Languages Locations MSDS/SDS Contact Us Core Technologies Healthcare & Life Sciences Company Selecting Resins Resistant To Organic Fouling / Core Technologies / Purolite Selecting Resins Resistant to Organic Fouling Here to Help Our always-ready technical support and service teams go the extra step to be your most trusted resource. We're here for you. CONTACT US OVERVIEW Selecting Resins Resistant to Organic Fouling Organic Fouling Naturally occurring dissolved organics collectively measured as TOC (Total Organic Carbon), COD (Chemical Oxygen Demand) or BOD (Biological Oxygen Demand) can foul and affect the performance of ion exchange demineralization plants. This kind of problem is normally associated with plants that treat surface waters which contain either naturally occurring or synthetic organics. Manmade organic material normally enters the supply via drains as the rivers pass through towns or industrial areas. In all cases these organic fouling materials have a large molecular weight and are usually hydrophobic in nature. The naturally occurring organics are often referred to generally as Humates and Fulvates. These large, complex organic molecules are attracted and captured on ion exchange resins, resulting in irreversible fouling, particularly of strong base anion resins. Organic fouling occurs on anion exchange resins because: Organics accumulate on the resin by ion exchange and physical (Van der Waal’s) forces Exchange sites become blocked by the accumulated organics When organic fouling occurs, there will be a reduction in demineralization plant efficiency overall. The speed of ion exchange especially for multivalent anions like sulfate is slowed down (kinetic impairment). Long alkaline rinses after caustic regeneration are typically encountered due to slow hydrolysis of sodium off the accumulated organic foulants. As a consequence, the treated water quality will be reduced with higher conductivity and higher silica and sodium leakages. The operating costs will increase, due to shorter cycles and higher rinse water and regenerant requirements. In general, anion exchange resins remove natural organic matter (NOM) from water particularly well, but unless care is taken in the selection of the anion exchange resin plus in certain cases the correct pretreatment process, rapid fouling of the resin can occur, and this fouling is often irreversible. Organic Scavengers The best organic scavenger resins normally have a macroporous structure (though some gel scavenger resins do exist) and they are normally manufactured from either polystyrenic or polyacrylic polymers. The Purolite macroporous, polystyrenic based product is Purolite A502P and the macroporous, polyacrylic based product is Purolite A860. Food grade versions A502PS and A860S are also available and widely used in the food industry and potable water applications. In general terms the polyacrylic based resin often offers a greater reversible removal of organics on regeneration (due to their more hydrophilic structure) and can therefore often cope better with higher levels of dissolved organics. The polystyrenic resin can often reduce dissolved organics down to lower levels, but it is less easy to regenerate (more hydrophobic structure) and so can be more prone to irreversible fouling. Due to their different structures and slightly different performance many plants now include a combination of both these resins, with a 50:50 ratio employed. Using a bed containing two different polymer structures frequently offers the best removal of organics. When used together in a single column in a conventional co‑flow regenerated plant the Purolite A502P is loaded first into the bottom of the unit with the Purolite A860 on top. Some mixing will inevitably occur, but there is an advantage in having the water passing through the polyacrylic resin first as this portion of the bed will see the higher organic loading. If you have any questions regarding Organic Fouling or Organic Scavenger products, please contact your local Purolite office or fill out our Contact Us form. Organics Removal Products by Application DEMINERALIZATION - HIGH ORGANICS WATER NATURAL ORGANIC MATTER (NOM) REMOVAL ORGANIC SCAVENGER Here to Help Solve Your Most Complex Challenges FIND A SPECIALIST .st0{fill:#231F20;} .st1{fill:#00AEEF;} © 2021 Purolite. This site is protected by copyright and trademark laws under U.S. and International law. All Rights Reserved. About Purolite Core Technologies Healthcare & Life Sciences News Blog Events Contact Us Locations Careers AMERICAS T +1 610 595 4689 EMEA T +44 1443 229334 ASIA PACIFIC T +86 571 876 31382 FSU T +7 495 363 5056 TERMS AND CONDITIONS PRIVACY POLICY MODERN SLAVERY STATEMENT PRSM TERMS OF USE