This method is included in NEMI for informational purposes as it is approved by EPA for regulatory use. Detailed information on this method is not currently. eropoly acid. This is reduced to silicomolybdenum blue that is determined pho- tometrically. The method is analogous to APHA SiO2 D+E, ASTM D, . Find the most up-to-date version of ASTM D at Engineering
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The collecting apparatus and storage containers for the reagent water must be polyethylene or other suitable plastic.
For seawater or brines, this test method is applicable only if matched matrix standards or standard addition techniques are employed. 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. Due to the complexity of silica chemistry, the form of silica measured is de? After dissolving, d8599 the solution to mL of a solution containing 30 g of sodium hydrogen sul?
The type and composition of the silica-containing minerals in contact with the water and the pH of the water are the primary factors controlling both the solubility and the form of silica in the resulting solution. Check the concentration of this solution gravimetrically.
ASTM D859 – 16
It is applicable to most waters, but some waters may require filtration and dilution to remove interferences from color and turbidity. For standards in the 0. Originally approved in It may be monomeric or polymeric. Historical Version s – view previous versions of standard Translated Version s: Summary of Test Method 4. Individual reprints single or multiple d8859 of this standard may be obtained by contacting ASTM at the above address or at phone wstm, faxor service astm.
It is particularly applicable to treated industrial waters.
Standard Test Method for Silica in Water
No other units of measurement are included in this standard. The MS should be prepared in accordance with Guide D When working with low concentrations of silica, a batch of ammonium molybdate known to produce reasonable blanks, linearity, and reproducibility should be set aside for this purpose. Prepare a blank using a Measurements may be made at nm with a spectrophotometer, or to nm with a? Note 1—For many natural waters, a measurement of asrm silica by atsm test method provides a close approximation of total silica, and, in practice, the colorimetric method is frequently substituted for other more time-consuming techniques.
ASTM D – 16 Standard Test Method for Silica in Water
It is applicable to most waters, but some waters may require filtration and dilution to remove interferences from color asrm turbidity. A superscript epsilon e indicates an editorial change since the last revision or reapproval.
Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Those forms of silica that are molybdate-reactive include dissolved simple silicates, monomeric silica and silicic acid, and an undetermined fraction asrm polymeric silica. Type II water was speci?
ASTM D 水中硅测定的标准方法_百度文库
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part f859 the standard. High blanks, nonlinear calibration curves, and poor reproducibility have been observed with some batches of this compound.
NOTE 1—For many natural waters, a measurement of molybdatereactive silica by this test method provides a close approximation of total silica, and, in practice, the colorimetric method is frequently substituted xstm other more time-consuming techniques.
Those forms of silica that are molybdate-reactive include dissolved simple silicates, monomeric silica and silicic acid, and an undetermined fraction of polymeric silica.
The mean and standard deviation of the seven values should then be calculated and compared, according to Practice D asym, to the single operator precision and recovery established for this Test Method. For seawater or brines, this test method is d895 only if matched matrix standards or standard addition techniques are employed. The analyte recoveries for the LCS should fall within the control limits of x 6 3S, where x is the IDP amount and S is the standard deviation of the mean recovery adtm from The precision of the duplicate analysis should be compared, according to Practice Dto the nearest tabulated S0 value established from the interlaboratory precision and bias study data for each analyte.
The upper limit for acceptable precision and the range of acceptable recoveries are detailed below: ASTM D95 – Analyte Silica MS Amount ? In contrast, silica may be added as a treatment chemical in some systems, for example, in corrosion control.