge solids retention time. Separate treatment of high ammonia digester reject water is an efficient method to treat nitrogen in recycle streams as well as to enrich the seed nitrifying and denitrifying cultures.