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Application specific alarm sizing and coverage leads to a more effective and economical warning system.


Introduction textChlorine is the lowest cost and most widely used oxidizing disinfectant in the treatment of wastewater. It serves to neutralize infectious agents such as bacteria, protozoa, parasitic worms, and viruses in the wastewater treatment plant's effluent stream prior to its discharge to the environment. Chlorine is also a highly corrosive and toxic chemical. Although there is some debate about the health impact of ingesting chlorine, it is certainly not as dangerous as ingesting the infectious agents that it destroys. 

A burning sensation is the result of contact with chlorine and the severity of this is proportional to its concentration and the duration of exposure.

 

At wastewater treatment plants, chlorine is typically injected as a gas into the water to be treated. Bulk chlorine is stored as a liquefied compressed gas or as an unpressurized liquid consisting of sodium hypochlorite dissolved in water (also known as bleach). Liquid chlorine is evaporated into a gas prior to its use in wastewater treatment. 

The concentration of chlorine used varies on the application from low for drinking water (< 3 ppm), to medium for a swimming pool, to high for wastewater treatment (5 - 20 ppm). Exposure time and other chemical characteristics have an influence on the effectiveness of chlorine disinfection. Since chlorine can also negatively impact fish and wildlife, there are limits as to how much can be present in the discharge stream. To bring effluent streams within discharge limits (<0.02 ppm), de-chlorination is commonly achieved after the disinfection has taken place by injecting sulphur dioxide gas into the water.

The density of chlorine gas is approximately 2.5 times greater t an air - meaning that it will remain near the ground in areas with little air movement and pose a significant inhalation risk. 

A chlorine gas leak within the confines of a building in a water or wastewater treatment facility represents a safety hazard that can quickly lead to injury or death.

PATROL_flashing_sounder

Fig : Pfannenberg PATROL Flashing Sounder Installed In Water Wastewater Treatment Facility

 
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