Induced Crystallization and Tubular Membrane Filter for Fluorine Removal
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Solution Overview
Problem
High-concentration alkaline fluorine-containing wastewater from industries such as mining and ore processing poses environmental and health risks due to adverse effects on humans, animals, and plants, and existing treatment methods are inadequate in efficiently removing fluorine ions and reducing sludge moisture content.
Innovation Solution
A method combining induced crystallization with a tubular membrane filter (TMF) using specific chemicals like calcium chloride, poly aluminum chloride, tremolite, and polyacrylamide, along with shearing and stirring processes, to treat alkaline fluorine-containing wastewater, enhancing fluorine ion removal efficiency and reducing sludge moisture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional treatment methods are used for high-concentration fluorine-containing wastewater, then the treatment process is simple, but the fluorine ion removal efficiency is insufficient
Solution Approach 1:
The treatment process is divided into multiple stages: first-stage chemical sedimentation, first-stage coagulation sedimentation, second-stage chemical sedimentation, second-stage coagulation sedimentation, and final membrane filtration. Each stage targets specific aspects of fluorine removal and sludge treatment, allowing the system to achieve high removal efficiency through cumulative effect while managing complexity through modular design
Solution Approach 2:
The patent combines multiple treatment mechanisms (chemical sedimentation, coagulation, membrane filtration) and uses composite approaches including chemical reagents (calcium chloride, poly aluminum chloride) combined with physical processes (shearing, membrane separation) to achieve superior fluorine ion removal efficiency that cannot be attained by single methods
2Quantity of substance
If conventional sedimentation methods are used, then the process is simple, but the sludge moisture content remains high
Solution Approach 1:
Before final sedimentation, the patent performs preliminary actions including chemical addition (calcium chloride, poly aluminum chloride), shearing treatment at controlled speeds, and multiple coagulation stages. These preliminary treatments prepare the sludge structure for more effective moisture separation, reducing final sludge moisture content while managing process complexity through staged intervention
Solution Approach 2:
The patent controls and changes multiple parameters including shearing speed (500-1000 rpm), chemical dosages (calcium chloride at specific molar ratios), and sedimentation conditions to optimize sludge dewatering. By precisely controlling these parameters across multiple stages, the system achieves reduced sludge moisture content while the systematic approach manages overall process complexity
3Manufacturing precision
If high dosages of chemical reagents are used to improve fluorine removal, then the removal efficiency increases, but the treatment cost and sludge volume increase
Solution Approach 1:
The patent applies partial action by using moderate dosages of chemical reagents distributed across multiple treatment stages rather than one large dose. The multi-stage approach with controlled chemical addition (calcium chloride, poly aluminum chloride at optimized ratios) achieves cumulative fluorine removal efficiency while reducing total chemical consumption and associated costs
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
Achieves a fluorine ion removal rate of 99% or above, significantly reducing sludge moisture and facilitating secondary wastewater utilization by using tremolite as a seed crystal with calcium fluoride, improving crystallization and treatment efficiency.
Implementation Method 1
performing a treatment on the second-stage effluent by using the TMF to obtain treated second-stage effluent... uses the amphibole var. tremolite with a specific particle size combined with the calcium fluoride as a seed crystal... achieving the induced crystallization
Implementation Method 2
performing a treatment on the second-stage effluent by using the TMF to obtain treated second-stage effluent... discharging the treated second-stage effluent
Implementation Method 3
adding calcium chloride, poly aluminum chloride, calcium fluoride, and tremolite... to obtain first-stage fluorine-containing wastewater
Data Source
AI summary
A method for treating alkaline fluorine-containing wastewater by combining an induced crystallization method with a tubular membrane filter (TMF) includes: introducing fluorine-containing wastewater into a regulating pond to regulate to 8.0-8.5; introducing alkaline fluorine-containing wastewater into a first-stage chemical sedimentation tank, and adding calcium chloride, poly aluminum chloride, calcium fluoride, and tremolite; performing shearing treatment, then introducing into a first-stage coagulation sedimentation tank and a first-stage inclined-tube sedimentation tank in sequence to discharge a first-stage effluent; introducing the first-stage effluent into a second-stage chemical sedimentation tank, adding calcium chloride and poly aluminum chloride, stirring to react, then introducing into a second-stage coagulation sedimentation tank, adding polyacrylamide, and then flowing into a second-stage inclined-tube sedimentation tank, and discharging a second-stage effluent; and performing a treatment by using the TMF, and then discharging a treated second-stage effluent.