ADSORPTION CAPACITY OF LEAF POWDER OF FRUIT TREES AND BERRY BUSHES ACCORDING TO SPECTROPHOTOMETRY DATA

The results of the study of the adsorption of methylene blue from aqueous solutions by the powder of the leaves of fruit trees and berry bushes are presented. The adsorption capacity was determined by the method developed for activated carbon. The suitability of the spectrophotometric analysis method for determining the adsorption capacity of leaf powder was confirmed by the results of linearity and repeatability assessment. The applicability of the Langmuir, Freundlich and BET models to describe experimental adsorption isotherms of methylene blue on a powder mixture of leaves with a particle size of 0.25 mm is analyzed. By comparing the correlation coefficients, it is shown that the Langmuir and BET model describe experimental data on dye adsorption on powder better than the Freundlich model. The values of adsorption constants for the Langmuir model (KL=1.17 l/mmol) and BET (KBET=319.75 g/mmol) were obtained using the graphical method. Among the studied fruit trees, cherry leaf powder had the greatest adsorption capacity (0.532±0.017 mmol/g), among berry bushes – aronia, blackcurrant and gooseberry leaf powder (0.529±0.002; 0.472±0.011 and 0.479±0.004 mmol/g). Based on a comparative assessment of the results obtained with the value of the adsorption capacity of activated carbon (0.704 mmol/g), a conclusion was made about the suitability of the powder of the leaves of fruit trees and berry bushes for the removal of methylene blue from aqueous solutions.