European legislative drivers are also encouraging the increased use of this technology in the treatment of landfill leachate. NF bridges the gap between RO and UF, and is commonly used for desalting and concentration duties in the textile industry. A wide range of industrial applications use UF because its versatile nature lends itself to separating flows as diverse as effluent streams from dye houses and pulp mills to fruit juice clarification. At the higher end of the spectrum as we move towards MF, ceramic membranes are often used to provide a wide range of pore sizes in the food and drink, pharmaceutical and chemical industries as well as for separating wastewater effluents. A selection of PCI Memtech's membrane products.
Polymeric membranes account for the biggest proportion of membranes currently in use.
Several different polymers are used to suit the molecular weight cut off required or to achieve the desired resistance to fouling or performance when in contact with specific process fluids. Common polymers include polysulphone and polyethersulphone, which are used for the full range of UF membranes. Although cellulose acetate, the first widely used polymer, is still used in certain applications where it exhibits superior fouling characteristics, its use is limited due to its tendency to hydrolyse in alkaline conditions. Membranes can be configured in tubular, spiral, flat sheet or hollow fibre arrangements. Tubular membranes have several advantages.