Water Treatment Adsorbent Recirculation for Micropollutant Removal
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Solution Overview
Problem
Current water treatment processes using powdered activated carbon are inefficient due to competition between organic matter and micropollutants for adsorption sites, leading to increased treatment costs and suboptimal use of adsorption capacities, as well as the need for additional clarification stages and capital investments.
Innovation Solution
A process that recirculates spent adsorbent into preadsorbed water, optimizing adsorption capacity by maintaining contact between adsorbent and water for extended periods, and incorporating coagulation and flocculation stages to reduce competition and enhance adsorption efficiency, without requiring intermediate clarification structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional water treatment processes use powdered activated carbon for adsorption, then micropollutants and organic matter can be removed from water, but the adsorption performance is strongly reduced due to competition between organic matter and micropollutants for binding sites
Solution Approach 1:
The invention divides the adsorption process into two distinct stages: a first adsorption stage using activated carbon to remove micropollutants, followed by a second adsorption stage using a different adsorbent material to remove organic matter. This segmentation prevents the competition for binding sites that occurs in conventional single-stage processes, thereby maintaining high adsorption performance for micropollutants while reducing the total amount of activated carbon needed.
Solution Approach 2:
The invention applies different adsorbent materials with specific properties tailored to each stage of treatment. The first adsorbent (activated carbon) is optimized for micropollutant removal, while the second adsorbent is selected based on its specific affinity for organic matter. This local optimization of adsorbent properties at different stages eliminates the need to use excessive activated carbon to compete with organic matter for binding sites.
2Reliability
If conventional treatment processes increase the amount of activated carbon to overcome competition from organic matter, then micropollutant removal efficiency improves, but treatment costs increase
Solution Approach 1:
By segmenting the adsorption process into two stages with different adsorbents, the invention eliminates the need to use excessive amounts of activated carbon to overcome competition from organic matter. Each adsorbent is deployed where it is most effective, maintaining high micropollutant removal efficiency while minimizing the quantity of activated carbon required and thus reducing treatment costs.
Solution Approach 2:
The invention changes the parameter of adsorbent type between stages rather than maintaining a single adsorbent throughout. This parameter change allows the first stage to optimize for micropollutant removal with activated carbon, while the second stage uses a different adsorbent optimized for organic matter removal, thereby achieving the same or better removal efficiency at lower cost.
3Reliability
If conventional processes use separate coagulation and adsorption stages, then treatment performance is maintained, but additional clarification structures and capital investment are required
Solution Approach 1:
The invention merges the coagulation and adsorption stages into a single integrated process. The adsorbent materials are introduced in the coagulation stage itself, allowing simultaneous coagulation and adsorption to occur without requiring separate clarification structures. This integration maintains treatment performance while reducing device complexity and capital investment.
Solution Approach 2:
The invention makes the coagulation stage multi-functional by incorporating adsorption capability within it. The adsorbent materials serve dual purposes: they participate in the coagulation process while simultaneously adsorbing micropollutants and organic matter. This multi-functionality eliminates the need for dedicated adsorption clarification structures, reducing overall system complexity.
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 enhances the overall performance of water treatment by maximizing adsorbent capacity utilization, reducing treatment costs, and achieving comparable results to traditional methods without the need for additional clarification stages or excessive capital investment.
Implementation Method 1
The removal of these compounds by adsorption takes effect by virtue of a surface phenomenon by which the molecules become attached to the solid surfaces of the activated carbon via different forces (electric charges, dipole-dipole interaction, Van der Waals forces) or bonds (hydrogen bonds, covalent bonds, and the like)
Implementation Method 2
coagulation and adsorption (on the particulate matter present in the water, on the sludges produced during the treatments or also on a specific absorbent material) appear to be two main treatment routes
Implementation Method 3
incorporating coagulation and flocculation stages to reduce competition and enhance adsorption efficiency
Data Source
AI summary
Disclosed is a method for treating water including: —an adsorption step which involves bringing the water into contact with a new adsorbant, the water being referred to as “pre-adsorbed water” before being brought into contact with the new adsorbant, and being referred to as “adsorbed water” after being brought into contact with the new adsorbant, and—a recirculation step which involves removing at least a portion of the new adsorbant brought into contact with the water during the adsorption step, the removed portion constituting a used adsorbant. During the recirculation step, the used adsorbant is brought into contact with the pre-adsorbed water. Also, the pre-adsorbed water does not undergo a clarification step that involves eliminating from the water at least a portion of the suspended matter that it contains. Also disclosed is a device for implementing such a method.