All over the world there are different attempts to use slag and ash from the heat power stations, working at a coal, slates, black oil, etc. Among them attempts to make curbing, barrier reeves and blocks for construction, to include them into asphalt and to use for other road coverings. But slag and ash are rather toxic, their toxicity develops of toxicity of polyaromatic hydrocarbons (basically benz(a)pyrene), heavy metals and unidentified organic toxicants. Concentration of the heavy metals oxides in slag and ash in 100-1000 times (sometimes more) is higher than in burning fuel. In the next table presented data contains a significant amount of heavy metals in ash and slag (1) of coal heat power station (mg / kg of fuel):
Coal heat power station
It is necessary to note, that flying ash includes also set of extremely dangerous substances. Detailed research of toxic properties of flying ash has been carried out in Netherlands (2).
Polyaromatic hydrocarbons are dangerous carcinogens (3). Toxic heavy metals are discharged in the form of salts or oxides, that is in a steady √ state condition, and can be in ash for uncertain time (years). Getting in an organism of the person, lead to demage of liver and gastrointestinal tract, autoimmune joint diseases, diseases of nervous system and psychoneurological frustration, genetic changes at descendants, increase of sensitivity to ionizing radiation, an osteoporosis of tubular bones (4, 5).
In review article it is specified, that " If earlier many were afraid, that mercury and other harmful substances from ash will pollute air now it is proved, that bricks from ash, on the contrary, absorb mercury vapors ". Thus, authors of article mark, that the offered technology does not provide preliminary clearing raw material (ash and slag) from harmful substances, but only "encupsulate" them (including heavy metals) in the weight of formed products which is not passing, in opinion of authors, toxicants in to environment. However, a number of substances, for example, sulfur, can cause degradation of bricks that results in penetration pollutants in an environment. Besides toxic metals in the certain conditions can be washed away by rains, for example, at change of acidity of rain water " on meteorological conditions " (3). As the specified harmful substances concern to rather steady toxicants, most likely the bricks made with utilizing this technology will be toxic many decades and a poison will get not only to our grandsons, but also great-great-grandsons. Thus, even positive results of researches do not give the bases for wide industrial use of the specified technology. Long-term quality check of bricks in experimental buildings and constructions is required.
1. A. Buekens, J. Schoeters, " Thermal Methods in Waste Disposal " EEC, Brussels, 1984.
2. Th. Helder, E. Stuttrheim, K. Olie. Chemosphere, Vol. 11, No. 10, pp.952-972, 1982.
3 Yufit S. S .Incinerate factories - dump in the sky. Ecoline, 1998.
4. Afonin D.G., Ragulskaya M.V. Feature of adaptation of an organism the person to technogenic to factors of a modern megacity. 08.07.2003 09:27. / www.sciteclibrary.com.
5. Vorsanova S.G., Ahmedova Z.A., Demidova I.A., etc. Cytogenetic characteristic of children with nephropathy from the region polluted with heavy metals. /www.dialysis.ru/magazine/2000_3/chi_neph.php