Available chlorine

The total concentration or amount of chlorine-based oxidants is often expressed as available chorine or less frequendy as active chlorine. Available chlorine is the equivalent concentration or amount of Cl needed to make the oxidant according to equations 1—4. Active chlorine is the equivalent concentration or amount of Cl atoms that can accept two electrons. This is a convention, not a description of the reaction mechanism of the oxidant. Because Cl only accepts two electrons as does HOCl and monochloramines, it only has one active Cl atom according to the definition. Thus the active chlorine is always one-half of the available chlorine. The available chlorine is usually measured by iodomettic titration (7,8). The weight of available chlorine can also be calculated by equation 5. 

Table 7.5 Comparison of costs of tail-gas recovery methods based on field tests of membranes (16 tonnes day 1 chlorine available at 690kPa). 

This demand will reduce the amount of chlorine available for microbiological control and lead to slime growth, especially in the tower basin and water distribution system, with biofilms and under-deposit corrosion being common effects of this problem. 

For bromine to act as a biocide in the most efficient manner, there must always be sufficient free chlorine available in the cooling water to enable HOBr to be formed from all the available bromine compounds (e.g., bromamines). This requires a higher ratio of total chlorine to bromine than normally available with other bromine technologies. 

Crane Co. Chlorine. Available online. URL http //www. resistoflex.com/chlorine graphs.htm. Accessed on July 2, 2007. 

Calcium hypochlorite is available in powder or granular forms and compressed tablets or pellets. Depending upon the source of the chemical, a wide variety of container sizes and shapes are available. Because it can oxidize other materials, calcium hypochlorite should be stored in a cool dry place and in corrosion-resistant containers. High-test calcium hypochlorite, HTH, contains about 70% chlorine. (Available chlorine will be defined later.)... 

Available chlorine. The strength of a chlorine disinfectant is measured in terms of available chlorine. Available chlorine is defined as the ratio of the mass of chlorine to the mass of the disinfectant that has the same unit of oxidizing power as chlorine. The unit of disinfecting power of chlorine may be found as follows in terms of one mole of electrons ... 

Sodium hypochlorite solutions contain 12 to 15% and calcium hypochlorite 3 to 3.8% of available chlorine. Available chlorine is the quantity of chlorine produced by adding hydrochloric acid, relative to the weight of the product ... 

Sodium hypochlorite solution is more costly per weight (pound) of available chlorine and does not contain the high concentrations of chlorine available from chlorine gas. However, the handling and storage costs are lower than for chlorine gas. 

By combining oxychlorination, which consumes hydrochloric add, with the direct chlorination of ethylene the by-production of chlorinated wastes can be limited and the production of vinyl chloride adjusted to the chlorine availabilities. Different variants can be considered, including the following two ... 

The amount of chlorine available in a domestic bleach which contains sodium chlorate(l) can be found by allowing the bleach to react with an iodide solution to form iodine, and then titrating with thiosulphate solution ... 

Bleaching powders (7778-54-3) are complex, solid mixtures of calcium hypochlorite, calcium chloride, calcium hydroxide, and their hydrates. They are applied as dry powders to moist or wet environments (e.g., septic tanks, soils, sewers) where they form a solution with the water making chlorine available for oxidation. 

A broad range of halogenated flame retarding compoimds can be used in conjunction with antimony trioxide, typically chlorinated paraffins and chlorinated cycloaliphatic compoimds, brominated aromatic compounds and brominated phosphates. However, the major application for antimony trioxide in terms of consumption is in flexible PVC, where the chlorine available from the polymer is sufficient to provide the desired level of flame retardancy. 

Available chlorine is the amount of chlorine needed to make the hypochlorite in a solution or a solid. It is the amount of hypochlorite compound multiplied by the number of hypochlorite groups per molecule divided by its molecular weight times the molecular weight of chlorine. The last three terms are combined to derive the theoretical available chlorine factors as shown in Table 24.1. These factors multiplied by the amount of hypochlorite compound equals available chlorine. Available chlorine is usually measured by iodometric titration. It is a convenient way of expressing the total activity of mixtures without knowing the concentrations of the components. 

The composition of the product mixture depends on the amount of chlorine available and the length of time the reaction is allowed to run. If we use a sufficient amount of chlorine and allow the reaction to run long enough, all the methane can be converted into carbon tetrachloride. However, measuring the product... 

Antimony will react until there s no more chlorine available. Some antimony will be left. How much You know how much antimony you started with. If you knew how much you used, you could subtract what was used from what you had at the... 

Chloramines also pose a risk to polyamide, composite membranes (see Chapter 8.5.2.1.2). Chloramines are virtually always in equilibrium with free chlorine. Although the tolerance of the FilmTec FT30 membrane to pure chloramines is 300,000 ppm-hrs, FilmTec still recommends that influent water with chloramines be dechlorinated prior to the membrane. In most cases, ammonia is added to chlorine to generate chloramines. This leaves open the possibility that there is still some free chlorine available. The most successful chloramine applications seem to be found in wastewater systems with a resident concentration of ammonia, to which chlorine is added to make the chloramines. 

When there is insufficient chlorine available in the rubber compound to improve flame retardancy, chlorinated paraffins are sometimes added as a relatively inexpensive source of halogen. CP also functions as a plasticizer in rubber compounding. Chlorinated paraffins decompose into toxic gases at lower temperatures than other more stable chlorine donors that are commercially available. Therefore chlorinated paraffins cannot be used in rubber compound mixes that are going to be exposed to high mixing dump temperatures because they will emit toxic gases in the workplace, which pose a hazard to workers In the factory. 

Based on the chlorine content of the polymer and equivalent weight of the amine Hydrochlorides shown hydrochlorides in parentheses Based on chlorine available Trace... 

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