Atmospheric pressure atomic layer deposition for tight ceramic nanofiltration membranes: Synthesis and application in water purification

Tight ceramic nanofiltration (NF) membranes allow efficient separation of organic matter and ions for advanced water treatment. These membranes are typically produced by the sol-gel method. Recently, atomic layer deposition (ALD), a self-limiting gas phase coating technique, has been explored for membrane fabrication and modification. In this...

Fundamental fouling mechanisms of dissolved organic matter fractions and their implications on the surface modifications of ceramic nanofiltration membranes: insights from a laboratory scale application

This work reports on the fundamental factors influencing inter-foulant and foulant-membrane interactions during simulated dissolved organic matter removal using ceramic nanofiltration. Fouling tests were performed using sodium alginate (SAL), humic acid (HA) and bovine serum albumin (BSA) as model foulants. Fouling potentials of each foulant and...

Pilot-scale assessment of urea as a chemical cleaning agent for biofouling control in spiral-wound reverse osmosis membrane elements

Routine chemical cleaning with the combined use of sodium hydroxide (NaOH) and hydrochloric acid (HCl) is carried out as a means of biofouling control in reverse osmosis (RO) membranes. The novelty of the research presented herein is in the application of urea, instead of NaOH, as a chemical cleaning agent to full-scale spiral-wound RO...

As(V) rejection by NF membranes using high temperature sources for drinking water production

In Nicaragua, a Central American country, geothermally influenced waters are frequently found to be contaminated with arsenic (as As(V)). This study investigated the effect of high-temperatures (25–50 °C), as found in geothermally influenced source waters, on the rejection of monovalent H2AsO4 - and divalent HAsO4 2- species (at pH 6,7 and 8)...

Arsenic removal from geothermal influenced groundwater with low pressure NF pilot plant for drinking water production in Nicaraguan rural communities

This research evaluated the effect of different fluxes (16, 23 & 30 L/m ² h) and temperatures (31,35 & 43 °C) on the rejection of As(V) during nanofiltration (NF) of natural geothermal influenced groundwater in Nicaragua. A NF pilot plant powered by solar panels was built and operated in rural community Telica, exposed to...

Experimental and theoretical characterization of commercial nanofiltration membranes for the treatment of ion exchange spent regenerant

This work presents a joint experimental and simulation campaign aimed at characterizing two nanofiltration membranes (TS80 and NF270) in the presence of a multi-ionic water solution simulating the spent regenerant of cationic ion exchange resins employed for water softening. We identified the membrane parameters, which allowed for predicting...

Separation of natural organic matter and sodium chloride for salt recovery purposes in zero liquid discharge

The application of zero liquid discharge (ZLD) results in the generation of solid residual streams, which are often not fit for reuse. In this study, we assessed the separation of natural organic matter (NOM) and sodium chloride (NaCl) by nanofiltration (NF), electrodialysis (ED) and ion exchange (IEX) in reverse osmosis brine (RO-brine) and by...

Integration of oxalic acid chelation and Fenton process for synergistic relaxation-oxidation of persistent gel-like fouling of ceramic nanofiltration membranes

Ceramic nanofiltration (NF) is a newly-developed technology for water recycling, but is still limited to pilot-scale applications. Lacking efficient and eco-friendly strategies for cleaning ceramic NF membrane impedes its scaling-up in industries. Forward flush, backwash and acidic/caustic cleaning are not efficient enough. In this work, a...

Adsorption and cake layer fouling in relation to Fenton cleaning of ceramic nanofiltration membranes

Catalytic ceramic nanofiltration (NF) is a promising technology for direct wastewater reclamation, given its high separation selectivity and reactive surfaces for oxidative removal of fouling. A better understanding of the relation between fouling types and oxidative cleaning efficacy under high organic loading conditions is of practical...

Improved cleaning performance of membrane modules using feed spacers modified with cold-plasma treatment and polydopamine and silver-nanoparticle coatings

Membrane modules for seawater desalination are becoming increasingly important for obtaining clean water with the rising global water scarcity. The productivity of membrane modules is compromised by biofouling on the membrane and feed spacer. Biofouling development can be mitigated by modification of the spacer or membrane surface. The...