Dioxins are a class of substances with persistent pollution, with its highly toxic, the small amount of them can cause serious damage to health or fatal, so they has become the focus of public attention in recent years. Dioxins are very stable compounds, which appear in a colorless solid at room temperature; it will accumulate in fat after entering human body with its high lipophilicity; In addition, it is extremely difficult to remove once the pollution occurs, because the strong bond between it and the soil or other particulate material.

 

The most effective way to remove dioxins is still the selective oxidation-reduction, experimental proposed a preparing method of tungsten trioxide denitration catalyst which with dioxin removable; also the anti-sulfur poisoning is improved, and possess the good catalytic activity at the same time. It is prepared as the follow steps:

 

1. Successively add the equal amount of titanium dioxide powder and carbon nanotubes into the dilute ammonia to form the carrier mixture with stirring well, then transferred to the ultrasonic cleaning machine for an ultrasonic treatment;

2. Dissolve ammonium metavanadate, ammonium sulfate, ammonium metatungstate in the dilute aqueous ammonia in turns to form of a mixed solution of the active ingredient, then thoroughly stirred under heating, transferred into a rotary evaporator furnace for drying to give a mixture of the active ingredient;

3. Successively add the active ingredient mixture, glass fiber, cellulose and polyacrylic acid  into the mixed carrier to form a catalyst mixture, heat with stirring to dry and stop until the catalyst mixture of a moisture content of about 30%;

4. Get the tungsten trioxide denitration catalyst products with dioxins removable by extruding, drying, calcining the catalyst mixture.

 

This kind of catalyst is constituted by the following components: 1.2% of vanadium pentoxide, 7% of vanadium oxide sulfate, 1.5% of tungsten trioxide, 2.5% of glass fiber, 1.5% of polyacrylic acid cellulose, 1.1% of cerium sulfate, 14% of manganese sulfate, the rests are carriers (titanium dioxide and carbon nanotubes with the mass ratio of 1:1).