Modular Wastewater Nutrient Removal System
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Solution Overview
Problem
Existing on-site septic systems are inefficient in removing total nitrogen from wastewater, leading to elevated nitrate levels in groundwater and surface water, and are complex to administer and maintain.
Innovation Solution
A modular wastewater treatment system incorporating a nitrification bioreactor, de-nitrification bioreactor, and settling tanks with a flow equalization module and biomass/solids return system, using a compressor/air pump for consistent airflow and carbon-based biofilm carriers to enhance nitrogen removal, addressing the limitations of current systems by achieving over 90% nitrogen removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional septic systems are used, then the system is simple in design, but nitrogen removal efficiency is low (only 70-80% nitrification)
Solution Approach 1:
The system divides the nitrogen removal process into separate functional modules: a nitrification bioreactor for converting ammonia to nitrate, and a de-nitrification bioreactor for converting nitrate to nitrogen gas. This segmentation allows each module to be optimized for its specific function, achieving over 90% nitrogen removal while maintaining manageable system complexity through modular design.
Solution Approach 2:
The patent introduces an intermediary carbon source (such as methanol or acetate) to facilitate the de-nitrification process. This carbon source acts as a mediator that provides the energy needed for de-nitrifying bacteria to convert nitrate to nitrogen gas, enabling complete nitrogen removal while keeping the system design relatively simple.
2Productivity
If de-nitrification is implemented to remove nitrate, then nitrogen removal efficiency improves, but the system requires additional carbon food source and operational complexity
Solution Approach 1:
The patent introduces an intermediary carbon source (such as methanol or acetate) to facilitate the de-nitrification process. This carbon source acts as a mediator that provides the energy needed for de-nitrifying bacteria to convert nitrate to nitrogen gas, enabling complete nitrogen removal while keeping the system design relatively simple.
Solution Approach 2:
The system uses a flow equalization tank that automatically regulates flow to the de-nitrification bioreactor based on the presence of carbon source. This self-regulating mechanism reduces operational complexity by automatically ensuring the carbon source is available when needed for de-nitrification, without requiring manual intervention.
3Productivity
If nitrification is performed in conventional systems, then ammonia conversion occurs, but nitrate accumulates in the drainfield without further treatment
Solution Approach 1:
The patent extracts the de-nitrification function from the conventional septic system by adding a separate de-nitrification bioreactor. This extracted function takes the nitrate produced during nitrification and converts it to nitrogen gas, removing the harmful nitrate contamination that would otherwise accumulate in the drainfield and contaminate groundwater.
Solution Approach 2:
The patent introduces an intermediary carbon source (such as methanol or acetate) to facilitate the de-nitrification process. This carbon source acts as a mediator that provides the energy needed for de-nitrifying bacteria to convert nitrate to nitrogen gas, enabling complete nitrogen removal while keeping the system design relatively simple.
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 effectively removes over 90% of total nitrogen, phosphorus, and biological oxygen demand, reducing maintenance and operational complexity while allowing for easy modification to address additional contaminants, with a simple and efficient design that surpasses the 70% nitrification efficiency of existing systems.
Implementation Method 1
Conversion of ammonia to nitrite and then to nitrate, is called nitrification. It is important to note that nitrification requires and consumes oxygen. The process is mediated by the bacteria Nitrosomonas and Nitrobacter, which require an aerobic environment for growth and metabolism of nitrogen.
Implementation Method 2
The second step of the process, the conversion of nitrate to nitrogen gas, is referred to as de-nitrification. This process is also mediated by bacteria. For de-nitrification to occur, the dissolved oxygen level must be at or near zero.
Implementation Method 3
A first settling tank, a de-nitrification bioreactor and a final settling tank are included in the system
Implementation Method 4
using a compressor/air pump for consistent airflow
Data Source
AI summary
A modular, on-site, wastewater treatment system removes total nitrogen, phosphorus, BOD, and TSS. A flow equalization module provides a constant flow rate to the system eliminating the adverse effects from variations in flow rate throughout the day. Treatment modules are similarly sized to provide a compact, modular system. The nitrification module is a fixed-film, flooded packed bioreactor to facilitate bioconversion of ammonia to nitrate. Aeration of the module provides the oxygen needed for the bioconversion as well prevents clogging of the film. Solids from the nitrification process are removed in a first cone-shaped settling tank. De-nitrification where nitrate is converted to nitrogen gas takes place in an anaerobic fixed-film bioreactor. Carbon-based bio-film carriers provide a carbon source for de-nitrification. A final cone-shaped settling tank separates solids from the treated wastewater. Additional modules to address removal of phosphorous or other contaminants can be added to the modular system.