title: Chemical cleaning of fouled PVC membrane during ultrafiltration of algal-rich water.
abstract: Cleaning of hollow-fibre polyvinyl chloride (PVC) membrane with different chemical reagents after ultrafiltration of algal-rich water was investigated. Among the tested cleaning reagents (NaOH, HCl, EDTA, and NaClO), 100 mg/L NaClO exhibited the best performance (88.4% +/- 1.1%) in removing the irreversible fouling resistance. This might be attributed to the fact that NaClO could eliminate almost all the major foulants such as carbohydrate-like and protein-like materials on the membrane surface, as confirmed by Fourier transform infrared spectroscopy analysis. However, negligible irreversible resistance (1.5% +/- 1.0%) was obtained when the membrane was cleaning by 500 mg/L NaOH for 1.0 hr, although the NaOH solution could also desorb a portion of the major foulants from the fouled PVC membrane. Scanning electronic microscopy and atomic force microscopy analyses demonstrated that 500 mg/L NaOH could change the structure of the residual foulants on the membrane, making them more tightly attached to the membrane surface. This phenomenon might be responsible for the negligible membrane permeability restoration after NaOH cleaning. On the other hand, the microscopic analyses reflected that NaClO could effectively remove the foulants accumulated on the membrane surface.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. zhang.yan113@163.com
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jiayu
authors.initials: J
authors.lastname: Tian
authors.forename: Heng
authors.initials: H
authors.lastname: Liang
authors.forename: Jun
authors.initials: J
authors.lastname: Nan
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Chen
authors.forename: Guibai
authors.initials: G
authors.lastname: Li
mesh_terms: D057219:Biofouling / Q000517:prevention & control*; D056890:Eukaryota / Q000187:drug effects / Q000254:growth & development*; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D009930:Organic Chemicals / Q000032:analysis; D011143:Polyvinyl Chloride / Q000737:chemistry* / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D012973:Sodium Hypochlorite / Q000494:pharmacology; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties / Q000187:drug effects; D014462:Ultrafiltration / Q000379:methods*; D014867:Water / Q000469:parasitology*; D018508:Water Purification / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D009930:Organic Chemicals; D012996:Solutions; D014867:Water; D012965:Sodium Chloride; D011143:Polyvinyl Chloride; D012973:Sodium Hypochlorite