Buffer Chamber Electrodialysis for Wastewater Treatment
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Solution Overview
Problem
Traditional electrodialysis systems with bipolar membranes suffer from concentration polarization, leading to increased ion migration resistance and inefficient recovery of acid and basic solutions, as well as inability to separate ions with the same electrical properties, resulting in reduced purity of recovered solutions.
Innovation Solution
Incorporating a buffer chamber between the wastewater chamber and either the acid or basic solution chamber, equipped with ion exchange membranes of the same electrical properties as the respective solution, to maintain optimal ion concentrations and prevent back diffusion, thereby enhancing treatment efficiency and solution recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a traditional electrodialysis device with bipolar membrane is used, then the structure is simple, but concentration polarization occurs leading to increased ion migration resistance and reduced treatment efficiency
Solution Approach 1:
The device is segmented into multiple chambers including buffer chambers inserted between the acid solution chamber/basic solution chamber and the wastewater chamber. This segmentation prevents concentration polarization by creating intermediate zones, thereby maintaining ion migration efficiency while treating wastewater.
Solution Approach 2:
Buffer chambers act as intermediary zones between the acid/basic solution chambers and the wastewater chamber. These intermediary buffer chambers prevent direct concentration polarization by providing a transition zone, thus maintaining efficient ion migration while enabling effective wastewater treatment.
2Device complexity
If a traditional electrodialysis device with bipolar membrane is used, then the device structure is simple, but the recovery efficiency of acid solution and basic solution is low due to back diffusion
Solution Approach 1:
The device is segmented into multiple chambers including buffer chambers inserted between the acid solution chamber/basic solution chamber and the wastewater chamber. This segmentation prevents concentration polarization by creating intermediate zones, thereby maintaining ion migration efficiency while treating wastewater.
Solution Approach 2:
Buffer chambers act as intermediary zones between the acid/basic solution chambers and the wastewater chamber. These intermediary buffer chambers prevent direct concentration polarization by providing a transition zone, thus maintaining efficient ion migration while enabling effective wastewater treatment.
3Device complexity
If only standard anion exchange membrane and standard cation exchange membrane are used, then the device is simple, but ions with the same electrical properties cannot be separated resulting in reduced purity
Solution Approach 1:
Different types of ion exchange membranes (strong acid, strong base, weak acid, weak base) are selectively applied at different locations within the device. This local differentiation enables separation of ions with the same electrical properties while maintaining a manageable device structure.
Solution Approach 2:
The device employs composite membrane structures combining different types of ion exchange membranes (strong acid, strong base, weak acid, weak base) in specific configurations. This composite approach enables selective ion separation while maintaining structural integrity and operational efficiency.
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 buffer chamber system improves wastewater treatment efficiency and solution recovery by maintaining ion concentration gradients, reducing osmotic pressure differences, and enabling effective separation of ions with the same electrical properties, resulting in higher purity and efficiency of acid and basic solution production.
Implementation Method 1
An interface between the wastewater chamber and the first buffer chamber is a first ion exchange membrane. An interface between the first buffer chamber and the one of the acid solution chamber and the basic solution chamber is a second ion exchange membrane.
Implementation Method 2
the electrodialysis (ED) device can convert the salts in the wastewater into acid solution and basic solution
Data Source
AI summary
Provided are a system and a method of treating wastewater. The system includes a wastewater chamber, positive and negative electrode chambers, acid and basic solution chambers and a buffer chamber. The wastewater chamber receives wastewater containing a first ion. The positive and the negative electrode chambers are respectively on opposite sides of the wastewater chamber. The acid chamber is between the wastewater chamber and the positive electrode chamber. The basic chamber is between the wastewater chamber and the negative electrode chamber. The buffer chamber is between one of the acid and the basic chambers and the wastewater chamber, and receives the buffer solution containing the first ion. The interfaces between the wastewater chamber and the buffer chamber and between the one of the acid and the basic chambers and the buffer chamber are ion exchange membranes having the same electrical properties.