An ion exchange system consists of a tank containing small beads of synthetic resin. The beads are treated to selectively adsorb either cations(positive) or anions(negative) and exchange certain ions based on their relative activity compared to the resin. This process of ion exchange will continue until all available exchange sites are filled,at which point the resin is exhausted and must be regenerated by suitable chemicals.
- Shop-built, modular designs delivered for quick, easy installation and start-up.
- High-efficiency, multi-bed designs to produce waste rates that match available disposal options while minimizing regenerant inputs and waste products, as consumables and waste handling drive the overall cost of contaminant removal in many locations.
- Redundancy and control system capabilities that provide the data system set-point optimization needed to ensure quality goals are continuously met while minimizing operating costs.
- Sensing, data logging, and remote communication capabilities to enable operators to review and attend the unit as needed either from a distance or on site.
The ion exchange water softener is one of the most common tools of water treatment. Its function is to remove scale-forming calcium and magnesium ions from hard water. In many cases soluble iron (ferrous) can also be removed with softeners. A standard water softener has four major components: a resin tank, resin, a brine tank and a valve or controller.
Napier-Reid manufactures a wide range of custom-built softening, dematerializing plants for industrial process water applications, with inherent design to conserve water, and save costs. They are available in different sizes and materials, manually operated or fully automatic and ready to install. Available as standard models or custom built versions for specific needs.
Nitrate levels are coming under stricter control due to health and environmental concerns. Ion exchange technology not only effectively removes nitrate from groundwater, but also generates minimum waste volume resulting in significant savings for total operating costs.
The ion exchange process for the removal of nitrates is both simple and effective. It operates in the same manner as a common water softener and can easily remove well over 90 percent of nitrates. The process uses a strong-base anion exchange resin, which is regenerated with common salt (NaCl) or potassium chloride (KCl). The chloride ion of the salt is utilized by the resin. The sodium ion passes right through the resin bed and does not affect the process.
Depending on the treatment system and the chemistry of the water being treated, ion exchange waste volume typically ranges from 3% to as low as 0.2% compared with 20% – 25% for Reverse Osmosis (RO), making ion exchange technology the preferred choice for groundwater nitrate removal.
Demineralization or Deionization
Demineralization is the process of removing mineral salts from water by using the ion exchange process. With most natural water sources it is possible to use demineralization and produce water of a higher quality than conventional distillation.
Undesirable cations in the water are replaced with hydrogen ions from a strong acid cation (SAC) bed; undesirable anions are replaced with hydroxyls from strong base anion (SBA) bed. The hydrogen ions and hydroxyls recombine producing water molecules, thus, no ions remain in the produced water.
When resin becomes exhausted, it will be regenerated by designated regenerant. For SAC, strong acid, such as sulphuric acid or hydrochloric acid, will be used and hydrogen ions will replace absorbed cations in SAC bed. Caustic soda is regenerant for SBA and hydroxyls will replace absorbed anions in SBA bed. After regenerations, SAC and SBA beds will be put into demineralization process again.
Heavy Metal Removal and Recovery from Wastewater
Heavy metals can be absorbed by living organisms due to their high solubility in aquatic environments. Napier-Reid provides wastewater treatment solutions for industrial facility operators to reduce heavy metals in waste streams to help ensure regulatory compliance. Metals that can be removed include soluble and/or particulate heavy metals, such as lead, copper, chromium, iron, manganese, mercury, nickel, and zinc.
Napier-Reid’s Package Demineralized Water Systems efficiently treat water or wastewater to meets increasingly stringent effluent requirements.
- Removes heavy metals from wastewater over a wide pH range
- Reduces treatment costs
- Helps meet regulatory requirements
- Reduces potential for future remediation
- Improves community health
- Enables wastewater recycling for plant processes