Dr. Saifur Rahaman Lab

 Emerging Materials & Technologies for Water

Nano-Composite Conductive Membranes


Ultrafiltration (UF) membrane technologies provide a high quality effluent and have been proven to be effective for the removal of larger pathogens such as protozoa and bacteria from water. However, viral removal is still a highly problematic issue. Additionally, ultrafiltration membranes are prone to fouling by natural organic matter (NOM), a common constituent of source waters. In order to achieve higher viral removal and/or inactivation, and to control membrane fouling we develop nano-composite conductive UF membranes and investigate their effectiveness in cross-flow, electrochemical-filtration units.

Anti-Fouling Reverse Osmosis Membranes.


Thin-film composite (TFC) membranes are considered the core of membrane-based technologies for desalination and wastewater reclamation due to superior salt retaining capacity and water permeability. However, these membranes are prone to fouling due to inherent surface physicochemical properties, which also inevitably result in increased operation costs and compromised membrane longevity.  In order to control membrane fouling, we develop novel membrane surface coatings via polyelectrolyte layer-by-layer (LBL) self-assembly, functionalized with biocidal nanoparticles and polymer brushes.

Osmotic Processes for Sustainable Water & Energy


Production of potable water and renewable energy through conversion of wastewater is a concept that shows promise in improving sustainability of municipal water and power supply systems. An emerging membrane-based technology, pressure retarded osmosis (PRO), can effectively treat wastewater while simultaneously generating power through exploitation of the salinity gradient by using a high-salinity synthetic draw solution. Success of PRO depends on three important aspects: suitable draw solutions, robust membranes and downstream separation of draw solutes from draw solutions. We investigate all three aspects in order to develop a PRO process which is more efficient and sustainable.

Nutrient Recovery from Animal Manure


Annually, over 40% of mined phosphorus (P) is lost through the disposal of animal manure. As phosphorus reserves continue to decline, and a growing world population increases demand of P for agricultural uses, there is a huge potential for developing efficient and cost-effective technologies for recovery of phosphorus from animal manure.  Already used in domestic sewage treatment, fluidized bed crystallization can be used to recover soluble P from manure as a commercially reusable compound such as struvite (MAP: MgNH4PO4•6H2O), a high-purity slow-release fertilizer. We investigate ultrasound assisted fluidized bed crystallization processes for maximizing nutrient recovery while minimizing environmental impacts posed by waste disposal from livestock industries.