Utilization of industrial wastes for sorption of toxic gases

The purification of exhaust gases of some industries by solid wastes of other enterprises is promising and up-to-date in environmental protection. This paper presents the research results on purification of waste gases from ammonia and benzene by wastes from thermal power engineering (fly ash) and chemical industry (secondary polytetrafluoroethylene). Operation of heat power industry plants, which are powered by bituminous coal, results in producing fly ash which is to be stored in special ash ponds. Ash ponds occupy large areas and significantly burden the local ecosystem. Using ash in building, sound-absorbing, and heat insulating materials' production reduces the volumes of ahs ponds. Fly ash can be used as a base for heterogeneous catalysts. Fly ash can also be used in zeolite production and for soil structure improvement. A number of studies provide positive results of wastewater treatment from oil products and heavy metal ions, as well as absorption of air sulfur(IV) oxide. We propose fly ash using as a sorbent for ammonia adsorbing from exhaust gases in nitric acid and nitrogen fertil-izers production. The adsorbate can be applied as a fertilizer for acid soils. Secondary polytetrafluoroethylene is a co-product of polytetrafluoroethylene production. It can be converted into ultradisperse powder with particle sizes of 0.20-1.35 mu m by method of exhaustive fluoridation; the powder applies to a sponge material. The resulting sorbent can be used to extract benzene vapors from the exhaust gases of industries using benzene, for example, as a solvent. Compared to activated carbon, the developed sorbent effectively removes benzene vapors from exhaust gases. Over time, the purification efficiency of heated gases decreases to almost zero. Presumably this is due to liquid benzene fraction condensation on the sorbent surface.