Copolymer Filtration for Selenium Removal
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Solution Overview
Problem
Current methods for removing heavy metals from industrial wastewater, such as those using dithiocarbamate chemistries or ultrafiltration/microfiltration membranes, are inadequate for achieving stringent metal discharge limits, particularly in the ppb or ppt concentration range, and lack effective solutions for selenium removal.
Innovation Solution
A method involving the use of a copolymer derived from acrylic-x and alkylamine monomers, which is treated with a filter to scavenge metals, including selenium, utilizing a dithiocarbamate salt group functionalization and various filtration techniques like ultrafiltration, nanofiltration, or reverse osmosis to achieve effective metal removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional dithiocarbamate chemistries or ultrafiltration/microfiltration membranes are used for metal removal, then the treatment process is relatively simple and compact, but the metal removal efficiency is insufficient to meet stringent discharge limits in the ppb or ppt concentration range
Solution Approach 1:
The patent employs a composite treatment approach combining polymeric dithiocarbamate compounds with advanced filtration membranes (nanofiltration or reverse osmosis). This composite system integrates chemical precipitation capabilities with physical filtration to achieve metal removal at ppb/ppt levels, resolving the contradiction between removal efficiency and process complexity by synergistically combining multiple treatment mechanisms.
Solution Approach 2:
The patent utilizes pH adjustment as a critical parameter change to optimize metal removal efficiency. By controlling pH levels during the treatment process, the polymeric dithiocarbamate compounds effectively precipitate metals, and the filtration system achieves stringent discharge limits. This parameter optimization enables high removal efficiency without proportionally increasing system complexity.
2Manufacturing precision
If conventional clarification methods are used for solid-liquid separation, then the process is simpler, but the water quality is inferior with higher suspended solids and turbidity
Solution Approach 1:
The patent employs porous filtration membranes (nanofiltration or reverse osmosis) instead of conventional clarification. These porous materials provide physical barriers that effectively remove suspended solids and reduce turbidity to negligible levels, producing high-quality water suitable for reuse. The porous structure enables superior separation performance while maintaining a compact system design.
Solution Approach 2:
The use of thin-film filtration membranes replaces bulk clarification systems. These flexible thin-film barriers provide efficient solid-liquid separation with minimal footprint, achieving superior water quality (almost no suspended solids and negligible turbidity) while maintaining system compactness and operational simplicity.
3Manufacturing precision
If membrane filtration is used for solid-liquid separation, then water quality is very high with almost no suspended solids, but the system is less compact and requires more complex operation
Solution Approach 1:
The patent implements preliminary chemical treatment using polymeric dithiocarbamate compounds to precipitate metals before filtration. This preliminary action reduces the burden on the membrane filtration system, allowing it to operate more efficiently with less fouling and simpler maintenance. The pre-precipitation step simplifies overall operation while maintaining superior water quality output.
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 results in a synergistic effect that surpasses the sum of its parts, effectively removing both large and small metal complex particles, including those that would otherwise remain in the water, thereby meeting stringent discharge limits and improving water quality.
Implementation Method 1
treating said medium containing selenium with a composition comprising a copolymer derived from at least two monomers: acrylic-x and an alkylamine
Implementation Method 2
passing the treated medium through a filter
Implementation Method 3
a copolymer derived from at least two monomers: acrylic-x and an alkylamine... The functional group may be a dithiocarbamate salt group
Data Source
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AI summary
The invention provides methods and compositions for separating metals from a liquid medium, the method uses a copolymer derived from at least two monomers: acrylic-x and an alkylamine, wherein said polymer is modified to contain a functional group capable of scavenging one or more compositions containing one or more metals are disclosed. The treated liquid is then passed through a filtration system. The scavenging effect of the combination of the treatment with the filtration is unexpectedly greater than the sum of its parts. MS