Electrospun Nanostructured Membrane Engineering Using Reverse Osmosis Recycled Modules: Membrane Distillation...

Area of Science:

• Materials Science
• Environmental Engineering
• Chemical Engineering

Background:

• Growing number of discarded reverse osmosis (RO) modules pose a significant waste management challenge.
• Current disposal methods for RO modules involve landfilling, contributing to environmental pollution.
• Need for sustainable solutions to manage end-of-life RO components.

Purpose of the Study:

• To investigate the recycling and reuse of internal components from discarded RO modules.
• To engineer novel membranes for membrane distillation (MD) technology using these recycled materials.
• To evaluate the performance of these recycled components as supports for electrospun nanofibrous membranes in desalination.

Main Methods:

• Passive cleaning of discarded RO membranes and spacers using a sodium hypochlorite solution.
• Reuse of cleaned components as supports for polyvinylidene fluoride (PVDF) nanofibrous membranes fabricated via electrospinning.
• Characterization of the prepared membranes and testing in direct contact membrane distillation (DCMD) for high saline solution desalination.

Main Results:

• Recycled RO membranes and permeate spacers, when used as supports with 60 min electrospinning, yielded high permeate fluxes (43.2 and 18.1 kg m⁻² h⁻¹, respectively).
• Exceptional salt rejection factors exceeding 99.99% were achieved with these recycled supports.
• Using the feed spacer as a support resulted in inhomogeneous structures, leading to poor salt rejection and mechanical properties.

Conclusions:

• Recycling RO membranes and spacers provides a viable and sustainable pathway for creating effective support layers for MD membranes.
• The developed membranes demonstrate competitive performance in DCMD desalination, comparable to existing supported and unsupported membranes.
• This research offers a promising approach to mitigate RO waste while advancing membrane distillation technology.