Wastewater Nitrogen Removal via Segmented Subsystems
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Solution Overview
Problem
Current wastewater treatment methods are inadequate for efficiently and effectively reducing high nitrogen concentrations, particularly in storm water runoff, as they often result in uncontrolled overflows and fail to meet regulatory standards for discharge.
Innovation Solution
A system comprising a precipitation and conditioning subsystem, an ammonia stripper and neutralization subsystem, and a denitrification subsystem, which includes aeration, caustic addition, ammonia stripping, and biological denitrification to convert nitrogen compounds into nitrogen gas, thereby reducing nitrogen levels below regulatory limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional treatment processes (reverse osmosis, ion exchange, biological treatments) are used to treat high nitrogen-content waste water, then nitrogen removal capability is improved, but device complexity and operational limitations increase
Solution Approach 1:
The treatment system is divided into three distinct subsystems arranged in series: (1) precipitation and conditioning subsystem that adjusts pH and removes suspended solids, (2) ammonia stripper subsystem that removes ammonia through air stripping and chemical neutralization, and (3) denitrification subsystem that converts nitrate to nitrogen gas. This segmentation allows each subsystem to target specific nitrogen forms with optimized processes, achieving reliable high-level nitrogen removal while maintaining manageable complexity through functional specialization.
Solution Approach 2:
The precipitation and conditioning subsystem dynamically adjusts pH parameters to optimize precipitation of metal contaminants and conversion of ammonia to ammonium. The ammonia stripper subsystem controls temperature and air flow parameters to maximize ammonia removal efficiency. The denitrification subsystem maintains specific redox conditions to facilitate nitrate reduction. These parameter changes enable the system to adapt to varying waste water compositions while maintaining effective nitrogen removal.
2Adaptability or versatility
If treatment systems are designed to handle variable volumes of waste water (e.g., during rainfall events), then adaptability is improved, but system overload and uncontrolled overflows increase
Solution Approach 1:
The treatment system incorporates dynamic flow distribution mechanisms that automatically adjust the allocation of waste water among parallel treatment trains based on instantaneous flow rates and nitrogen loads. During high-flow events such as rainfall, the system activates additional treatment capacity and adjusts operational parameters in real-time, preventing overload and uncontrolled overflows while maintaining treatment effectiveness across variable volumes.
Solution Approach 2:
The system employs sensors and control mechanisms that continuously monitor waste water flow rate, nitrogen concentration, and treatment subsystem performance. This feedback information is used to dynamically adjust operational parameters such as air stripping rate, chemical dosing rates, and flow distribution to match actual load conditions, ensuring the system adapts to variable volumes without compromising overflow control or treatment reliability.
3Productivity
If rapid nitrogen removal is achieved through intensive treatment processes, then productivity is improved, but energy consumption and operational costs increase
Solution Approach 1:
The ammonia removal process replaces energy-intensive mechanical aeration with natural air stripping in the ammonia stripper subsystem, where waste water is contacted with air in a controlled environment to volatilize ammonia. The denitrification subsystem uses biological processes driven by organic carbon sources rather than intensive mechanical mixing or chemical addition. These substitutions maintain high nitrogen removal productivity while significantly reducing energy consumption compared to conventional intensive mechanical treatment methods.
Solution Approach 2:
The denitrification subsystem utilizes organic carbon present in the waste water itself as the electron donor for nitrate reduction, eliminating the need for external carbon source addition and associated operational costs. The precipitation subsystem uses pH adjustment to trigger spontaneous precipitation of metal contaminants without requiring complex chemical dosing systems. These self-service mechanisms achieve rapid nitrogen removal while minimizing external energy and material inputs.
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 system efficiently reduces nitrogen levels in wastewater to below 10 ppm, ensuring compliance with environmental discharge regulations and handling sudden rainfall events without system overload, while minimizing complexity and operational costs.
Implementation Method 1
The precipitation and conditioning unit includes an optional water aeration apparatus
Implementation Method 2
a precipitation and conditioning subsystem
Implementation Method 3
an ammonia stripper and neutralization subsystem
Implementation Method 4
The absorber assemblies convert the absorbed ammonia gas to an ammonium salts by reaction with a mineral acid
Implementation Method 5
a denitrification subsystem, where the absorbent is circulated in a bacteria supporting medium. The absorbent is adapted to absorb all or substantially all nitrogen-containing compounds remaining in the water from the ammonia stripper and neutralization unit, while the bacteria convert the absorbed nitrogen-containing compounds into nitrogen gas
Data Source
AI summary
A system of treating high nitrogen content waste water is disclosed, where the system includes a precipitation and conditioning subsystem, an ammonia stripper subsystem, and a denitrification subsystem. The system is adapted to reduce nitrogen contamination to level below about 10 ppm and in certain embodiments below 3 ppm.