Chlorine maximum concentration

A major disadvantage of this system is the limitation of the single-pass gas-chlorination phase. Unless increased pressure is used, this equipment is unable to achieve higher concentrations of chlorine as an aid to a more complete and controllable reaction with the chlorite ion. The French have developed a variation of this process using a multiple-pass enrichment loop on the chlorinator to achieve a much higher concentration of chlorine and thereby quickly attain the optimum pH for maximum conversion to chlorine dioxide. By using a multiple-pass recirculation system, the chlorine solution concentrates to a level of 5-6 g/1. At this concentration, the pH of the solution reduces to 3.0 and thereby provides the low pH level necessary for efficient chlorine dioxide production. A single pass results in a chlorine concentration in water of about 1 g/1, which produces a pH of 4 to 5. If sodium chlorite solution is added at this pH, only about 60 percent yield of chlorine dioxide is achieved. The remainder is unreacted chlorine (in solution) and... 

Chlorine is to be removed from a vent stream by scrubbing with a 5 per cent w/w aqueous solution of sodium hydroxide. The vent stream is essential nitrogen, with a maximum concentration of 5.5 per cent w/w chlorine. The concentration of chlorine leaving the scrubber must be less than 50 ppm by weight. The maximum flow-rate of the vent stream to the scrubber will be 4500 kg/h. Design a suitable packed column for this duty. The column will operate at 1.1 bar and ambient temperature. If necessary, the aqueous stream may be recirculated to maintain a suitable wetting rate. 

A particular release of chlorine gas has resulted in the concentration profile given in Figure 5-18 for the cloud moving downwind along the ground. This is the concentration recorded at a fixed location as the cloud passes. The concentration increases linearly to a maximum concentration Cmax and then decreases linearly to zero. 

Calcium chlorate Calcium chlorite Calcium hypochlorite Calcium perchlorate Calcium permanganate Calcium peroxide Chloric acid (10 percent maximum concentration) Chlorine... 

Haloaldehydes are formed primarily with chlorine or chloramine disinfection, but they are increased in formation with preozonation. In the Nationwide Occurrence Study, haloaldehydes were the third largest DBP class by weight (behind THMs and HAAs) of all the DBPs studied. Dichloroacetaldehyde was the most abundant of these haloaldehydes, with a maximum concentration of 16 pg/L. Before this study, chloral hydrate (trichloroacetaldehyde) was the only commonly measured haloaldehyde, and it was included in the ICR. Chloral hydrate and monochloroacetaldehyde are mutagenic in vitro [1], and tribromoacetaldehyde and chloral hydrate were recently found to be genotoxic in human cells [72]. 

Under USEPA s BIF mle, manufacturers are required to closely monitor numerous conditions in the kiln and to observe limits on the following aspects of the process (a) the maximum feed rate of hazardous waste fuel (b) the maximum feed rate of metals from both raw materials and fuels (c) the maximum feed rate of chlorine from raw materials and fuels (d) the maximum feed rate of raw materials (e) the maximum temperature at the inlet to the air pollution control devices (f) the maximum concentration of carbon monoxide and total hydrocarbons in the flue gas (g) the maximum temperature in the combustion zone or minimum temperature at the kiln inlet and (h) any decrease of pressure at the baghouses or any decline in the strength of the electric field of electrostatic precipitators (both are types of air pollution control devices). 

Chlorine dioxide is added to drinking water to protect people from harmful bacteria and other microorganisms. Most people will be exposed to chlorine dioxide and its disinfection by-product, chlorite ions, when they drink water that has been treated with chlorine dioxide. The EPA has set the maximum concentration of chlorine dioxide and chlorite ion in drinking water at 0.8 and 1.0 milligrams per liter (mg/L), respectively. However, the concentrations of chlorine dioxide and chlorite ion in your drinking water may be lower or higher than these levels. For additional information about how you might be exposed to chlorine dioxide and chlorite, see Chapter 6. 

EPA has set the maximum concentration of chlorine dioxide and chlorite ion for drinking waters at 0.8 and 1.0 mg/L, respectively. However, the concentrations of chlorine dioxide and chlorite ion in drinking water may be higher or lower than these levels. 

Where chlorine dioxide is used, it is normally advantageous to feed it directly to the recirculating water pump suction to ensure that the maximum concentration is available to scour the cooling tower distribution decks and other areas that may be subject to heavy fouling by algal slimes. 

Exposure Registries. New York State has instituted a Heavy Metals Registry that monitors occupational exposure to heavy metals, including mercury. Cases are reported when mercury exposure is equal to or exceeds 50 g/L (ppb) in blood or 20 g/L (ppb) in urine. Between 1982 and 1986, 1,000 cases of mercury exposure were reported and linked to 47 companies. Most exposures (494 cases) occurred in workers in the alkali and chlorine industry, where mercury is used as a cathode because exposure occurs when the cells are opened the median blood mercury concentration was 76 g/L (ppb) (maximum concentration 916 g/L [ppb]). The second most frequent exposure category (213 cases) was the manufacture of industrial instruments, such as the manual assembly and fabrication of thermometers median blood mercury concentration was 145 g/L (ppb) and the maximum concentration was 889 g/L (ppb) (Baser and Marion 1990). 

Information regarding PCB distribution in animals after inhalation exposure is limited. Rats exposed to 30 g/m of an aerosol of a PCB mixture (Pydraul A 200,42% chlorine) had 52,14, and 9 pg PCB/g tissue in the liver, adipose, and brain, respectively, after 30 minutes of exposure (Benthe et al. 1972). The concentration of total PCBs attained in the liver after 2 hours of exposure was 70 pg/g. PCB levels in the liver reached a maximum 2 hours after exposure and slowly decUned to less than half of the maximum 12 hours after exposure. Analysis of retroperitoneal adipose tissue revealed oidy trace amounts of PCBs immediately after exposure only a slight increase in concentration was detected after 12 hours. Maximum concentration in adipose tissue was attained 36 hours after exposure. In contrast to adipose tissue, PCBs were detected in the brain immediately after exposure, reached a maximum 24 hours after exposure, and slowly declined thereafter. 

Maximum concentrations of hypochlorous acid are obtained by treating pure liquid chlorine(I) oxide with water at 0°. Lower concentrations result from use of the gaseous oxide under reduced pressure or from use of solutions of the oxide in carbon tetrachloride. The last procedure is convenient for acid concentrations up to 5 M. The reaction is nearly quantitative, the equilibrium concentrations of hypochlorous acid and chlorine (I) oxide in the two phases at 0° being calculated from the data of... 

Table 20.9 Concentrations of CPs in drinking water from Labin (sampling 1989) [8] and maximum concentrations in chlorinated spring waters supplying waterworks of Labin (sampling period 1989-1990)...

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