Ultrafiltration (UF) is also a pressure difference as the driving force of the membrane separation process, is generally considered ultrafiltration is a sieve separation process. The solvent in the raw material solution and the small solute particles are transferred from the high-pressure liquid-liquid side to the low-pressure side by the pressure difference, and the resulting liquid is generally referred to as a filtrate or a permeated liquid, Sub-film retained, so that it increased in the concentration of the remaining solution to achieve the purpose of solution purification, separation and concentration. China in the 20th century, 80 years of successful development of the technology.
Ultrafiltration technology features:
Ultrafiltration membrane early use of cellulose acetate membrane material, later also with polysulfone, polyether sulfone, polypropylene wax, polyvinyl chloride, polyvinylidene deuteride, vinyl chloride, and inorganic membrane materials. The membrane has a pore size of about 0.002 to 0.1 μm and a molecular weight of about 500 to 500,000.
Its operating pressure in the 0.07-0.7Mpa or so.
Ultrafiltration process has the following characteristics:
(1) the process without phase change, can be carried out at room temperature and low pressure and thus low energy consumption;
(2) substances in the concentration process of separation does not occur qualitative changes, suitable for heat-sensitive substances;
(3) can be different molecular weight of the material classification separation;
(4) in the process of ultrafiltration membrane without impurities off to ensure that the ultrafiltration filtrate pure.
Ultrafiltration technology on the field:
(1) the electronics industry: semiconductor industry, ultra-pure water, integrated circuit cleaning water terminal treatment;
(2) pharmaceutical industry: medical pure water sterilization, in addition to pyrogen, drug concentration separation;
(3) food industry: fruit juice concentrate clarification, protein concentration, enzyme preparation concentration;
(4) water treatment works: mineral water preparation, drinking water purification, and ultrafiltration as a reverse osmosis pretreatment;
(5) wastewater treatment works: industrial wastewater treatment, municipal wastewater treatment reuse;
(6) textile industry: the recovery of fiber processing oil, scouring waste in the recovery of lanolin