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Posts Tagged ‘sodium’

Theoretical Gypsum Requirement (TGR) Models

Friday, July 6th, 2012

By John Ashworth,  ALS Environmental – Canada

ALS Environmental Lab TestingGypsum is often applied as an amendment to soils that exhibit a high sodium adsorption ratio (SAR).  The addition of gypsum can reduce a soil’s clay plasticity, thus improving drainage and ease of cultivation. Estimating the correct amount of gypsum required to remediate a particular site is an inexact science requiring experience and consideration of specific site history and conditions, but models described in the literature can produce theoretical estimates to provide guidance.  As a service to our clients, ALS now offers two theoretical calculations for gypsum requirement that are suited to two common categories of salt-impacted soil on the Canadian prairies.

Deionized vs. Distilled Water

Monday, July 12th, 2010

By Gregory Salata, Ph.D., Kelso, WA

Deionized vs. Distilled Water

Many sampling programs include collection and analysis of an equipment blank to ensure there is no contribution of contaminants from the sampling equipment and associated process. To establish that sample collection procedures are contaminant free, an equipment blank is often collected. Equipment blanks are collected by passing water through the sample collection apparatus or utensil and collecting the water into the appropriate containers. To ensure that the water itself is contaminant free, the laboratory will supply the field crew with deionized (DI) water.

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