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Farmington, NM, United States

Paul D.H.,David H. Paul Inc.
AWWA/AMTA Membrane Technology Conference and Exposition 2012 | Year: 2012

This paper documents the results of a 2,000 hour nanofiltration (NF) pilot study on very challenging North Carolina well water. The challenges were: • Very high iron, up to over 8 mg/L in some wells • Very high silica, up to over 70 mg/L in some wells • A combination of at least two wells is always required to be in operation at all times resulting in both very high iron and very high silica feed water • Silica and iron precipitation in the last elements occurred even at silica concentrations below the published maximum limit for the scale inhibitor used • Experimentation was required using different recovery rates and different scale inhibitors to control silica scaling. © 2012 American Water Works Association. Source

Decker R.,David H. Paul Inc.
Ultrapure Water | Year: 2010

DI is the removal of ions from a water stream. In high-purity water applications, the IX technology exchanges undesirable feedwater ions for hydrogen ions, and hydroxide ions to create ptue water. The EDR technology uses an applied electrical potential to "pull" ions out of a feedwater stream. The electrodeionization technology combines the ion exchange and electrodialysis technologies. Source

Decker R.,David H. Paul Inc.
Ultrapure Water | Year: 2010

A plate-and-frame EDI module comprises cell pairs stacked with an anode and cathode at opposite ends. ADC electrical potential applied across the stack causes cations and anions to migrate towards their respective electrodes. The membrane sheets are made of the same materials as conventional ion-exchange resin beads, and are mixed with a binder to hold them in sheet form. Feedwater anions are attracted to the anode and pass through the anion-exchange resin sheets. A unique phenomenon that occurs during EDI is water splitting. The more conductive the materials in the stack are the easier it is to pass the required current with the voltage available. The ion-exchange materials are many times more conductive than the water to be treated. The biggest source of resistance in a stack is typically the C-compartment because or due to the lack of resin beads. Source

Turner E.,David H. Paul Inc.
Ultrapure Water | Year: 2010

An RO unit's operational data that is already being taken should be inputted into a trending program on a daily basis, and the trends analyzed on a weekly basis to catch problems at an early stage as possible before irreversible fouling/scaling can occur. The three trends to be graphed are NPF, DP, and % SR, or % SP. IfNPF decreases by 10% to 15%, or if DP increases by 15% to 25%, whichever comes first, the RO unit must be chemically cleaned. When trending is implemented at a plant, it generally results in smoother operation, less down time, and cost reduction of the overall operation of the water plant, which can save the company money. Source

Paul D.,David H. Paul Inc.
Ultrapure Water | Year: 2010

Compendial waters are made from PW or WFI. There are conductivity, TOC, and bacterial count limits for PW and WFI. There is also an endotoxin limit for WFI. There are generally several treatment steps using different water treatment technologies required to process a drinking-water-quality feedwater to PW and WFI. Each plant will have a unique process. Source

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