Using performance prediction software to forecast ion exchange resin performance. Simulation technology with its ion exchange (IX) application can provide additional advantages validated by number of simulated pilot plant studies covering hundreds of cycles of exhaustion and regeneration. The advanced simulation technology is known to combine mass action and kinetic relationships to simulate exhaustion and calculating profile for each ion in each portion of the water and the resin bed as the water. The behavior of all contaminants can be modeled by simulation technology by comparing the peak and average leakage levels with Maximum Contaminants List (MCL) guidelines. The initially performed simulations exhibited the effluent profiles for the virgin cycle of operation by employing a nitrate selective resin with an aim to prevent the chromatographic dumping of nitrates by sulfates. Simulation technology can also replace physical pilot plant studies providing data in minutes that can further stimulate concurrent, countercurrent and homogenized bed regeneration techniques for the desired number of cycles.

Predicting resin life and the effects of chlorine and chloramine disinfection

Techniques for removing hexavalent chromium. Presented at 2002 WQA.

Cleaning Biologically Fouled Resins

Evaluation of cleaning efficacy of oil fouled cation softening resins. Presented at IWC in 1994.

Application advice for the use of anion resins to remove naturally occurring organic matter (NOM). Written by MG for Water Technology Magazine in 1999.

Fundamentals of ion exchange technology

Ultrapure water production by the use of mixed bed ion exchange resin. Factors that influence ultimate quality are presented and discussed.

When to replace anion exchange resin due to oxidation, fouling, or other reasons.

How to selectively remove heavy metals from water.

How to interpret and understand the results of an ion exchange resin analysis. When is it time to replace or clean resin?

Removal of lead from water.

How to achieve low total organic carbon (TOC) levels in ultrapure water using mixed bed DI resins.

The removal of molybdenum from cooling loops using ion exchange resin. Written by Andrew Bishop, formerly of ResinTech.

A comparison between strong base anion resins for nitrate removal, both general resins and selective resins.

Removal of NOM using a specialty anion resin.

How to save substantial amounts of rinse water in the regeneration plant.

Soaking a freshly regenerated mixed bed tank overnight in DI water before use can help achieve a higher purity effluent when put into service.

The benefits of using potassium chloride versus sodium chloride as a brine regenerant.

How to predict the field operating capacity of strong base anion resins based on their current chemical condition as reported by the analytical laboratory.

The use of strong base anion resins operated in the chloride form for removal of natural organic material.

A study of the use of anion exchange resins for the removal of natural organics from water.

The use of specialty hybrid resins for the selective removal of silica from nuclear process water and radwaste.

The effects of temperature on ion exchange resin operations.

The importance of deionized (DI) water for the aquarium market.

What conditions are best for storing semiconductor ultrapure resins before use to maintain integrity?

How the power generation industry uses portable exchange DI service to provide demineralized makeup water. Economics are discussed. Regional portable exchange deionization (PEDI) service companies provide external regeneration of exchange tanks or user-owned vessels. This service covers flows to several hundred GPM and effluent quality up to 18 megohm, low TOC polishing mixed beds. Power generation plants are finding advantages utilizing these service companies to regenerate their mixed bed DI polishers off- site, especially when RO units and/or other bulk ion removal systems are involved. Technical, economic and environmental issues will be discussed as well as the structure of a regional PEDI company.

Considerations for the use of portable exchange DI service for providing demineralized water.

How does the concentration of background ions affect the removal of contaminants from water using ion exchange? What changes can be expected in treated water?

The removal of uranium from water supplies using chloride form anion resins.

In the water treatment market, at some point, you are likely to have a client ask to have their water tested. The big question is: "Tested for what?" Depending on the client, the answer could be drastically different.

Solutions for removing arsenic from water.

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How to protect ion exchange resin from oxidation, fouling and loss during use.

Frank Desilva responds to Water Technology readers' questions.

The use of ion exchange resins for removal of trace contaminants such as uranium, radium, perchlorate, chromate, and arsenic.

Strong base anion resins (SBA), operated in the chloride form, can remove many contaminants from drinking water. These contaminants include arsenic V (also known as arsenate), nitrate, chromate, fluoride and uranium. The two types of strong base anion exchange resins commonly used today are Type 1 and Type 2 strongly basic anion exchange resins. Both resins can be used to remove the contaminants listed above.

How to remove arsenic from water using brine regenerable anion resin.

Using two IX units for meeting drinking water limits.

NOTE: the author of this article is Kaitlyn Clark The ability to remove trace contaminants by ion exchange resins is influenced by the relationships between inlet water TDS and contaminant concentration .

The selective removal of perchlorate from groundwater using ion exchange.

How to keep suspended solids from entering the ion exchange bed. How to properly backwash and clean a bed that may have become impacted by suspended solids accumulation.

Removing radium from drinking water sources using conventional softening resins and also selective resin.

The fundamentals of regenerating softeners and two bed deionizers

Resin regeneration fundamentals.

Peter Meyers responds to WC&P readers' questions.

How to disinfect a bed of ion exchange resin.

A series of experiments were conducted to determine the uptake rates of tannic acid by styrenic strong-base Type-1, anion-exchange resins with a wide variety of moisture contents. Our goal was to determine the relationships between gel-phase moisture, total capacity, and physical structure for tannic acid uptake capacity and leakage. The results show a strong correlation between the increasing moisture content and improved exchange of chlorides for tannin. It was found that initial performance and performance stability as defined by the height of the transfer unit (HTU), for tannin/chloride exchange was dependent on the moisture content of the gel phase of the resin. The resins tested had gel-phase moisture contents that ranged from 40.7% to 80.8% (chloride form).

How to choose the correct softening resin for your application. Among the choices are 8% crosslinked, 10% crosslinked, gel, macroporous, fine mesh, coarse mesh, uniform particle size, and solventless.

The history of PFAS, measurement techniques and removal methods.

Water Treatment Plant Design, Fifth Edition By American Society of Civil Engineers

Ion Exchange Part 1: Keys to Successful IX Resin Storage

Silica is poorly ionized at neutral pH and has limited solubility. Membrane and precipitation processes can be quite effective at elevated pH but are either ineffective or less than wonderful at neutral pH. Demineralizers, with hydroxide-form anion resin, remain one of the best methods for removing silica, especially when TDS removal is also required.

Silica has always confounded water treatment dealers in how to handle it and greatly reduce the contaminant. As we discover more information about silica due to further studies, though, some technologies have come to the fore. A good place to begin is to examine the chemistry of silica and how it pertains to various approaches available to dealers.

Dealkalization is the process of removing anions such as bicarbonates, carbonates, sulfates, and nitrates with a chloride anion exchange.

An ion exchange water treatment system is a specialized technology used in wastewater treatment to remove dissolved ions and contaminants from water.

Ion Exchange Part 2: Tips on Moving Ion Exchange Resins from Place to Place

Ion Exchange Part 3: Tips for Loading and Unloading IX Resins

What Are the Best (and Cheapest) Ways to Dispose of Ion Exchange Resins? By Philip Overton

Water Treatment Plant Design, Fourth Edition By American Society of Civil Engineers

Chelating resins are gaining acceptance as the best available technology for the removal of transition and heavy metal cations from ground water and from plating rinse waters. These specialty ion exchange resins are capable of removing metals selectively in the presence of other ions such as calcium, magnesium and sodium. This paper describes the various types of chelating resins that are commercially available, discusses the conditions under which they will and will not work, and explores the input require-ments necessary to optimize a system design.

A guide to understanding the basic principles of ion exchange for the metal finishing industry.

In Part 1, we discussed aspects of ion selectivity as they relate to water softening, including selectivity coefficients, apparent selectivity and selectivity reversal. In Part 2, we take up the mathematical relationships of concentration, valence and capacity, which underlie the theory of water softening.

A recent spate of regulations in a number of states has served notice to resin suppliers th

Though its popularity as a water treatment alternative is increasing, activated carbon can have a substantial effect on pH. These “spikes” in pH become even more pronounced in various high-purity applications. Pre-wetted carbons, however, answer many of those concerns in a sufficient manner. The advantages of pre-wetted pH adjusted acid-washed carbons are discussed.

Countercurrent regeneration is a method that has tried unsuccessfully to get into the mainstream of the water softening industry. Despite various application strategies, it’s often dismissed as too complex and with little value in brine savings. Time will tell if other issues such as salt and the environment make the technique practical.

Recently, a handful of portable exchange deionization (PEDI) operators in California were cited fo

The concept of water softening has been in use longer than many of us may have been led to believe. Here, the author gives a brief historical lesson as well as a look into the future on where he sees the industry headed.

Silica has always confounded water treatment dealers in how to handle it and greatly reduce the contaminant. As we discover more information about silica due to further studies, though, some technologies have come to the fore. A good place to begin is to examine the chemistry of silica and how it pertains to various approaches available to dealers.

Scientists use deionized water in a variety of areas from glassware washing to DNA synthesis. To provide the proper deionization system, it’s important to understand the specific needs and requirements of laboratory grade water. Laboratory water systems come in standard configurations with a variety of available options.

As a general class, the arsenic adsorbents are all based on similar adsorbent chemistry. An insoluble metal oxide/hydroxide is the adsorbent, which is contained in some type of granular substrate that is porous enough to expose the adsorption sites to the water, yet robust enough to maintain its shape under the conditions of use. Arsenic in the form of arsenate, an anion, is adsorbed by co-precipitation onto the metal oxide, while arsenate (trivalent arsenic) is attracted by chelating forces. Precipitated arsenate, in most cases, is tightly bound to the oxide and does not come back off under any normal conditions found in potable water. All of the arsenic adsorbents promise extremely long throughputs by targeting the arsenic species, while ignoring common ions, such as sulfate, chloride, sodium, calcium, etc.

How to balance a partial water analysis to make up for missing parameters.

Factors affecting the efficiency and performance of brine regenerated water softeners

What compounds can leach from softener resins when exposed to chlorine or other oxidants?

The ResinTech story.

A little of this and a little of that may work in spicing a pot of stew, but when it comes to ion exchange float, you’d better know all the considerations in choosing new resin to add. More often than not, it’s a like-to-like equation. Here, such issues are discussed in detail for the dealer, who may also do commercial/light industrial work.

Methods of producing ultrapure POU water for laboratory use.

There are many uses a water conditioner can be put to beyond simply softening water. Some require more care and expertise because of potential health risks if not handled properly. Following is an overview on this concept.

Discussion of various methods of fluoride removal from water sources.

New rules released late last year from the Food and Drug Administration (FDA) on water purification for ki

The removal of insoluble ferric iron by water softeners can be problematic. Softening resins filter to approximately two microns in size but ferric iron particles are often smaller than one micron.Depending on particle size, flowrate and resin size and uniformity, removal can be as little as 10 percent or as much as 90 percent with 25- to 75-percent removal more typical. Fine-mesh resins do better than larger resins.

Water softening is an inherently efficient process. This is true for the service cycle, where sodium ions on the resin are exchanged for hardness ions in the water. And, unlike most chemical reactions, it’s true during the reverse exchange, or regeneration, where sodium ions in the brine are swapped for hardness ions on the resin. Few chemical processes are efficient in both directions. The reason for water softening efficiency is a phenomenon called selectivity reversal that’s caused by changes in the solution concentration when the ion exchange reaction involves ions of unequal valence. The principal of selectivity reversal underlies all ion exchange theory and is the science behind the art of softening water.

Discusses the selection and use of anion resin for removal of contaminants from water and the influence of sulfate levels.

How to store, load and dispose of ion exchange resin.

Cation exchange resin is available in amber or dark colored beads. Which color is best for your application?

Article describing the use of SIR-700-HP for removal of hexavalent chromate from contaminated groundwater at a Superfund site in Vancouver, WA.

Selection of Ion exchange resins for sugar decolorization as per the color of sugar syrup