Membranes in biodegradability of organic compounds

Abstract

Consulta en la Biblioteca ETSI Industriales (8332)

[eng+ A membrane is a layer of material which serves as a selective barrier between two phases and remains impermeable to specific particles, molecules, or substances when exposed to the action of a driving force. Some components are allowed passage by the membrane into a permeate stream, whereas others are retained by it and accumulate in the retentate stream. According to their size, membranes can be of various thickness, with homogeneous or heterogeneous structure. They can also be classified according to their pore diameter. According to IUPAC, there are three different types of pore size (dp) classifications: - Microporous ¿ dp < 2nm - Mesoporous ¿ 2nm < dp < 50nm - Macroporous ¿ dp > 50nm Referring to membrane¿s history, they have two basic and independent histories: - Microporous membranes became commercial in Germany in small quantities prior to WW II. - Reverse Osmosis membranas were originally developed, from cellulose acetate, in the early 1960's at the University of California as a means to desalinate seawater. The late 1960's and 70's saw the formation of most of today's best-known and largest membrane manufacturing companies. Membranes can be neutral or charged, and particles transport can be active or passive. The latter can be facilitated by pressure, concentration, chemical or electrical gradients of the membrane process. Membranes can be generally classified into three groups: inorganic, polymeric or biological membranes. These three types of membranes differ significantly in their structure, but what it is studied in this project are the polymeric membranes.