Optimum RO system design with high area spiral-wound elements

Abstract

The membrane and spiral wound elements used for seawater desalination continue to evolve, particularly in regards to lowering energy costs. Most recently, high area elements and ultra low pressure seawater reverse osmosis (SWRO) elements have come onto the market. Laboratory and pilot testing of these elements demonstrate that they can achieve both high rejection and low pressure operation. Use of these high performance SWRO products is a challenge, however. Detailed analysis indicates that the higher permeability membranes have a greater flux imbalance in the process, but there are ways to take advantage of these capabilities with proper system design. An example of the use of high area seawater membranes will be presented. It shows that significant capital savings can be achieved. Using high area elements to run at lower flux is also possible, but the economic gain is only realized when operating a one pass system.

Review of membrane distillation process for water purification

“…Some of the researchers designed new techniques for the generation of MD membranes using different types of SMMs, other polymers, solvents, additives for growth in the MD performance. Some of these are co-polymers like polyvinylidenefluoride-hexafluoropropylene (PVDF-HFP) and polyvinylidenefluoride-tetrafluoroethylene (PVDF-TFE) [107][108][109][110][111], the fabricated Polyethersulfone (PES) and Polysulfone (PS) [112][113][114][115], new hydrophobic poly (phthalazinone ether sulfone ketone) hollow fiber composite membranes coated with silicon rubber and with sol-gel polytrifluoropropylsiloxane [4], nanofiber membranes [116], carbon nanotube bucky-paper membranes [117][118][119], carbon nanotube (CNT)-based composite materials [120], oxidized (using HNO 3 and H 2 SO 4 ) carbon nanotube [121], and mixed matrix PVDF [122].…”

“…Membrane technologies such as micro filtration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), and membrane distillation (MD) have become more attractive for water treatment when compared to conventional purification [1][2][3]. Among these membrane technologies, MF, UF, NF, and RO is the pressure-driven separation technologies and only MD is a thermal-driven separation process [1,4].…”

Molecular Scale Modeling of Membrane Water Treatment Processes

“…The effects of membrane fouling are detected as a reduction in the efficiency of the RO process, as reflected in higher operating pressures and lower permeate fluxes. This is due to the fact that membrane fouling is generally caused by the adsorption of solutes to the membrane surface, as well as pore clogging (in porous membranes) [93]. Such fouling mechanisms effectively reduce the membrane surface area.…”