Activated Carbon Oxidation Train for Low-COD Wastewater
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Solution Overview
Problem
Existing wastewater treatment systems require excessive activated carbon consumption to achieve low chemical oxygen demand (COD) levels, leading to high costs and resource inefficiencies due to the need for multiple carbon stages and regeneration processes.
Innovation Solution
Incorporating an oxidation stage between two activated carbon stages using ozone, hydrogen peroxide, or ultraviolet light to oxidize treated wastewater, followed by recycling activated carbon through wet air oxidation (WAO) to regenerate and reuse it, thereby reducing total carbon consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If two activated carbon stages are used to reduce COD levels below maximum allowable limits, then COD removal efficiency is improved, but total carbon consumption increases significantly
Solution Approach 1:
The patent implements a carbon recovery system where spent activated carbon from both stages is collected and regenerated through wet air oxidation. The regenerated carbon is then recycled back into the treatment system, replacing the need for continuous fresh carbon addition. This resolves the contradiction by maintaining high COD removal efficiency while significantly reducing total carbon consumption through recovery and reuse of the carbon material.
Solution Approach 2:
The patent applies wet air oxidation to change the chemical state of spent carbon, transforming it from a depleted state to a regenerated state capable of再次 adsorbing organics. By changing the chemical parameters of the carbon through oxidation treatment, the system maintains effective carbon performance across multiple cycles, reducing the quantity of fresh carbon needed while preserving removal efficiency.
2Ease of repair
If spent activated carbon is regenerated by wet air oxidation at elevated temperature and pressure, then carbon reuse is improved, but system complexity and cost increase
Solution Approach 1:
The patent combines the carbon regeneration function with the existing wastewater treatment infrastructure by integrating wet air oxidation into the overall system. Rather than adding completely separate regeneration equipment, the system merges the oxidation process with the treatment train, using the same energy and control systems where possible. This reduces the incremental complexity while enabling carbon reuse.
Solution Approach 2:
The wet air oxidation unit serves multiple functions: it regenerates activated carbon, treats spent carbon for disposal, and can potentially treat other organic wastes. This multi-functionality justifies the added system complexity by providing several benefits from a single added component, improving ease of repair and maintenance through consolidated equipment.
3Productivity
If a second WAO unit is added to handle total carbon consumption, then carbon regeneration capacity is improved, but capital costs and transportation requirements increase
Solution Approach 1:
The patent establishes a continuous carbon regeneration cycle where spent carbon from both stages is continuously fed to the WAO unit for regeneration, and regenerated carbon is continuously returned to the treatment stages. This continuous operation maximizes the utility of the WAO unit, ensuring it operates at high capacity utilization and justifies the capital investment through sustained productivity gains in carbon regeneration.
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 oxidation stage increases the biodegradable fraction of COD, allowing for reduced carbon usage in subsequent stages and overall system efficiency, achieving COD concentrations below 50 mg/L with minimized carbon consumption.
Implementation Method 1
wastewater streams may be contacted with activated carbon for a time effective to remove an amount of chemical oxygen demand (COD) therefrom
Implementation Method 2
activated carbon is further combined with biological material, the latter of which is suitable for the removal of readily biodegradable organics from the wastewater stream
Implementation Method 3
spent activated carbon from the stages may be regenerated by wet air oxidation (WAO) at an elevated temperature, elevated pressure, and in the presence of an oxygen-containing gas
Implementation Method 4
the systems and processes described herein include an oxidation stage (e.g., one that utilizes ozone, hydrogen peroxide, ultraviolet, or any other suitable oxidant/oxidizing agent or a combination thereof for oxidation) between a first activated carbon stage and a second activated carbon stage
Implementation Method 5
an oxidation stage (e.g., one that utilizes ozone, hydrogen peroxide, ultraviolet, or any other suitable oxidant/oxidizing agent or a combination thereof for oxidation)
Implementation Method 6
an oxidation stage (e.g., one that utilizes ozone, hydrogen peroxide, ultraviolet, or any other suitable oxidant/oxidizing agent or a combination thereof for oxidation)
Data Source
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AI summary
The present inventors have developed systems and processes for reducing the overall carbon consumption needed for the generation of low COD treated water. In certain aspects, the systems and processes described herein include an oxidation stage (e.g., one that utilizes ozone, hydrogen peroxide, ultraviolet, or a combination thereof for oxidation) between a first activated carbon stage and a second activated carbon stage to reduce a total carbon consumption within the associated system or process.