ION EXCHANGE WATER RECYCLE

The make-up and recycling of process waters are important to the success of many manufacturing facilities. With ion exchange media, these goals are easily achieved.

In many areas, incoming waters for processes are hard (calcium & magnesium) and filled with minerals that are harmful for manufacturing that will be used in the process. Ion exchange resins can be utilized to soften and/or deionize the water. It is important to understand that poor incoming city or well water can lead to stained or pitted parts. In order to ensure a consistent water quality, pre-treating of the make-up water is important.

The never-ending need of reducing water consumption and discharge can be alleviated with the recycling of process waters. Through a dual bed (cation & anion) ion exchange system, economically these goals can be achieved. There are many positives in recycling industrial process waters. The savings on water usage and discharge permitting are the two most significant. Another benefit many companies are not aware of is a consistent temperature. As water enters a plant in midwinter months, cold temperatures can cause inconsistent rinsing of parts. The general need to conserve on water consumption and discharge is an aspect that should never be overlooked.

A standard dual bed ion exchange unit consists of a strong acid cation resin that exchanges hydrogen for positively charged cations present. The second step is a week or strong basic anion resin that exchanges hydroxide for negatively charged anions present in the water stream. The hydrogen (H+) from the cation exchanger and hydroxide (OH-) from the anion exchanger create the HOH or deionized water to be reused in the process.

There are certain processes that generate an abundance of either a cation or an anion. If this occurs, a more selective weak acid cation can be used to exchange the multi-divalent heavy metals that are in abundance. This “pre-treating” of the heavy metals will assist in the exchanging of the mono-valent cations. A weak basic anion before the strong basic anion can be implemented to assist in pre-treating for hexavalent chrome.

The cation ion exchange resin is regenerated with an acid to exchange the hydrogen back onto the cation resin beads. The anion is regenerated with sodium hydroxide to exchange the hydroxide back onto the anion resin beads. The cost and wastewater associated with the regeneration of the ion exchange media is minimal. Using a 20 to 30 GPM standard dual bed cation/anion unit as an example, the cost per day (based on seven days) to regenerate is approximately $60.00 and the water volume generated from the regeneration is approximately 1500 gallons.

L & T Technologies, Inc. offers a wide array of standard or custom tailored deionization units. Let L & T Technologies, Inc. be your avenue to recycling and recovering your aqueous solutions.

Through LT Technologies’ 3-tier of success (consultation, capital equipment manufacturing and high-end services) we can develop a treatment strategy to meet the upcoming need for more stringent effluent discharge limits.

 Ion Exchange Recycle Systems