Water chloride concentration

Alio Cooling water chloride concentration C WTR CHL N 13 parts per million... 

A spike recovery for the analysis of chloride in well water was performed by adding 5.00 mb of a 25,000-ppm solution of Ck to a 500-mL volumetric flask and diluting to volume with the sample. Analysis of the sample and the spiked sample resulted in chloride concentrations of 183 ppm and 409 ppm, respectively. Determine the percent recovery of the spike. 

The variation of the dielectric constant of the HCl + H2O mixtures is not appreciably different from that of pure water (78.30) at 25°C until the hydrogen chloride concentration teaches a minimum of 0.2%. It increases slightly over the dielectric constant of water as the concentration increases. 

Chlorine. Nearly all chlorine compounds are readily soluble in water. As a result, the major reservoir for this element in Figure 1 is the ocean (5). Chloride, as noted earHer, is naturally present at low levels in rain and snow, especially over and near the oceans. Widespread increases in chloride concentration in mnoff in much of the United States can be attributed to the extensive use of sodium chloride and calcium chloride for deicing of streets and highways. Ref. 19 points out the importance of the increased use of deicing salt as a cause of increased chloride concentrations in streams of the northeastern United States and the role of this factor in the chloride trends in Lake Ontario. Increases in chloride concentration also can occur as a result of disposal of sewage, oil field brines, and various kinds of industrial waste. Thus, chloride concentration trends also can be considered as an index of the alternation of streamwater chemistry by human development in the industrialized sections of the world. Although chlorine is an essential element for animal nutrition, it is of less importance for other life forms. 

Chloride. Chloride is common in freshwater because almost all chloride salts are very soluble in water. Its concentration is generally lO " to 10 M. Chloride can be titrated with mercuric nitrate. Diphenylcarbazone, which forms a purple complex with the excess mercuric ions at pH 2.3—2.8, is used as the indicator. The pH should be controlled to 0.1 pH unit. Bromide and iodide are the principal interferences, whereas chromate, ferric, and sulfite ions interfere at levels greater than 10 mg/L. Chloride can also be deterrnined by a colorimetric method based on the displacement of thiocyanate ion from mercuric thiocyanate by chloride ion. The Hberated SCN reacts with ferric ion to form the colored complex of ferric thiocyanate. The method is suitable for chloride concentrations from 10 to 10 M. 

A notable example of controlled water reuse was utilization of secondary sewage effluent from the Back River Wastewater Treatment Plant in Baltimore by the Sparrows Point Works of Bethlehem Steel (6). The Sparrows Point plant was suppHed primarily by weUs located near the brackish waters of Baltimore harbor. Increased draft on the weUs had led to saltwater intmsion. Water with chloride concentration as high as 10 mg/L is unsuitable for many steelmaking operations. Rollers, for example, are pitted by such waters. However, treated effluent from the Back River Plant can be used for some operations, such as coke quenching, and >4 x 10 m /d (10 gal/d) are piped 13 km to Sparrows Point. This arrangement has proved economical to both parties for >40 yr. 

Adequate venting of exchangers is required both for proper operation and to reduce corrosion. Improper venting of the water side of exchangers can cause alternate wetting and drying and accompanying chloride concentration, which is particularly destructive to the series 300 stainless steels. 

As metal ion concentration increases in the crevice, a net positive charge accumulates in the crevice electrolyte. This attracts negatively charged ions dissolved in the water. Chloride, sulfate, and other anions spontaneously concentrate in the crevice (Figs. 2.4 and 2.5). Hydrolysis produces acids in the crevice, accelerating attack (Reactions 2.5 and 2.6). Studies have shown that the crevice pH can decrease to 2 or less in salt solutions having a neutral pH. 

In sea water with a pH of 8, crevice pH may fall helow 1 and chloride concentration can be many times greater than in the water. The crevice environment becomes more and more corrosive with time as acidic anions concentrate within. Areas immediately adjacent to the crevice receive ever-increasing numbers of electrons from the crevice. Hydroxyl ion formation increases just outside the crevice—locally increasing pH and decreasing attack there (Reaction 2.2). Corrosion inside the crevice becomes more severe with time due to the spontaneous concentration of acidic anion. Accelerating corrosion is referred... 

The amount of chloride, sulfate, thiosulfate, or other aggressive anions dissolved in water necessary to produce noticeable attack depends on many interrelated factors. Extraordinarily, if the water is quite aggressive, general corrosion may occur so rapidly outside the crevice that concentration differences cannot easily develop between the crevice interior and exterior. However, it is usually safe to assume that as the concentration of aggressive anions increases in solution, crevice attack is stimulated. Seawater chloride concentrations produce severe attack in most stainless crevices in a few weeks. 

Calcium carbonate has normal pH and inverse temperature solubilities. Hence, such deposits readily form as pH and water temperature rise. Copper carbonate can form beneath deposit accumulations, producing a friable bluish-white corrosion product (Fig. 4.17). Beneath the carbonate, sparkling, ruby-red cuprous oxide crystals will often be found on copper alloys (Fig. 4.18). The cuprous oxide is friable, as these crystals are small and do not readily cling to one another or other surfaces (Fig. 4.19). If chloride concentrations are high, a white copper chloride corrosion product may be present beneath the cuprous oxide layer. However, experience shows that copper chloride accumulation is usually slight relative to other corrosion product masses in most natural waters. 

Figure 7.22 Pitting on a 304 stainless steel coupon caused by acidic, chloride-containing water condensating and evaporating. High chloride concentrations were produced locally.

To determine cooling water system flows, use a heat and material balance and a chloride balance (concentration ratio is usually calculated from chloride concentrations). 

There were placed 120 g of Lthree-necked flask equipped with a stirrer thermometer and methanol/dry ice cooling and 1.5 liters of liquid ammonia were allowed to enter at -40°C. Then there were added under continuous cooling 50 g (2.17 mols) of sodium metal in portions of 1 to 2 g during the course of one hour. The end of the reaction was recognized by the continuation of the blue color. After the end of the reaction the excess sodium was destroyed by the addition of ammonium chloride and the ammonia vaporized at normal pressure. The residue was taken up in 500 ml of water and concentrated in a vacuum to 200 ml in order to remove residual ammonia, and again treated with 300 ml of water. The entire operations were carried out under a nitrogen atmosphere. 

The reaction mixture was poured into 25 ml of water and the mixture made strongly basic with ION sodium hydroxide solution. The mixture was extracted 3 times with 50 ml portions of benzene, the combined extracts washed with water and concentrated to a volume of approximately 50 ml. The solution was saturated with dry hydrogen chloride and the white crystalline product collected and dried. The yield of product, MP 251.6° to 252.6°C (dec.) was 2.5 g. Recrystallization from a mixture of absolute alcohol and absolute ether gave a product, MP 252.6° to 253.6°C. A sample was analyzed after drying for 7 hours at 110°C over phosphorus pentoxide in vacuo. 

The purity of ionic liquids is a key parameter, especially when they are used as solvents for transition metal complexes (see Section 5.2). The presence of impurities arising from their mode of preparation can change their physical and chemical properties. Even trace amounts of impurities (e.g., Lewis bases, water, chloride anion) can poison the active catalyst, due to its generally low concentration in the solvent. The control of ionic liquid quality is thus of utmost importance. 

Assume that a given cooling tower is designed to reduce the incoming temperature of 10,000 gpm by 25°F (range). Then, assume that the level of chlorides in the make-up water is 250 ppm, and we do not want that level to go beyond 750 ppm in the circulating water. Allowable concentration ratio is 750/250 = 3. The approximate... 

The oxide coatings are porous and therefore the limitations on operating voltage for platinised titanium anodes apply as well to the oxide-coated titanium electrodes. It has been reported that breakdown of mixed metal oxide anodes may occur at 50-60 V in low-chloride concentration water but at only 10 V in chloride-rich environments . 

Table 21.26 CortipositionS of natural waters arranged ini increasing chloride concentrations...

Table 21.26 Compositions of natural waters arranged in increasing chloride concentration (concentration in p.p.m.)...

Suppose 10 ml of 1.0 M AgNOs is diluted to one liter with tap water. If the chloride concentration in the tap water is about 10-1 M, will a precipitate form ... 

The test described in Problem 23 does not give a precipitate if the laboratory distilled water is used. What is the maximum chloride concentration that could be present ... 

Water Extract with methylene chloride concentrate cleanup on silica gel GC/FPD No data 93 EPA1980d o D (/>... 

Preparation of 3 - Chloro-6 -cyclohexylaminoJluoran (85a). A mixture of 3, 6 -dichlorofluoran (0.1 mol), cyclohexylamine hydrochloride (0.15 mol), zinc chloride (0.3 mol), and zinc oxide (0.2 mol) was fused at 190-200 °C for 4 h. After being cooled, the solidified mixture was powdered, heated with 4% hydrochloric acid (1000 ml) to dissolve zinc chloride, and filtered. Then, the filter cake was refluxed with a mixture of toluene (400ml) and 5% aqueous sodium hydroxide (100 ml) for 1 h. The toluene layer was separated, washed with hot water, and concentrated. The residue was refluxed with methanol (200ml) for 1 h. After being cooled, the precipitate was filtered off, washed with methanol, and dried to give 3 -chloro-6 -cyclohexylaminofluoran in 60% yield as an off-white powder, mp 178-181 °C. 

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