A patented technique to pre-treat activated carbon with a weakly adsorbed organic acid for pH sensitive applications involving treatment of potable drinking water, industrial process water, and groundwater remediation.
A patented technique to pre-treat activated carbon with a weakly adsorbed organic acid for pH sensitive applications involving treatment of potable drinking water, industrial process water, and groundwater remediation.
A patented technique to pre-treat activated carbon with a weakly adsorbed organic acid for pH sensitive applications involving treatment of potable drinking water, industrial process water, and groundwater remediation.
A common problem associated with the start-up of fresh beds of activated carbon in water treatment applications is an inadvertent pH rise. No definitive theory as to why this pH spike occurs has been proven.
The exact intensity and duration of the pH increase is greatly dependent upon the water chemistry in any given application, but typically ranges from one to three pH points and persists for several thousand bed volumes of water.
This pH change can cause substantial compliance issues for some facilities. Evoqua Water Technologies has developed our NoRise process, a patented (US Patent Nos. 6,946,077 and 7,300,586) technique to pre-treat activated carbon with a weakly adsorbed organic acid. As a result, the pH rise is mitigated without affecting the long-term performance of the carbon.
NoRise-treated carbons have been rigorously tested on a myriad of influent water types, including groundwater, surface water, and process waters. In each case, the pH rise was successfully reduced with tighter pH control than standard acid washed carbons.
The NoRise process can be applied to both virgin and reactivated activated carbons in a variety of mesh sizes.
No definitive theory as to why this pH spike occurs has been proven. Potential causes of the original pH increase in untreated carbons include leaching of alkaline constituents from the carbon’s ash and ion exchange interactions with surface groups on the carbon which generate hydroxide (OH-) ions that raise the water’s pH.
For information on applying our NoRise process to our base carbons, please contact your Evoqua Water Technologies Technical Sales RepresentativeAll Westates® brand activated carbons are extensively quality checked at our State of California certified environmental and carbon testing laboratory located in Los Angeles, CA. Our laboratory is fully equipped to provide complete quality control analyses using ASTM standard test methods in order to assure the consistent quality of all Westates brand carbons.
*Note that the pH rise phenomenon is a water chemistry issue, not normally related to carbon quality or constituents. Prior to applying NoRise we recommend speaking with a technical sales representative.
A patented (US Patent Nos. 6,946,077 and 7,300,586) technique to pre-treat activated carbon with a weakly adsorbed organic acid. As a result, the pH rise is mitigated without affecting the long-term performance of the carbon.
