Gravity-Driven Water Filter with Nanofibrous Composite Membrane
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current water filtration technologies for outdoor and emergency situations face limitations due to low porosity, high energy consumption, and low rejection performance, making them unsuitable for portable and gravity-driven applications, especially in providing safe drinking water from contaminated sources.
Innovation Solution
A novel hand-carry, gravity-driven water filter using a composite nanofibrous membrane with interwoven structures and surface-loaded silver nanoparticles, which offers high throughput, effective contaminant removal, and disinfection capabilities without the need for electricity, utilizing electrospun or non-solvent induced phase separation methods for membrane fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If phase inversion method membranes are used for water filtration, then the filter structure is simple and easy to manufacture, but the porosity is low and mass transfer resistance is high, limiting throughput
Solution Approach 1:
The patent uses nanofiber membranes with inherently high porosity (50-90%) compared to conventional phase inversion membranes. The nanofiber structure creates numerous interconnected pores that allow high water flux while maintaining filtration capability, directly resolving the throughput limitation without complicating manufacturing.
Solution Approach 2:
The patent employs composite membrane structures combining nanofibers with other materials (e.g., metal oxides, polymers) to achieve both high porosity and enhanced filtration performance. This composite approach maintains manufacturing feasibility while dramatically improving water throughput and contaminant rejection.
2Reliability
If reverse osmosis or nanofiltration membranes are used, then contaminant removal performance is high, but high pressure is needed resulting in high energy consumption
Solution Approach 1:
The patent changes the operating pressure parameter from high (reverse osmosis) to low or atmospheric pressure by using nanofiber membrane structures with optimized pore sizes (1-100 nm). This allows achieving high contaminant removal without the energy-intensive high pressure requirements of conventional RO/NF systems.
Solution Approach 2:
The patent replaces the mechanical pressure-driven system with a gravity-driven or low-pressure system using nanofiber membranes. The unique nanofiber structure provides high rejection performance through physical sieving and surface interactions rather than relying on high mechanical pressure, significantly reducing energy consumption.
3Use of energy by moving object
If ultrafiltration or microfiltration membranes are used, then low external pressure is needed, but rejection performance is low limiting outdoor application
Solution Approach 1:
The patent uses nanofiber membranes with precisely controlled pore sizes (1-100 nm) that are smaller than conventional UF/MF membranes. This nanoscale porosity enables high rejection of pathogens and contaminants while maintaining low pressure requirements, bridging the gap between energy efficiency and filtration performance.
Solution Approach 2:
The patent applies local quality enhancement by modifying specific regions of the membrane or using nanofibers with localized functional properties (e.g., surface charge, hydrophobicity) to achieve high rejection performance in specific areas while maintaining overall low-pressure operation and high throughput.
4Productivity
If nanofiber-based membranes with high porosity are used, then water throughput is significantly improved, but device complexity increases
Solution Approach 1:
The patent utilizes the inherent porosity of nanofiber materials to achieve high water throughput. The nanofiber structure naturally provides interconnected pores without requiring complex multi-layer constructions, maintaining relative device simplicity while maximizing water flux through the membrane.
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 filter effectively removes a wide range of contaminants, including pathogens, suspended solids, and heavy metals, providing safe drinking water and exhibiting antifouling and antimicrobial properties, with enhanced water throughput and disinfection performance, suitable for outdoor and emergency use.
Implementation Method 1
a first nanofibrous membrane... a second nanofibrous membrane
Implementation Method 2
The water filter... with high throughput and water disinfection performance... Silver nanoparticles may be loaded in-situ on the surface of the membrane to provide for water disinfection
Implementation Method 3
gravity-driven (or mechanically-enhanced) water filter... the purification process can be carried out under the force of gravity
Data Source
AI summary
A hand-carry gravity-driven water filter with high throughput and water disinfection performance is formed. Membranes used for this water filter can be fabricated using electrospun method and non-solvent induced phase inversion method. A novel composite membrane structure (interwoven composite structure) was designed for further enhances water permeability and mechanical strength. The composite membrane can be composed of nanofibers with different diameter from the same polymer or different polymers. Membrane porosity and surface pore size can be controlled. Silver nanoparticles can be in-situ loaded on the surface of the membranes. The developed filter is effective for removal of a wide range of contaminants (e.g., pathogens, suspended solids and heavy metals). The purification process can be carried out under the drive of gravity (with an option for mechanically-enhanced filtration) without electricity.