TY - GEN
T1 - Postsynthesis modification of a cellulose acetate ultrafiltration membrane for applications in water and wastewater treatment
AU - Morão, A.
AU - Escobar, I. C.
AU - De Amorim, M. T.Pessoa
AU - Lopes, A.
AU - Gonçalves, I. C.
PY - 2005/12
Y1 - 2005/12
N2 - A technique for postsynthesis modification of a cellulose acetate ultrafiltration membrane with possible application in water and wastewater treatment is studied. The technique used an oxidizing agent (persul-fate) to develop free radicals on the membrane surface, and that was expected to promote grafting of hydrophilic macromolecules (polyethylene glycol). A chain-transfer agent (2-mercaptoethanol) was tested to control the grafting process, avoiding the formation of long chains that usually lead to high permeability losses in other graft techniques. The modifications aimed at the decrease of the fouling susceptibility of the membrane studied. The possibility of an increase in rejection was also investigated. The membrane was characterized before and after modification, by attenuated total reflectance-Fourier transform-infrared spectroscopy, scanning electron microscopy, atomic force microscopy, and in terms of the rejection of neutral reference solutes. The information given by the different techniques of characterization provided strong evidences of the occurrence of modification, although permeation of (real) foulants was the decisive test. To obtain information about the fouling tendency of the nonmodified and modified membranes, two different kinds of foulants were used: a humic acid (usually found in surface waters) and textile auxiliaries (representing one of the most important industries in Portugal). The results showed an increase in the rejections of the humic acid, and significant improvements in the performance of the membrane with respect to fouling tendency in the case of the textile auxiliaries.
AB - A technique for postsynthesis modification of a cellulose acetate ultrafiltration membrane with possible application in water and wastewater treatment is studied. The technique used an oxidizing agent (persul-fate) to develop free radicals on the membrane surface, and that was expected to promote grafting of hydrophilic macromolecules (polyethylene glycol). A chain-transfer agent (2-mercaptoethanol) was tested to control the grafting process, avoiding the formation of long chains that usually lead to high permeability losses in other graft techniques. The modifications aimed at the decrease of the fouling susceptibility of the membrane studied. The possibility of an increase in rejection was also investigated. The membrane was characterized before and after modification, by attenuated total reflectance-Fourier transform-infrared spectroscopy, scanning electron microscopy, atomic force microscopy, and in terms of the rejection of neutral reference solutes. The information given by the different techniques of characterization provided strong evidences of the occurrence of modification, although permeation of (real) foulants was the decisive test. To obtain information about the fouling tendency of the nonmodified and modified membranes, two different kinds of foulants were used: a humic acid (usually found in surface waters) and textile auxiliaries (representing one of the most important industries in Portugal). The results showed an increase in the rejections of the humic acid, and significant improvements in the performance of the membrane with respect to fouling tendency in the case of the textile auxiliaries.
KW - Cellulose acetate
KW - Fouling
KW - Grafting
KW - Textile
KW - Ultrafiltration
UR - http://www.scopus.com/inward/record.url?scp=33646822641&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33646822641&partnerID=8YFLogxK
U2 - 10.1002/ep.10107
DO - 10.1002/ep.10107
M3 - Article
AN - SCOPUS:33646822641
SN - 0278-4491
VL - 24
SP - 367
EP - 382
JO - Environmental Progress
JF - Environmental Progress
ER -