Astm d859

Posted by

It is particularly applicable to treated industrial waters. In cooling water systems, silica forms deposits when solubility limits are exceeded. It may be applied to natural waters and wastewaters following filtration or dilution, or both.

Uploader: Digis
Date Added: 2 August 2006
File Size: 21.50 Mb
Operating Systems: Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X
Downloads: 24496
Price: Free* [*Free Regsitration Required]





Silicon is the most abundant element in igneous rocks and is the characteristic element of all important rocks except the carbonates. Silica may exist in suspended particles, as a colloid, or in solution. It may be applied to natural waters and wastewaters following filtration or dilution, or both.

For seawater or brines, this test method is applicable only if matched matrix standards or standard addition techniques are employed.

Referenced Documents purchase separately The documents listed below are referenced within the subject standard but aetm not provided as part of the standard. Due to the complexity of silica chemistry, the form of silica measured is defined by the analytical method as molybdate-reactive silica.

ASTM D - 10 Standard Test Method for Silica in Water

Historical Version s - view previous versions of standard. It is particularly applicable to treated industrial waters. For seawater or brines, this test method is applicable only if matched matrix standards or standard addition techniques are employed.

Refer to Appendix X1 for historical information.

Active view current version of standard Translated Standard: Those forms of silica that are molybdate-reactive include dissolved simple silicates, monomeric silica and silicic acid, and an undetermined fraction of polymeric silica. No other units of measurement are included in this standard.

For many natural waters, a measurement of molybdate-reactive silica by this test method provides a close approximation of total silica, and, in practice, the colorimetric method is frequently substituted for other more time-consuming techniques.

It is the skeletal material of diatoms but is not known to play a significant role in the structure of processes of higher life forms. This is acceptable when, as frequently occurs, the molybdate-reactive silica is in the milligram per litre concentration range while the nonmolybdate-reactive silica, if present at all, is in the microgram per litre concentration range. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

It may be monomeric or polymeric. No other units of measurement are included in this standard. Due to the complexity of silica chemistry, the form of silica measured is defined by the analytical method as molybdate-reactive silica. Silica removal is commonly accomplished by ion exchange, distillation, reverse osmosis, or by precipitation, usually with magnesium compounds in a hot or cold lime softening process.

Historical Version s - view previous versions of standard Translated Version s: Under certain conditions, silica forms troublesome silica and silicate scales, particularly on high-pressure steam turbine blades. In cooling water systems, silica forms deposits when solubility limits are exceeded.

It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. It is applicable to d895 waters, but some waters may require filtration and dilution to sstm interferences from color and turbidity.

Active view current version of standard. It may be applied to natural waters and wastewaters following filtration or dilution, or both.

This is acceptable when, aetm frequently occurs, the molybdate-reactive silica is in the milligram per litre concentration range while the nonmolybdate-reactive silica, if present at all, is in the microgram per litre concentration range. It is found as the oxide in crystalline forms, as in quartz; combined with other oxides and metals in a variety of silicates; and in amorphous forms.

ASTM D859 - 16

In solution it can exist as silicic acid or silicate ion, depending upon pH. It is particularly applicable to treated industrial waters. Refer to Appendix X1 for historical information. Link to Active This link will always route to the current Active version of the adtm.

It is applicable to most waters, but some waters may require filtration and dilution to remove interferences from color and turbidity.

In contrast, silica may be added as a treatment chemical in some systems, for example, in corrosion control. Link to Active This link will always route to the current Active version of the standard.

1 comments

Leave a Reply

Your email address will not be published. Required fields are marked *