Total sulfate

The anhydrite saturation curve is drawn at constant total sulfate concentration and temperature. 

If a section cut through a small sulfur-burned area of a lemon injured on the tree is examined microscopically, coagulation of protoplasm and cell collapse are apparent. Also, the injured tissue stains abnormally dark with safranin indicating the protoplasm has become more acidic than in normal tissue (18). Sides of the peel of lemons burned by sulfur on the tree were found to be higher in total sulfate than were uninjured sides of the same peel. The high total sulfate content of the peel was subsequently found to be due in part to soluble sulfate, as shown by analyses of the expressed cell solution (18). 

Because of potential glass fiber sulfate artifacts, a separate sampling for total sulfate was made using a polycarbonate filter. 

The determination of total sulfate in nickel-plating solutions using diso-dium-ethylenediaminetetraacetate. Electroplating and metal finishing 6, 41 (1953). 

Total sulfate may be determined in a 50 50 water-methanolic formaldehyde solution by titration with standardized 0.1//lead perchlorate. Endpoint detection is effected using a combination lead ion-selective electrode, and the level of sulfate is typically 13.8 wt % [14]. 

TABLE VI. TOTAL SULFATE CONCENTRATIONS DURING A DUST STORM... 

Gold EW (1981) The quantitative spectrophotometric estimation of total sulfated glycosaminoglycan levels. Biochim Biophys Acta 673 40-415... 

On the basis of mass balance calculations through the first 3 years of acid additions (17), only 33% of the added acid resulted in a decrease in lake alkalinity. A second 33% was neutralized by in-lake (IAG) processes, of which sulfate reduction accounted for slightly more than half and cation production for slightly less than half. Approximately 33% of the total sulfate load (wet and dry deposition, and acid additions) was lost via outflow. Therefore, about half of the added acid remained in the water column two thirds of it was unreacted and one third was neutralized by base cations. 

Mass-balance calculations for the first 3 years of acid additions indicate that the principal IAG processes are sulfate reduction and cation production. Specifically, one-third of the total sulfate input (added acid and deposition) was neutralized by in-lake processes. Increased sulfate reduction consumed slightly more than one-sixth and production of cations neutralized somewhat less than one-sixth of the acid added. Of the remaining sulfate, one-third was lost by outflow, and one-third decreased lake alkalinity. Laboratory determinations suggest that sediment-exchange processes occurring in only the top 2 cm of surficial sediments can account for the observed increase in water-column cations. Acidification of the near-surface sediments (with partial loss of exchangeable cations) will slow recovery because of the need to exchange the sediment-bound H+ and neutralize it by other processes. Reactor-based models that include the primary IAG processes predict that... 

For wet and dry deposition, these studies typically include measurement of concentration levels of key chemical components as well as precipitation amounts. For dry deposition, analyses also must include meteorological measurements that are used to estimate rate of the actual deposition, or flux. 5 Data representing total deposition loadings (e.g.. total sulfate or nitrate) are what many environmental scientists use for integrated ecological assessments,... 

Sulfates in surface waters are usually present at lower levels, typically 20 to 60 ppm, but the level can rise to several hundred ppm in subsurface waters. If high alkalinity makeup waters also contain high sulfates, the use of sulfuric acid dosing as a treatment to reduce the alkalinity can be ruled out because when the cooling water is cycled up, the total sulfate content can easily exceed the solubility limit of calcium sulfate (solubility is dependent on temperature but is in the range 1800 to 2000 ppm), and scaling readily occurs. 

Surface Sulfate Total Sulfate Sulfate + Hydroxyl... 

All sulfur compounds showed relatively constant profiles throughout the lower fright levels which is consistent with the neutral conditions in the mixed layer. As compared to the data obtained during the ship cruise (Tables I and II) the concentrations in the lowest flight level (30 m) were about 2-3 times lower for DMS, nearly the same for SO2, and about 3 times higher for MSA and nss-SC>42 The fraction of nss-SC>42 to total sulfate at this level was 18%, similar to the results from the ship cruise. The relatively higher concentrations observed for MSA and nss-SC>42 indicate a significant accumulation of aerosol particles in the mixed layer due to the postfrontal inversion between the mixed layer and the free troposphere. 

To calculate the sulfate content, not only the S042 ion as listed in the species distribution but all S(6) species were considered. Most analytical methods determine all S(6) compounds as sulfate and, moreover, also the drinking water standard refers to this rather theoretical total sulfate content. 

Similarly, total sulfate concentration [S04T] is the sum of all the sulfate species in solution ... 

No information is available regarding the metabolism of tetryl in humans. Seven rabbits orally administered 36 mg/kg/day (range of 32.3-40.0 mg/kg/day) for up to 30 days excreted picramic acid in their urine (Zambrano and Mandovano 1956). Picramic acid was not detected in the urine of two control rabbits (the detection limit was 0.05 mg/L). In addition, the ratio of sulfoconjugates to total sulfates increased with duration of treatment in the treated rabbits, but not in the controls. These data support the hypothesis that tetryl is metabolized to picric acid by removal of the methylnitramine complex, and further metabolized to picramic acid by reduction of a nitro group (Zambrano and Mandovano 1956). The increased sulfoconjugates may be caused by conjugation of picramic acid to sulfates. No further data on the metabolic pathway for tetryl were located. 

Studies on humans and dogs show that sulfur dioxide is excreted primarily in the urine as sulfate (Savic et al. 1987 Yokoyama et al. 1971). Yokoyama et al. (1971) exposed dogs via inhalation to 35S02 and determined that 35S was excreted primarily in the urine as sulfate. An average of 84.4% of the urinary radioactivity was exhibited as inorganic sulfate 92.4% was total sulfate. In humans it is estimated that 12-15% of sulfur dioxide absorbed to mucous membranes is desorbed and exhaled (Speizer and Frank 1966). Plasma S-sulfonates are relatively long-lived in the body, with half-life clearance of 4.1 d in rabbits exposed to 10 ppm sulfur dioxide (Gunnison and Palmes 1974). 

Because mercury forms relatively stable hydroxo, sulfato, and chloro complexes in solution, the solubilities and relative stabilities of mercury minerals depend heavily on ambient solution compositions. Figure 4 illustrates the calculated effect of pH and total sulfate on the solubility of schuetteite. The curves take into account all complexes for which data are available in Martell and Smith (18) and precipitation of HgO they cross when changes in solution composition result in changes in dominance among complexes. Schuetteite is quite soluble relative to HgS and elemental mercury under common conditions. 

Fig. 1. Relative importance of various urban sulphate aerosol production mechanisms T = total sulfate A = H2SO4 condensation H = HjOj oxidation O = uncatalyzed oxygen oxidation Q = O3 oxidation F = iron catalyzed oxidation M = manganese catalyzed oxidation C = soot catalyzed oxidation.

Dissolved sulfide in this zone builds up because of its bacterial production. Its maximum concentration is less than the total sulfate reduced because a portion of the H2S reacts with iron and organic matter to form insoluble products. At any depth, the concentration gradient of H2S is kinetically controlled and reflects the balance between the rate of these removal processes, the rate of gain or loss by diffusion, and the rate of its formation by reduction. One of these processes, the production of H2S, must cease when all S04 has been consumed. The net result is a concentration maximum that falls in a range from 1 pM to >10 mM. The depth of maximum pore-water H2S commonly correlates closely with the depth of total S04 depletion. In most environments, H2S persists at measurable concentrations (i.e., greater than a few micromolar) in pore waters to depths of a few centimeters to several meters below the point at which S04 is removed. The essentially total removal of pore-water H2S is a reflection of the availability of excess iron over sulfide sulfur in most sediments (see below). Pyrite content may increase gradually within zone III, but the rate of this increase is most rapid at the top of this zone. Frequently, increases in pyrite cannot confidently be distinguished from scatter in the data within this zone. 

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