Ballasted Flocculation Adsorbent Recycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing water treatment techniques, particularly those involving adsorption, face challenges due to poor control of adsorbent reagent consumption, leading to either insufficient or excessive reagent use, resulting in subpar water quality and increased costs.
Innovation Solution
A process that includes a pre-contact zone with powdered adsorbent, followed by ballasted flocculation and settling, with continuous measurement and controlled injection of new adsorbent reagent to maintain optimal concentration, and acidification to enhance adsorption capacity, recycling sludge and adsorbent to reduce waste and consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If adsorbent reagent is injected into water treatment zones, then the content of dissolved and suspended impurities is reduced, but the consumption of adsorbent reagent becomes uncontrolled leading to either insufficient treatment or excessive reagent presence in treated water
Solution Approach 1:
The adsorbent reagent is pre-mixed with sludge from the settling zone to form a pre-treated adsorbent mixture before being reintroduced to the coagulation-flocculation process. This preliminary preparation optimizes the adsorbent's effectiveness and controls its consumption by ensuring it is properly conditioned before contact with raw water.
Solution Approach 2:
Instead of discarding the sludge from the settling zone, it is recovered and reused as a carrier for the adsorbent reagent. This recycling approach controls reagent consumption by concentrating the adsorbent on the sludge particles, which are then removed with the flocs, preventing excessive adsorbent presence in the treated water.
2Manufacturing precision
If excessive adsorbent reagent is supplied to reduce impurities, then the reduction of colloidal impurities is significant, but the treated water quality deteriorates due to high presence of particles in the water
Solution Approach 1:
The sludge containing the adsorbent reagent and adsorbed impurities is recovered from the settling zone and reused in the coagulation-flocculation process. This ensures that the adsorbent, along with the captured impurities, is removed with the flocs, preventing particle overload in the treated water while maintaining effective impurity reduction.
Solution Approach 2:
The system creates a feedback loop where the sludge from the settling zone is returned to the coagulation-flocculation zone, allowing the adsorbent to work in a controlled cycle. This feedback mechanism ensures optimal adsorbent utilization and prevents excessive reagent accumulation in the treated water.
3Quantity of substance
If insufficient adsorbent reagent is supplied, then the treatment cost is reduced, but the reduction by adsorption of impurities is limited and treated water does not meet drinkability criteria
Solution Approach 1:
The sludge is recovered and reused as a carrier for the adsorbent reagent, which concentrates the adsorbent on solid particles. This increases the effective adsorption capacity per unit of adsorbent reagent, allowing for reduced overall consumption while maintaining or improving treatment effectiveness.
Solution Approach 2:
The system creates a composite material by combining sludge and adsorbent reagent together. This composite structure enhances the adsorption efficiency, allowing the adsorbent to work more effectively on the sludge particles, thereby improving impurity removal while controlling reagent consumption.
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 ensures the production of high-quality water while minimizing adsorbent consumption and treatment costs, maintaining effective adsorption capacity and reducing residual adsorbent in treated water.
Implementation Method 1
The treatment of water by adsorption is most often obtained by injecting into the water at least one reagent having adsorbent properties such as activated carbon
Implementation Method 2
The injection of ballast leads to the relatively rapid formation of ballasted floc whose settling speed is increased compared to that of a conventional floc
Implementation Method 3
Coagulation generates an agglomeration of colloidal particles suspended in water
Implementation Method 4
Flocculation causes the formation of flocs by agglomeration of previously coagulated colloidal particles
Data Source
Figure 1
AI summary
The invention relates to a method for treating raw water laden with impurities in a treatment facility including at least one step of placing water in contact with a powdered adsorbent agent in an agitated pre-contact area (2), a step of ballasted flocculation, a step of settling, extracting a mixture of sludge, ballast and the powdered adsorbent agent from the bottom of the settlement area (5), and inserting the mixture in a hydrocyclone (11), transporting the overflow consisting of a mixture of sludge and powdered adsorbent reagent from said hydrocyclone (11) to a transition area (14). The method also includes a step of recycling the mixture of sludge and powdered adsorbent agent from the transition area (14) in the pre-contact area (2), continuously measuring at least one datum showing the concentration of powdered adsorbent agent in the pre-contact area (2), and a step of injecting a suspension of new powdered adsorbent agent in an aqueous medium upstream when the concentration of powdered adsorbent agent in the pre-contact area (2) is below a predetermined threshold value, as well as a step of acidifying said suspension of adsorbent agent.