Effect of ph value and adsorbent concentration on the effectiveness of adsorption onto chitin and chitosan

The study was aimed at determining the effectiveness of reactive dye RB5 removal in the adsorption process onto chitin and chitosan as affected by the quantity of an adsorbent and pH value of the solution. The experiment was conducted at two concentrations of a sorbent, i.e. 1 and 5 mg d.m./dm3 and at three values of the reaction, i.e. pH 3.0, pH 5.0, and pH 9.0. The kinetics of RB5 sorption onto chitin and chitosan was described with the use of Langmuir model. In the case of both adsorbents examined, the highest adsorption capacity was achieved at pH 3.0 and adsorbent concentration of 1 g d.m./dm3. Increasing pH value up to pH 5.0 and 9.0 and adsorbent concentration in the sample from 1 to 5 g d.m./dm3 caused a decrease in the quantity of dye absorbed.