Development of Anti-Scaling membranes for Desalination

Reverse osmosis is considered the most optimized membrane-based process utilized for desalination and water reuse. Despite its global implementation, scaling mitigation, in particular gypsum remains challenging. Consequently, it leads to several operational problems including increased feed channel pressure, decreased permeate flux, permeate quality deterioration, frequent membrane cleaning, and its periodic replacement.

The affinity of the Ca⁺ towards the carboxyl groups for making complexes makes the polyamide RO membrane more susceptible to scaling. These interactions increased Ca²⁺ concentration thus initiating pre-nucleation and subsequent amorphous nanostructures formation over the surface.

Later, these amorphous nanostructures serve as a template and grow by adding/hosting other ions from the solution to form the crystalline structure over the membrane surface.

This study highlights the role of modified surface chemistry in preventing scaling. The suppression of carboxyl groups together with improved surface roughness/hydrophilicity synergistically enhanced anti-scaling properties. The proposed approach provides a unified solution to overcome the fouling and selectivity challenges of RO thus making the process more sustainable and cost-effective.