LONG TERM EFFECTS OF CYANIDE POLLUTION OF THE RIVER TISZA

摘要

It was studied in laboratory experiments whether in the presence of Cu(I) and Zn~(2+) ions cyanide ion could cause remaining pollution, which can have effect later or protracted. It was stated that cyanide ions adsorb "reversibly more than 98% either alone or in the presence of Cu(I) or Zn~(2+) ions. It was determined that swelling clay minerals, humus and Fe-oxides are responsible for adsorption of cyanide at conditions stated above. This list also describes the adsorption value. In our work the role of quartz became clear least because of the composition of samples. The easily determined Arany clay number is appropriate for the quick examination and evaluation of the first 3 components. The amount of cyanide adsorption is determined by the chemical state of Tisza water because of the weak acid character of HCN. On a place the amount of cyanide adsorption can be characterised by the Arany clay number of sediment and soil and the chemical state of Tisza water at that moment. The determination of cyanide adsorption is important, because sorption decreases the motion of cyanide to the motion of water, that is cyanide can get slower from the water bed via capillary tube of the soil to the nearby soil and to the subsoil water. According to the international literature (regarding the watershed of Tisza) our results concerning cyanide adsorption are new. Using radioindication we could clear the interaction between HCN and sediment and surrounding soil of Tisza. We think it is also important to study other metal and organic pollution that can occur in the watershed area. The swelling clay mineral-, organic material- and Fe-oxide-content of sediment should be determined all along the Hungarian part of Tisza. Similar studies of soils near the shore may be found on soil maps. From our experiences the composition of sediment and soil samples taken from the same place can be different sometimes. We think that these data could be useful in estimating other metal and heavy metal pollution. At last we think our most important statement is that the damage of similar cyanide pollution would be the smallest, if it is taken care of quick passing of polluted water and of keeping the Tisza in its summer waterbed.