Chlorine levels

Industrial Hquid chlorine is routinely analy2ed for moisture, chlorine, other gaseous components, NCl, and mercury foUowing estabHshed procedures (10,79). Moisture and residue content in Hquid chlorine is determined by evaporation at 20°C foUowed by gravimetric measurement of the residue. Eree chlorine levels are estimated quantitatively by thiosulfate titration of iodine Hberated from addition of excess acidified potassium iodide to the gas mixture. 

Corrosion. The primary coal properties affecting corrosion are sulfur and chlorine levels. The range of sulfur levels in Table 2 shows a low of 0.3% for SUFCo and a high of 5.2% for petroleum coke. R F coal has 4.2% sulfur. The highest chlorine level in this group of coals is 0.41% for Pyro No. 9 coal. 

These values assume chlorination in carbon tetrachloride solution under homogeneous conditions favoring random distribution of chlorine atoms along the chain. Viscous reaction conditions, faster chlorine addition rates, lower temperature conditions, etc, can lead to higher AH at equivalent chlorine levels because of more blocky chlorine distribution on the polymer chain. 

The first patent on the chlorination of polyethylene was taken out by ICI in 1938. In the 1940s scientists of that company carried out extensive studies on the chlorination process. The introduction of chlorine atoms onto the polyethylene backbone reduces the ability of the polymer to crystallise and the material becomes rubbery at a chlorine level of about 20%, providing the distribution of the chlorine is random. An increase in the chlorine level beyond this point, and indeed from zero chlorination, causes an increase in the Tg so that at a chlorine level of about 45% the polymer becomes stiff at room temperature. With a further increase still, the polymer becomes brittle. 

Hliiull. In v.tive B 5th ijifcni-.O pr< SM re ViilvL-. fail [jpai C)peration Excessive chlorine How to Tower Water Basin - high chlorine level to cooling water -potential for excessive corrosion in cooling water system Rotameter Relief valve an pressure check valve outlet in Nnilk-... 

Sodium metabisulfate may be used to chemically reduce high chlorine content in order to prevent softener resin damage. Resins can tolerate chlorine levels less than 0..5 pprn. 

If the water is found fit for consumption, with respect to both its mineral and biological content, the problem of sanitization can still arise. Public supply invariably has a very small residual chlorine level. This suppresses biological growth and maintains water quality even when the line is stagnant. As with other forms of treatment, the scale of private supply is usually too small to allow good control of chlorinating equipment. 

The pH of the water is checked again and made slightly basic to reduce acid corrosion of the pipes. At this point, a disinfectant, usually chlorine, is added. In the United States, the chlorine level is required to be greater than 1 g of Cl2 per 1000 kg (1 ppm by mass) of water at the point of consumption. In water, chlorine forms hypochlorous acid, which is highly toxic to bacteria ... 

This reaction is called the breakpoint chlorination the combined chlorine level, which was rising as more chlorine was added, now drops suddenly. Free chlorine then rises without a corresponding rise in combined chlorine. This indicates that the pool pollution has been successfully oxidized by chlorine. 

It is used in excess of the amount necessary (e.g., using materials containing chlorine as an ingredient in a process requiring chlorine, but in excess of the required chlorine levels). 

The fire resistance is inherently good and can be improved by an appropriate formulation, but PVC contains a high chlorine level that is released in the event of combustion and can involve corrosion during processing. The thermal behaviour is limited. 

Microorganisms (especially bacteria) are capable of producing strains which are tolerant to normal chlorine treatment levels. This can be overcome by employing higher chlorine levels however, this can lead to the formation of unpleasant flavours and odours due to the formation of chlorophenols and other halocarbons. 

Chlorine was injected periodically from a cylinder containing 5% CI2 gas in dry nitrogen. The gas mixture was sparged into the system through two 30 mm fritter glass discs of medium porosity. Chlorine dissipation rates were found to be slow and chlorine levels could be maintained reasonably constant ( 5%) by injecting fresh gas at about 12 hour intervals. Flow rates and injection times were established by analysis of chamber contents. 

Two chlorine levels were arbitrarily selected for this work. 

Initially all membranes were exposed to 3 ppm chlorine in buffer solutions at pH levels of 3.0, 5.8, and 8.6 for three weeks. Both cellulose acetate type membranes C-2 and V-1 were unaffected by chlorine under these conditions. Continued exposure at higher chlorine levels did not alter baseline membrane performance. For example, membrane C-2 exposed to 125 ppm chlorine for 10 days at pH 3 continued to perform at baseline levels. In subsequent work, cellulose acetate membranes were also found to be unresponsive to bromine, iodine, and chlorine dioxide. It can be generally concluded that cellulose acetate type membranes are halogen resistant. 

In a related case, FT-30 membrane elements were placed on chlorinated seawater feed at OWRT s Wrightsville Beach Test Facility. Flux and salt rejection were stable for 2000 hours at 0.5 to 1.0 ppm chlorine exposure. Chlorine attack did become noticeable after 2000 hours, and salt rejection had dropped to 97 percent at 2500 hours while flux increased significantly. Long term laboratory trials at different chlorine levels led to the conclusion that the membrane will withstand 0.2 ppm chlorine in sodium chloride solutions at pH 7 for more than a year of continuous exposure. 

The Bowmans lignite has the highest sodium and chlorine levels of 1.86% and 1.98% respectively. 

Record the pH, conductivity (and/or salinity), and chlorine levels, and confirm that the values comply with the ranges established for the laboratory s system/tank water. 

There are several reasons for the dramatic ozone destruction (see Fig. 2.17) low temperatures may have prolonged the presence of polar stratospheric clouds, which play a key role in the ozone destruction, the polar vortex was very stable, there were increased sulfate aerosols from the 1991 Mount Pinatubo volcanic eruption, which also contribute to heterogeneous chemistry, and chlorine levels had continued to increase. These issues are treated in more detail shortly. 

Use of the resins with samples containing free chlorine residual is not recommended. Cheh (35) suggested that chlorine may produce mutagenic artifacts on XAD-4. Our experiment with 2-mg/L chlorine residual appeared to promote the release of irreversibly adsorbed spiked standards Six model compounds were recovered at levels several times higher than those observed in normal blank runs. In addition, many resin artifacts were eluted after exposure to this chlorine level, primarily aromatic and aliphatic acids, aldehydes, and ketones. Stoichiometric dechlorination (ferrous ion) is therefore recommended in order to avoid cross contamination between samples and inclusion of undesirable resin artifacts in the residue to be bioassayed. 

Isocyanurates can be effective for small cooling systems, as the slow-release chemistry tends to permit improved control over the free chlorine level, unlike bleach and calcium hypochlorite. Nevertheless, it should be remembered that isocyanurates contain a high level of available chlorine and, if the cooling system dynamics or chemistry changes, the potential exists for a sudden high concentration of free chlorine, with all the inherent corrosion risk that this entails. 

Recently, Wikstrom et al. (1996) studied formation of CDDs, CDFs, and chlorobenzenes in the combustion process. These authors monitored combustion of an artificial fuel where the chlorine level and source were varied in the artificial waste. Different levels of organic chlorine (PVC) and inorganic chlorine (CaCl2 6H20) were added to the fuel. When the level of chlorine in the fuel was <1%, there was no correlation between the quantities of CDDs, CDFs, and chlorobenzenes present. However, when the chlorine level was >1%, increased formation rates were noted for CDDs, CDFs, and chlorobenzenes. 

Environmental demands and are as follows (a) improved fuel economy (reduced viscosities, reduced friction, special viscosity improvers), (b) reduced oil consumption (unconventional base oils, improved seal compatibility), (c) extended oil life (improved thermo-oxidative stability), (d) extended engine life (improved detergents and antiwear additives), (e) beneficial effects on emission/after treatment hardware (new additives), (f) technological and environmental sensitivity (no halogens, limited metal types/concentrations, new organic compounds), (g) recyclability (limitations the polycyclic aromatic hydrocarbons content and high chlorine levels (Havet et al., 2001 Waara et al., 2001). 

Anita K. is a lifeguard at a large public swimming pool. One of her jobs is to test pH and chlorine levels in the pool four times a day. She enters these measurements into a log. Chlorine and pH levels in a swimming... 

Today, when Anita checked the pH and chlorine levels she found an acceptable chlorine level, but a pH of 7.8, which is above the acceptable level. She enters this value in the log and goes to the pump house to adjust the pumping rate on the sodium hydroxide. (ABC Water, p. 159)... 

The system is kept automatically controlled at free chlorine levels (DPD1) of less than 0.4 ppm and total disinfectants (DPD3) of less than 1.2 ppm. There is a total absence of any chloramines. 

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