Documentation sur le produit

Several installations in the southwest are illustrated as examples of nitrate removal systems using ion exchange resin.

Cities throughout the Southwest have found that next-generation ion-exchange technologies provide a reliable, economical, ready-made way to leverage local groundwater resources without the expense of a hard-piped treatment facility or the problems of dealing with waste management.

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

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.

How to avoid or accommodate pH variances in granular activated carbon.

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

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

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.

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.

NOTE: the author of this article is Kaitlyn Clark

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).

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

Recycling water using DI at an ammunition plant.

Discussion of various methods of fluoride removal from water sources.

When approaching a rebed of an ion exchange unit it is important to determine if it is the best course of action, how you will remove the resin from the vessel and your plan to load the new resin. The need to rebed an ion exchange unit can be the result of problems with effluent quality, operating capacity and/or run lengths. These problems arise from changes in operating procedures, incoming water composition, resin loss or resin age.

Frank Desilva talks about the new ResinTech manufacturing facility in New Jersey, how he makes ion exchange a more interesting topic for conversations and sales presentations, and one of the positives he sees coming out of the pandemic.

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.

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.

Recently, a handful of portable exchange deionization (PEDI) operators in California were cited for excessive discharges of copper. How and why could this happen when the general use of the portable exchange tanks was treatment of potable water, not copper-containing wastewaters? Here’s an explanation and some suggestions.

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?

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.

This is a review of how chloride form anion resin impacts the pH of water and why.