University of Illinois Urbana-Champaign

Changes in the structure of SW30HR RO membrane exposed to chloraminated seawater and synthetic solutions

Renkens, Tennie

Content Files
Renkens_Tennie.pdf

Permalink

https://hdl.handle.net/2142/31985

Description

Title
Changes in the structure of SW30HR RO membrane exposed to chloraminated seawater and synthetic solutions
Author(s)
Renkens, Tennie
Issue Date
2012-06-27T21:23:10Z
Director of Research (if dissertation) or Advisor (if thesis)
Mariñas, Benito J.
Department of Study
Civil & Environmental Eng
Discipline
Environ Engr in Civil Engr
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Date of Ingest
2012-06-27T21:23:10Z
Keyword(s)
  • reverse osmosis membrane
  • fouling
  • halogenation
Abstract
Changes in the structure of the SW30HR RO membrane exposed to seawater, phosphate buffer, and standard seawater disinfected with monochloramine (NH2Cl) are investigated. Three types of experiments were performed: (1) exposure of RO membrane (active and support layers) to monochloramine (2, 20 and 200 mg/L as Cl2) and target proportional levels of iodide (0.06, 0.6 and 6 mg/L) or bromide (60, 600 and 6,000 mg/L) at constant exposure CT=384 mg×h/L; (2) exposure of support layer only to monochloramine at CT values of 1,000 and 30,000 mg×h/L at a monochloramine concentration of 200 mg/L as Cl2; (3) exposure of RO membrane (active and support layers) to monochloramine at CT values of 1,000, 5,000 and 30,000 mg×h/L at a monochloramine concentration of 200 mg/L as Cl2 in the presence of only 6 mg/L of iodide, only 6,000 mg/L of bromide, and both 6 mg/L of iodide and 6,000 mg/L of bromide. Results revealed that monochloramine may be reacting with the polysulfone support of RO membranes. RBS analyses have revealed that the RO membrane support might undergo damage. Recent work involves determining the effect of active layer-bound halogens on carboxylic group accessibility. Cesium (Cs+), silver (Ag+), and barium (Ba2+) were used as ion probes to quantify the changes associated with membranes exposed to three different batch reactor conditions (1) seawater with 2 ppm NH2Cl; (2) phosphate buffer with 2 ppm NH2Cl and 65 mg/L KBr as Br-; (3) standard seawater with 2 ppm NH2Cl and 65 mg/L KBr as Br-. Preliminary results indicate a shift in the pKa values of active layer carboxylic groups in batch reactors containing NH2Cl in comparison to control reactors.
Graduation Semester
2012-05
Permalink
http://hdl.handle.net/2142/31985
Copyright and License Information
Copyright 2012 Tennie Renkens

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