Unlike Conventional EDI, FEDI Stacks Are Able to Tolerate Hardness in The Feed Water

Membrane manufacturer QUA has introduced its FEDI fractional electrodionization and Q-SEP hollow fibre ultrafiltration modules to the Southeast Asia water treatment market at Aquatech India. The FEDI technology from QUA has patented dual voltage and is an improvement on EDI for the production of high purity water for power and semiconductor applications. Unlike conventional EDI, FEDI stacks are able to tolerate hardness in the feed water. As a result, FEDI can be used after single pass RO without the need for softening, or second pass RO, on most feed waters. Each FEDI stack is equipped with two sets of electrodes. FEDI’s dual voltage technology allows for a higher flexibility to meet inlet water conditions, thus lowering the risk of scaling and improving reliability. Hardness and the majority of the other ions are removed in the bottom of the stack at low current density and low scaling conditions, while the final product water polishing takes place in the top of the stack at high current density. Q-SEP hollow fibre ultrafiltration modules contain membranes manufactured with QUA’s ‘Cloud Point Precipitation’ method. This process ensures a high pore density along the length of the fibre and uniform pore size distribution in the membrane. Q-SEP modules can produce water quality that is better than that produced from conventional UF modules, with low silt density index (SDI) and rejection of bacteria and viruses, the company says. Q-SEP modules are made from a hydrophilic polyether sulphone (PES) material that provides high fibre strength and low fouling characteristics. The hollow fibre membranes operate under low trans-membrane pressure in an inside-out flow configuration. Applications of Q-SEP include pre-treatment to reverse osmosis (RO) systems (brackish and seawater applications), purification of surface and well water for potable applications, filtration of industrial water, and wastewater recycle and reuse. Source: workingwithwater.filtsep.com