Chelating Resin ProBond™ CI
ProBond™ CI (Cation Iminodiacetate) (P/N ER10112) is a macroporous weak acid cation exchange resin which has chelating properties for heavy metal ions even against high concentrations of calcium. It is intended for use in polishing heavy metal ions from near neutral industrial wastes and process streams, and recovery of precious metals. It is supplied in the sodium form as moist, tough, uniform spherical beads.
ProBond CI is ideally suited for use in numerous applications including Waste Treatment, Chemical Processing, and Resource Recovery.
NOTE: Click on graphs below to enlarge.
ER10112 Pressure Drop Graph
PRESSURE DROP — The graph above shows the expected pressure loss per foot of bed depth as a function of flow rate at various temperatures.
ER10112 Backwash Graph
BACKWASH — After each cycle the resin bed should be backwashed at a rate that expands the bed 50 to 75 percent. This will remove any foreign matter and reclassify the bed.
The relative affinity of ProBond CI for heavy metals in near neutral solutions is in accordance with the following sequence.
H+1>> Cu+2> V+2>> (UO2)+2> Pb+2> Ni+2> Zn+2> Co+2> Cd+2> Fe+2> Be+2> Mn+2> Mg+2> Ca+2> Sr+2> Ba+2>> Na+1
High concentrations of chlorides or sulfates, or the presence of chelating or complexing agents can alter this sequence and likewise will affect the operating capacity.
High Chloride Solutions
Cu+2> Ni+2> Co+2> Zn+2> Cd+2> Fe+2
High Sulfate Solutions
Cu+2> Ni+2> Cd+2> Zn+2> Co+2> Fe+2
ProBond CI has similar chelating characteristics to EDTA and NTA. Therefore it is less effective when these agents are present.
For each particular metal cation there is a critical pH at which ProBond CI has optimum selectivity. For most metals this pH is approximately 4.0. As the pH decreases, so does the selectivity. At a pH of approximately 1.5, ProBond CI loses its ability to remove most metals. The minimum pH values for removal of some common metal ions are as follows:
Manganese 4.0
Iron 3.0
Zinc, Cobalt 2.7
Nickel 2.5
Copper 1.5
As the pH increases, selectivity also decreases. At a pH of 9.0 selectivity for most metals is about 10% of the selectivity at optimum pH. Above a pH of 9.0 many metals form anionic complexes and are no longer present in a form that can be removed by ProBond CI.
ProBond CI, like other chelating resins, has very slow kinetics. Optimum capacity is obtained when the service flow rate is limited to 0.5 to 1.0 gpm/cu.ft. Where extremely low leakage of metals is required, two columns of ProBond CI should be operated in series. The primary column can be fully exhausted, allowing the polishing column to protect against leakage. After regeneration, the order of the columns is reversed with the freshly regenerated column used as the polisher.
  Able to chelate heavy metals in metal finishing rinses  
  Able to chelate heavy metals ions in high calcium concentrations  
  Highly uniform particle size giving a low pressure drop while maintaining excellent kinetics  
  Superior physical stability  
Part Number ER10112
Polymer Structure Macroporous Styrene with DVB
Functional Group R–CH2–N(COOH)2
Ionic Form (as shipped) Sodium
Physical Form Spherical beads
Screen Size Distribution
  + 16 mesh (US Std.)
  – 50 mesh (US Std.)
16 to 50
< 5%
< 1%
pH Range 1.5 to 14
Sphericity > 95%
Water Retention
  Sodium Form
55 to 60%
Solubility Insoluble
Approx. Ship. Wt.
  Sodium Form
43 lb/cu.ft.
Swelling H– to Na– Form 20%
Total Capacity
  Sodium Form
> 1.1 meq/mL
Maximum Temperature
  Sodium Form
  Hydrogen Form
170°F (77°C)
140°F (60°C)
Maximum Free Chlorine None
Minimum Bed Depth 36 inches
Backwash Rate (See graph left) 50 to 75% bed expansion
Service Flow Rate 1 to 2 gpm/cu.ft.
Pressure Drop (See graph left)
Acid Regenerant Concentration 4 to 10%
Regenerant Flow Rate 0.25 to 0.5 gpm/cu.ft.
Regenerant Contact Time 30 minutes minimum
Regenerant Level
8.7 lb/cu.ft.
12.5 lb/cu.ft.
Displacement Rinse Rate Same as Regenerant Flow Rate
Displacement Rinse Volume 10 to 20 gal/cu.ft
Fast Rinse Rate 1 to 2 gpm/cu.ft.
Fast Rinse Volume Same as Service Flow Rate
Caustic Neutralization Concentration 4 to 10%
Caustic Solution Flow Rate 0.25 to 0.5 gpm/cu.ft.
Caustic Contact Time 30 minutes minimum
Caustic Dose Level 2.5 to 6.0 lb/cu.ft.
* CAUTION: DO NOT MIX ION EXCHANGE RESINS WITH STRONG OXIDIZING AGENTS. Nitric acid and other strong oxidizing agents can cause explosive reactions when mixed with organic materials such as ion exchange resins.
SWT Ion Exchange Resin Guide
This information has been gathered from standard materials and or test data that is believed to be accurate and reliable. Nothing herein shall be determined to be a warranty or representation expressed or implied with respect to the use of such information or the use of the goods described for any particular purpose alone or in combination with other goods or processes, or that their use does not conflict with existing patent rights. No license is granted to practice any patented invention. It is solely for your consideration, investigation and verification.
ProBond™ is a trademark of Safe Water Technologies, Inc.
Safe Water Technologies, Inc.
996 Bluff City Boulevard
Elgin, IL 60120 USA
Telephone: +1.847.888.6900
Facsimile: +1.847.888.6924

Last Updated: December 15, 2021