Development of Modified Reverse Osmosis Membrane with Polymers/Graphene Oxide for Scaling and Biofouling Mitigation

The increasing demand for freshwater, coupled with challenges posed by industrialization and climate change, has reinforced the need for efficient desalination technologies. Reverse osmosis (RO) is widely used due to its energy efficiency; however, operational challenges such as scaling and biofouling hinder membrane performance, reducing water flux and increasing maintenance costs. This study uniquely explored, the dual antifouling and antibiofouling properties of polymaleic acid (PMA) in an RO system. PMA was applied in two forms: as a membrane coating (ESPA2-PMA) and as an anti-scalant in the feed solution (ESPA2-PMA_Solution), with both methods tested under dynamic RO scaling, cleaning, and re-scaling conditions. Initial scaling experiments showed that both PMA applications reduced flux decline relative to the unmodified membrane. PMA in solution demonstrated the highest scaling resistance, maintaining up to 70% of initial flux after 6 hours, while the coated membrane showed moderate improvement. XPS analysis revealed that PMA’s form—coating versus solution—significantly influenced calcium (Ca) binding modes and even gypsum crystal formation process. In biofouling experiments, PMA coatings decreased biofilm coverage significantly, with ESPA2-PMA reducing Vibrio fischeri biofilm growth by 40% compared to unmodified membranes. The addition of GO into the PMA matrix further enhanced biofilm resistance, reducing biofilm formation by over 60%. Notably, this is the first study to demonstrate the antibacterial and antibiofouling efficacy of PMA in an RO system, establishing PMA as a multifunctional agent for membrane protection. Furthermore, ESPA-PMA-GO nanocomposite coatings were synthesized via a facile, one-step aqueous solution-based method. The ESPA-PMA-GO coated membranes exhibited higher water permeability (2.6 L/m²·h·bar) compared to the unmodified ESPA2 membranes (1.4 L/m²·h·bar), with no impact on salt rejection performance. These findings underscore the noteworthy potential of PMA-based strategies, including the combination with GO to address critical RO membranes challenges of scaling, biofouling and water flux efficiency.

Name thesis:degree_name

Doctor of Philosophy

Discipline thesis:degree_discipline

Environmental Engineering

Grantor

University of Houston

Year dc:date.issued

2024

Author dc:creator

• Silva Jacovone, Raynara Maria 1993-

Advisor dc:contributor.advisor

• Rodrigues, Debora F.

Committee members dc:contributor.committeemember

• Teixeira, Antonio Carlos
• Sakata, Solange
• Rexey, Willian
• Shaffer, Devin

Language dc:language.iso

English

Handle dc:identifier.uri

https://hdl.handle.net/10657/18371

OAI identifier oai:identifier

oai:uh-ir.tdl.org:10657/18371