EDI Water Treatment Using Iodine Oxidation for Slime Control
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Solution Overview
Problem
Existing water treatment methods using electrodeionization (EDI) devices face issues with slime generation leading to increased differential pressure and decreased water quality due to the use of oxidizing agents, which also deteriorate the ion exchange resin and membranes, necessitating lengthy cleaning processes that disrupt operation.
Innovation Solution
The use of an iodine-containing oxidizing agent as a slime inhibitor in the EDI device, combined with an anion exchanger, allows continuous operation without deteriorating water quality or increasing pressure, by adding the agent to the water before treatment and ensuring at least part of the ion exchanger is an anion exchanger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxidizing agents (hypochlorous acid, hydrogen peroxide, ozone) are added to water to suppress slime, then slime growth is inhibited, but the ion exchange resin and membrane are deteriorated
Solution Approach 1:
The patent changes the chemical parameter by using iodine-containing oxidizing agents instead of conventional oxidizing agents (hypochlorous acid, hydrogen peroxide, ozone). This parameter substitution maintains the oxidizing capability needed for slime suppression while reducing the harmful impact on ion exchange resin and membrane durability.
2Reliability
If conventional oxidizing agents are used for slime removal, then slime is suppressed, but voltage application must be stopped or weakened, preventing deionization treatment
Solution Approach 1:
The patent substitutes conventional oxidizing agents with iodine-containing oxidizing agents, changing the chemical parameter to enable both slime control and continuous deionization treatment without requiring voltage interruption or reduction.
3Object-generated harmful factors
If chemical cleaning is performed to remove slime, then slime is removed from the device, but the cleaning process takes several days and the device cannot be used during cleaning
Solution Approach 1:
The patent implements a self-service approach where iodine-containing oxidizing agents are continuously added to the water supply, enabling the EDI device to suppress and remove slime during normal operation without requiring separate cleaning cycles that would cause device downtime.
4Productivity
If oxidizing agents are used to prevent slime blockage, then water flow is maintained, but the oxidizing agents deteriorate the ion exchange components
Solution Approach 1:
The patent changes the chemical composition parameter by using iodine-containing oxidizing agents instead of conventional oxidizing agents, maintaining the water flow benefits while preserving ion exchange component integrity through reduced chemical deterioration.
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 maintains high water quality and prevents pressure increases in the EDI device, while effectively inhibiting slime growth and preserving the integrity of the ion exchange components.
Implementation Method 1
The slime inhibitor is composed of, for example, hypochlorous acid, hydrogen peroxide, ozone, or the like which have a bactericidal action
Implementation Method 2
at least the deionization chamber is filled with an ion exchanger such as an ion exchange resin, and, by applying a DC voltage between the anode and the cathode while passing the water to be treated through the deionization chamber, treated water from which ion components have been removed flows out
Implementation Method 3
The EDI device is a device in which electrophoresis and electrodialysis are combined
Implementation Method 4
The EDI device is a device in which electrophoresis and electrodialysis are combined
Data Source
AI summary
A water treatment method includes: adding a chemical to water to be treated to obtain water to be treated which contains iodine and is provided with oxidizing power; and supplying the water to be treated that has undergone the chemical addition to an electrodeionization device (EDI device) to treat the water to be treated in the EDI device. At least a part of an ion exchanger filled in a deionization chamber of the EDI device is an anion exchanger.