Membrane Filtrate Phosphonate Removal via Sludge Adsorption
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Solution Overview
Problem
Membrane filtration techniques in water treatment produce significant discharges loaded with phosphonates, which are environmentally harmful and costly to manage, particularly in drinking water production units.
Innovation Solution
A method that includes a pretreatment step with coagulation-flocculation, followed by membrane filtration and an additional coagulation-flocculation step with an adsorption phase using sludge to reduce phosphonates in the rejects, allowing for phosphonate removal and reducing coagulant dosage, thereby minimizing environmental impact and operational costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If membrane filtration is used to remove pollutants, then water purification is improved, but phosphonate concentration in discharges increases
Solution Approach 1:
The patent introduces sludge as an intermediary substance to adsorb phosphonates from the concentrate stream. The sludge acts as a mediator between the phosphonate-containing water and the final discharge, capturing the harmful substances through adsorption onto solid particles, thereby reducing phosphonate concentration in the treated effluent
Solution Approach 2:
The patent changes the physical-chemical parameters of the concentrate by adjusting pH and adding coagulants to optimize phosphonate adsorption onto sludge. By modifying parameters such as pH level and ionic composition, the process enhances the adsorption capacity of sludge for phosphonates, enabling effective removal before discharge
2Quantity of substance
If conventional coagulation-flocculation is applied to treat concentrates, then phosphonate removal is improved, but coagulant consumption increases
Solution Approach 1:
The patent employs sludge generated within the same treatment process to treat the concentrate stream, creating a self-service system. The sludge produced during pretreatment is reused to adsorb phosphonates from the concentrate, eliminating the need for additional coagulant chemicals and reducing chemical consumption while maintaining effective phosphonate removal
Solution Approach 2:
Instead of discarding the sludge from pretreatment as waste, the patent recovers its adsorption capacity by using it to treat the concentrate stream. The sludge is regenerated through the adsorption process and then disposed of or further treated after having removed phosphonates, thereby recovering its utility and avoiding additional chemical purchases
3Object-generated harmful factors
If sludge adsorption is added to the process, then phosphonate elimination is improved, but process complexity increases
Solution Approach 1:
The patent merges the sludge adsorption step with the existing concentrate treatment流程 by integrating it into the coagulation-flocculation sequence. The sludge addition and adsorption process is combined with the existing chemical treatment train, allowing phosphonate removal to be achieved through a unified process rather than separate sequential steps, thereby minimizing additional 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
Effectively reduces phosphonate content in membrane filtration discharges, lowers coagulant consumption, and enables the recovery and reuse of excess sludge for agricultural purposes, enhancing soil fertilization and reducing environmental pollution.
Implementation Method 1
at least one adsorption step on at least a portion of said sludge from the pretreatment and/or on a portion of said sludge from said settling step, said adsorption step aimed at reducing the phosphonates contained in said rejects from said membrane filtration step
Implementation Method 2
said first pretreatment step comprises a first coagulation-flocculation step
Implementation Method 3
said first pretreatment step comprises a first coagulation-flocculation step
Implementation Method 4
followed by a settling step producing sludge
Data Source
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AI summary
The subject of the invention is a water treatment process, comprising a first pretreatment step that produces pretreated water and sludge, said pretreated water then undergoing at least one membrane filtration step that produces waste and a permeate, said permeate being conveyed to a potabilization system characterized in that said first pretreatment step comprises a first coagulation/flocculation step, and in that said waste resulting from said membrane filtration step undergoes a treatment phase that includes at least one second coagulation/flocculation step followed by a settling step that produces sludge, said settling step being preceded by at least one step of adsorption onto at least one portion of said sludge resulting from the pretreatment and/or onto a portion of said sludge originating from said settling step, said adsorption step targeting a reduction of the phosphonates contained in said waste resulting from said membrane filtration step, said process resulting in treated waste and in excess sludge.