Wastewater Treatment

ION EXCHANGE

The DMP CES Series Decationizer is a sub-system for treating wastewater. The system consists of vertical columns of ion exchange resin through which the prepared wastewater is pumped.

The sole function of the Decationizer is to extract from water the trace metals controlled by environmental guidelines. The CES Series Decationizer can be designed to extract metals commonly used in metal finishing such as copper and nickel.

What is Ion Exchange?

Ion exchange is an adsorption process in which charged molecules, called ions, in a solution are exchanged for other ions on the surface of an adsorbant or resin.

Ion exchange only removes compounds that ionize. It is also a concentration process. The phenomenon of ion exchange occurs in special synthetic resins and in many natural solids. 

How does the process work?

The operation of any ion exchange system involves four steps:

Backwash
This step is carried out with a new installation and after each "run." Water is introduced through the bottom of the ion exchange column at a rate sufficient to expand the resin bed by 50 to 75 percent. The primary purpose of the backwash is to remove any silt, dirt, iron, or other insoluble matter that may have accumulated during the exchange operation. Also, any clumps of resin formed because of tight packing are dispersed and the resin beads are reoriented. 

Regeneration
This step follows backwash and is the displacement of the ions held on the resin sites. These ions were removed from the process feed water during the service cycle.

Rinse
This step follows regeneration. The purpose is to remove excess regenerant prior to putting the unit into service.

Service
This is the operational mode of the system and follows rinsing. The process water containing the dissolved metal or metals is passed through the ion exchanger to remove them. The process continues until the resin has adsorbed metals to its capacity. In most industrial applications, an acceptable or predetermined level of cations or metals in the effluent is set. When this level is reached, "break-through" has occurred. The unit is then taken off-line and is backwashed, regenerated and rinsed before being put back into service.

DMP's CES Series Decationizer consists of four parts:

Cation Exchange System - single or dual skid-mounted pressure vessels with sufficient volume to allow for 100 percent expansion of resin during backwash.

Pumps - the DMP pump system consists of a centrifugal pump of appropriate capacity and pressure for the required flow and appropriate material of construction for the application.

Regeneration Module - one DMP regeneration module with leakproof centrifugal pumps and metering valves.

Solid-State Control Center - one DMP CES Controller which coordinates all pumps and flows necessary for processing the chelated copper waste.

DMP's CES Series Decationizer is available as an automatic, semi-automatic or manual unit.