A Uniform Particle Size, High Capacity, Strong Base Anion Exchange Resin for Demineralization Applications

Product Type Matrix Functional group
DOWEX* MARATHON* A Type 1 strong base anion Styrene-DVB, gel Quaternary amine
Guaranteed Sales Specifications CI-form OH- form
Total exchange capacity, min. eq/I 1.3 1
kgr/ft3 as CaCO3 28.4 21.9
Water content % 50-60 60-72
Uniformity coefficient, max. 1.1 1.1
Typical Physical and Chemical Properties CI-form OH- form
Mean particle size+ pm 575±50 610 ± 50
Whole uncracked beads % 95-100 95-100
Total swelling (CI- OH-) % 20 20
Particle density g/ml 1.08 1.06
Shipping Weight g/l 670 640
Ibs/ft3 42 40
Recommended Operating Conditions
Maximum operating temperature:
OH- form 60°C (140°F)
CI- form 100°C (212°F)
pH range 0-14
Bed depth, min. 800 mm (2.6 ft)
Flow rates:
Service/fast rinse 5-60 m/h (2-24 gpm/ft2)
Backwash See figure 1
Co-current regeneration/displacement rinse 1-10 mlh (0.4-4 gpm/ft2)
Counter-current regeneration/displacement rinse 5-20 m/h (2-8 gpm/ft2)
Total rinse requirement 3-6 Bed volumes
Type 2-5% NaOH
Temperature Ambient or up to 50°C (122°F) for silica removal
Organic loading, max. 3g KMnO4/I resin

+For additional particle size information, please refer to the Particle Size Distribution Cross

Reference Chart (Form No. 177-01775/CH 171-476-E).

Typical properties and applications:

DOWEX’ MARATHON” A anion exchange resin is specifically designed to give high throughput and economical operation in primary demineralizer beds. Because of its uniform particle size, this resin offers a number of economic advantages over conventional (polydispersed) resins. The small uniform bead size of DOWEX MARATHON A resin results in rapid exchange kinetics during operation, more complete regeneration of the resin, and faster, more thorough

rinse following regeneration. It can be used for all types of water but especially for waters that have a high percentage of silica and carbon dioxide.


25 liter bags or 5 cubic feet fiber drums.

Figure 1. Backwash Expansion Data Figure 2. Pressure Drop Data
For other temperatures use: For other temperatures use:
FT = F77°F (1+ 0.008 (T°F -77)], where F =_ gpm/it2 PT = P20°c / (0.026 T°c + 0.48), where P =_ bar/m
FT= F25°C [1+ 0.008 (1.8T°c - 45)], where F =_ m/h PT = P68°F / (0.014 T°F + 0.05), where P =_ psi/ft

Warning: Oxidizing agents such as nitric acid attack organic ion exchange resins under certain conditions. This could lead to anything from slight resin degradation to a violent exothermic reaction (explosion). Before using strong oxidizing agents, consult sources knowledgeable in handling such materials.

Notice: No freedom from any patent owned by Seller or others is to be inferred. Because use conditions and applicable laws may differ from one location to another and may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customer’s use and for ensuring that Customer’s workplace and disposal practices are in compliance with applicable laws and other governmental enactments. Seller assumes no obligation or liability for the information in this document. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MEf3CHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.

Published September 1998.