Laserfiche WebLink
I. <br />Ion exchange resins are classified as cation or <br />exchangers. Both t anion <br />organic types are produced from the same basic <br />Polymers. The chemical behavior of th <br />is <br />determined by the <br />g <br />particular ionizable a resin <br />resin. The followinc is a <br />used by the Facililist of five resin attached to the ' <br />ty for metals along with the that may be <br />characteristics of each. portant <br />1• Strong Acid Cation - The i' <br />resin <br />the pH of the solution, <br />mportant characteristics of this <br />type are: The exchan e <br />g capacity is not affected by <br />it is leasthi <br />it is the most durable and itsthe selectivitY is enslow xPslow resin, <br />may pick up hardness in the water. so it <br />2• Weak Acid Cation <br />exchange capacity <br />Important characteristics are: The ' <br />is reduced aL: a solution pH below <br />will tend not to pick up water hardness because 5, it <br />selectivity for heavy metal is higher and i the <br />expensive resin than the strong acid t is a more <br />b <br />of reagents are needed to reverse the reactionlanr amount <br />regenerate the resin. d <br />3 • Stron q Base Anion - ' <br />exchange capacity islunaffectedhbyant asolution Pcteristics are; The <br />generally more expensive than the cation resins, litlha <br />shorter functional life span than cation resins a <br />resin can be fouled b s a <br />Y organics in the solution. and the <br />4• Weak Base Anion <br />Important characteristics are: , <br />exchange capacity is reduced above a The <br />u <br />the resin cost is the same as the strong base aniof71 <br />less reagent is necessary for resin regeneration n' and <br />the strong base anion resin. than for <br />5• Heavy Metal Chelating Resins <br />are. It has a higher selectivitypforaheavnt y metals haracteristics ' <br />does the weak acid cation resin so it can separate than <br />metals from high levels of water hardness in the heavy <br />solution, reduced amounts of reagent are required fo <br />regeneration, it is the most expensive resin t r <br />removal of heavy metals is effective above a solution pH <br />H <br />of 4. p <br />The ion exchange' resins are housed in a canister which is <br />attached to a drain pipe on the rinse tank <br />rinse solution flows through the canister, (see Figure 2). The <br />,Allowing the exiting water to flow to �the <br />metal is removed <br />thesewer <br />exchange capacity of the canister (containing the When the <br />reached, it is replaced by a fresh one, wins) is <br />are transported to the FacilitySaturated canisters <br />is accomplished by flushing the resins gwith aaeco Regeneration <br />or base solution, depending on the resin t concentrated effec- <br />tively acid <br />reverses the exchange reaction. Ype' which <br />A-3 1 <br />1 <br />