Presentation on theme: "Times Beach, Missouri Dioxin contamination and a controversial clean-up operation."— Presentation transcript:
Times Beach, Missouri Dioxin contamination and a controversial clean-up operation
An overview Times Beach is a small town in South-western Missouri. Between 1970 and 1972, large amounts of hexachlorophene were produced by a pharmaceutical and chemical company. The resulting waste from this production contained TCDD. This waste was then mixed with oil and sprayed along the roads in Times Beach in an effort to control dust.
Continued … Soon after the chemical was sprayed along roads, animals died and children fell sick. In 1982 soil tests found that the town was being poisoned by dioxin. Over 500 families were told to evacuate their homes while additional tests were carried out.
The Chosen Solution … On site Incineration. Contaminated soil was shredded, screened and treated with lime. Incineration system comprised of a primary chamber, secondary combustion chamber and thermal relief vent.
Description Consists of a rotary kiln. Contaminated soil is feed into kiln and the dioxins are burnt. Ash is discharged at lower end of kiln. Flue gases from the kiln are passed on to the Secondary Combustion Chamber for complete destruction.
Rotary kiln with secondary combustion chamber
Secondary Combustion Chamber Vertical refractory lined vessel which heats the flue gas to complete combustion. Heats the vaporized dioxins until they are completely vaporised.
Thermal Relief Vent Attached vessel at the top of the secondary combustion chamber. Dissipates positive pressure incase if failure of the draft fans.
Conclusion The use of an incinerator was a controversial decision. On March 20, 1990, an electrical power-cut caused a discharge of dioxin-contaminated pollutants. Different groups formed opposing the incinerator. The experience at Times beach has led to new laws regarding chemical waste disposal.