Water solids determination

TDS total dissolved solids determined by evaporating the water and weighing the residue. Units are mg/l. 

For wastewater samples, a number of additional solid determinations are typically performed, including total dissolved solids, volatile solids, and settleable solids. Total dissolved solids are the total solids minus the suspended solids and are determined in a manner similar to total solids, but after filtering out the suspended solids. Thus, a volume of the filtrate is measured into the evaporating dish and the water evaporated in a drying oven. 

The data for the reactions of potassium cyanide with benzyl halides at 85 C and 25 C are summarized in Tables I-III and graphical representations of these data are shown in Figures 1-3. The reactions carried out at 85 C were followed to 70% completion, while those at 25 C were followed to 50% completion. In general, excellent first-order kinetic plots were obtained. Each point on the graphs represents an average of at least three kinetic determinations. It is interesting to note that in the absence of added water (solid-liquid phase transfer catalysis), the rates of benzyl halide disappearance were more accurately described by zero-order kinetics. 

The errors in this approximation are usually tolerable if the normal solids concentration is more than 10 times the actual atomized low solids water solids concentration. This obviously necessitates a determination of the solids concentration in the atomized water at or from the atomizer. 

In the coulometric method, standardization is not necessary, since the current consumed can be measured absolutely. However, a standard with known water content should be checked periodically to ensure that the system is functioning properly. In this case, a certified water standard is generally used, and the amount of water is determined and compared with the amount that is certified to be present. Some coulometric titrators are equipped with an oven for liberating the moisture from samples that are either insoluble in methanol or that react with I2, methanol, or one of the other reagents. Solid standards (e.g., potassium citrate monohydrate) are available for checking the oven, and this check is performed after the coulometer function has been verified. 

The appropriate amounts of sample and water are determined from the desired amount of solids and the Brix measurement. For 100 g solids from an 18°Brix press liquor, the homogenate would consist of 100 g solids X (1/0.18) - 556 g press liquor and 2444 g water. 

A subtle aspect of stability analysis of freeze-dried products in vials with rubber stoppers is the tendency for water vapor to be transferred from the stopper to the solid during storage. Representative data for residual moisture as a function of time at different temperatures are shown in Figure 11. As expected, the residual moisture level increases more rapidly at higher temperature, but the plateau level is independent of temperature as equilibrium is established between the freeze-dried solid and the stopper. The extent to which this is observed depends on several factors. First, the nature of the rubber stopper formulation affects the diffusivity of water in the rubber. Second, the processing of the stopper can affect the level of residual moisture present. It is not uncommon for extended drying of the stopper to be necessary to minimize residual moisture. Finally, the mass of the freeze-dried solid determines the extent to which the percent residual moisture is affected by water vapor transfer from the stopper, where large cakes may be relatively unaffected by the small amount of water vapor that is... 

Schuette, S.A, R.G. Smith, L.R. Holden, and J.A. Graham (1990). Solid-phase extraction of herbicides from well water for determination by gas chromatography-mass spectrometry. Anal. Chim. Acta, 236 141-144. 

DIN 38409-H22.2001. DIN 38409 H22. Water Quality—Determination of Adsorbable Organically Bound Halogens in Highly Saline Waters After Solid Phase Extraction (SPE-AOX). Berlin Beuth-Verlag. 

Terpolymer Resins. DBPF was dissolved in a mixture of styrene, acrylonitrile, and mercaptan (Table I). About one-tenth of this solution was added to a solution of sodium alkylbenzene sulfonate emulsifier (Nacconal NRSF, 2 parts) in deionized water (180 parts) at 60°C. Potassium persulfate (0.3 part) was added, followed by the remaining monomer mixture at a rate consistent with temperature control (60°C.) Gentle agitation and a nitrogen atmosphere were maintained throughout the polymerization. The latex was maintained at 60 °C. until a solids determination indicated no further conversion (6—8 hours total polymerization time). 

Total Solids Determine the water content of an accurately weighed sample as directed under Water Determination, Appendix IIB. Calculate the percent Total Solids by the formula... 

For soil/sediment samples the results of these analyses are reported based on the wet weight of the sample. However, use of the SDS apparatus allows the water content of a sample to be determined from the same aliquot of sample that is also extracted for analysis. The amount of water evolved from the sample during extraction is used to approximate the percent solids content of the sample. The percent solids data may be employed by the data user to approximate the dry weight concentrations. The percent solids determination does not apply to the extraction of particulates from the filtration of water samples or to the extraction of fly ash samples which are treated with an HC1 solution prior to extraction. 

Partition between compartments within the aqueous environment is typically described through the octanol water partition coefficient, Aiow, or the organic carbon-water partitioning coefficient, (see Chapter 5). This approach assumes that partitioning from water into fish or suspended solids within the water is determined by the availability of organic matter whose properties as a solvent can be described by a parallel with octanol for which partitioning data are widely available... 

Figure 2-15. Relation between the reciprocal of leaf water potential determined with a pressure chamber (Fig. 2-10) and the volume of xylem sap extruded as the air pressure in the chamber is progressively increased. The solid line indicates a typical range for data points for material initially at full turgor (TJ, = 0). The reciprocal of the internal osmotic pressure (1/n1) including the value at full turgor (1 /nj,), the internal hydrostatic pressure (P1), the point of incipient plasmolysis and turgor loss, and the volume of symplastic water (VSympiasm) can all be determined from such a P-V curve.

Characterization of the activated carbon by adsorption nearly saturated water with benzene and activated carbon were introduced into a batch reactor with a 0.06 and 0.14 ratio of solid/liquid phases. In each experiment, the evolution ofthe concentration of benzene in water was determined spectrophotometrically and by potassium permanganate titration. Tables 3.22 and 3.23 as well as Figs. 3.82-3.84 show... 

Oil and Water Content with Solids. Many methods determine the relative amounts of water and oil in emulsions. Because many emulsions of interest to the oil industry also contain solids, determination of the solids content is also important (22, 23). The Institute of Petroleum (IP), the American Petroleum Institute (API), and the American Society for Testing and Materials (ASTM) have developed standard methods for these determinations, as have most organizations or laboratories where these determinations are routinely performed (24-28). These methods are all some modification of the Dean-Stark procedure, in which the sample is placed in a porous thimble and refluxed with a suitable organic solvent. 

Size Distribution Using Electrical Properties. As mentioned earlier, for water content determinations, techniques that depend upon differences in electrical properties do not distinguish between water and solids. This property limits their applicability to systems in which solids are negligible or the process stream is so well defined that the differences in signal can be attributed to differences in size distribution and not to total water and solids (50, 51). Clearly these measurements require extensive calibration and are not generally applicable to oil-field emulsions. 

Water was determined in several matrices in 1968. Solid samples were analyzed for hydrous and anhydrous forms of strychnine sulfate, sodium tartrate, and ammonium oxalate mixed with KCI and compressed into disks containing 100 mg KCI and 25 mg drug. 

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