Sawdusts of hardwood - oak and black locust, modified with formaldehyde and/or alkali solution, were used as adsorbents zinc ions from model water. The influence of concentration of alkali solution for modification, on zinc ions adsorption efficiency were investigated. Batch adsorption tests were conducted on ambient temperature. Langmuir and Freundlich adsorption isotherm equations were determinated for some adsorbents investigated. Good improvement of adsorption characteristics is achieved by modification of sawdust with alkali. Modification of sawdusts only with formaldehyde results with good prevention of leaching of organic substances as well as poor increase of adsorption efficiency.

The photocatalytic degradation of the insecticide fenitrothion was performed in the water solution in the presence of TiO2 by UV illumination. NMR spectrocopy showed that the decomposition of the initial substrate and all intermediates formed to the mineralization end products is completed in 66.3 hours. This fact was used to establish the possible mechanisms of the degradation process. The obtained results show that this method may have an important application in the removal of fenitrothion from water.