CNT–MXene Composite Membrane for Precious Metal Recovery in Oily Wastewater
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Solution Overview
Problem
Existing carbon nanotube membranes are inefficient in recovering precious metal ions from complex oily wastewater due to their unsatisfactory performance in such environments.
Innovation Solution
A functional membrane is prepared by functionalizing carbon nanotubes with polyacrylic acid and acyl hydrazine groups, combined with MXene nanosheets, through graft polymerization and vacuum filtration, to enhance recovery efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon nanotube membranes are used for recovering precious metal ions from oily wastewater, then the membrane structure provides good mechanical properties and porous network, but the recovery efficiency is unsatisfactory due to complex pollutant compositions
Solution Approach 1:
The patent creates a composite membrane structure by integrating functionalized carbon nanotubes (with carboxyl and acyl hydrazine groups) into a porous substrate. This composite approach combines the mechanical strength and porous network of carbon nanotubes with the selective recovery capabilities of functional groups, enabling efficient precious metal ion recovery from complex oily wastewater while maintaining structural integrity
Solution Approach 2:
The patent introduces specific functional groups (carboxyl and acyl hydrazine) at localized positions on the carbon nanotube surfaces. These localized functional groups provide specific chemical affinity for precious metal ions, enhancing recovery efficiency without compromising the overall mechanical properties and porous structure of the membrane
2Reliability
If carbon nanotubes are oxidized using strong oxidizing acids to enhance precious metal ion recovery, then the surface functional groups improve recovery capability, but the membrane structure may be damaged
Solution Approach 1:
The patent optimizes the oxidation parameters (oxidizing agent concentration, treatment time, temperature) to achieve the desired level of surface functionalization while minimizing structural damage. By carefully controlling these parameters, the membrane maintains its mechanical strength and porous structure while acquiring sufficient functional groups for effective precious metal ion recovery
3Device complexity
If most separation membranes are designed for single aqueous solution, then the membrane structure is simple, but the performance in complex oily wastewater is unsatisfactory
Solution Approach 1:
The patent designs the membrane with multiple functional groups (carboxyl and acyl hydrazine) that can interact with various types of pollutants in complex oily wastewater. This multi-functional design enables the membrane to perform both oil-water separation and precious metal ion recovery simultaneously, making it adaptable to complex wastewater compositions while maintaining a relatively simple overall structure
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 composite membrane achieves high recovery efficiency of precious metal ions and improved oil-water separation, with synergistic enhancement in both processes.
Implementation Method 1
obtaining carbon nanotubes functionalized by polyacrylic acid (CNTs-PAA) by grafting acrylic acid onto a surface of carbon nanotubes (CNTs) via graft polymerization
Implementation Method 2
obtaining carbon nanotubes modified by acyl hydrazine functional groups (CNTs-PAH) by reacting adipic dihydrazide with carboxyl functional groups of the CNTs-PAA
Implementation Method 3
preparing single-layer MXene nanosheets using Ti3AlC2 powder
Implementation Method 4
preparing a CNTs-PAH/MXene composite membrane by vacuum filtration based on the CNTs-PAH and the MXene nanosheets
Implementation Method 5
The composite membrane achieves high recovery efficiency of precious metal ions
Implementation Method 6
improved oil-water separation, with synergistic enhancement in both processes
Data Source
AI summary
A method for preparing a functional membrane for recovering precious metal ions from oily wastewater is provided. The method includes: obtaining carbon nanotubes functionalized by polyacrylic acid (CNTs-PAA) by grafting acrylic acid onto a surface of carbon nanotubes (CNTs) via graft polymerization; obtaining carbon nanotubes modified by acyl hydrazine functional groups (CNTs-PAH) by reacting adipic dihydrazide (ADH) with carboxyl functional groups of the CNTs-PAA; preparing single-layer MXene nanosheets using Ti3AlC2 powder; and preparing a CNTs-PAH/MXene composite membrane by vacuum filtration based on the CNTs-PAH and the single-layer Mxene nanosheets.