First of all, use of Best Available Techniques includes taking measures to suppress by-product formation. This makes both economic and environmental sense.
Techniques for the prevention of emissions to atmosphere include capturing vent gases, which are treated by scrubbing, filtration for removal of particulate matter, and subsequently by thermal oxidation in dedicated units or in a hazardous waste incinerator.
Techniques for the prevention of discharges into water include appropriate recycling of streams back into the process, stripping of volatile pollutants, alkaline treatment of streams containing less volatile chlorinated organics to convert them to inorganic chloride. Biological treatment of the pre-treated wastes reduces residual pollutants to acceptable levels, for example by concentrating them into the activated sludge for subsequent solid waste treatment. Any dioxins produced and not destroyed within the process are segregated into the solid waste stream.
Heavy end tars from distillation are recycled into the process or destroyed by incineration or equivalent technologies. The chlorine is recovered in the form of HCl and usually recycled into the production process.
All solid wastes containing organic by-products, including spent catalyst from oxychlorination, are appropriately treated as hazardous wastes because of their organics content.
