SORPTION OF HEAVY METALS FROM POLLUTED WATER AND THEIR MIGRATION IN THE SYSTEM SOIL‐TREE

Abstract

Large amounts of various contaminants are transported via natural processes from technogenic pollution sources to air, water, soil and natural ecosystems. Heavy metals (HM) are very hazardous substances having long‐lasting impact on ecosystems. They have complex negative impact on human health, animals, flora and fauna at watercourses and microflora of wastewater. Often concentration of HM exceeds maximal available concentration in wastewater. HM enter forests in their wet and dry forms from local or outer atmosphere sources; they are also brought from seas alongside with biogens and sea salt or washed from putrid or putrescent plants that concentrate in the soil or they are brought by wind or water together with mineral particles. Monitoring of forests determined that contaminants, i e HM inhibit energetic status of a tree and cause increase of tree sensitivity to diseases. In this paper the most commonly met HM, such as Ni, Mn, Zn, Pb, Cu and Co, are analysed. Pollution with HM can be reduced, if HM are accumulated by plants or absorbed by porous substances. Natural or synthetic sorbents due to their high sorption capacity, selectivity, the properties of cation exchangeability, a low price and affordability are used to remove HM from wastewater. We investigated activated carbon (AC) CKT and activated carbon (AC) UPA. The results of the investigation show that AC UPA cannot sorb HM and another sorbent ‐ AC CKT ‐ cannot sorb HM too. The transfer factor of HM from the soil to pine and birch trees was calculated, and the concentration of HM was determined in pine and birch wood, soil and polluted water. Samples of wood were burned, samples of soil were dried, and those of polluted water were analysed without special preparation. HM from wood and soil were extracted using a nitric acid solution. Samples of soil, wood and water were analysed with an atomic absorption spectrophotometer Buck Scientific 210VGP. It is determined that Ni and Mn are most effectively transferred from soil to both pine and birch wood, while Cu is less effective in accumulation in pine wood and Co ‐ in birch wood.