Bentonite was modified with cetyltrimethylammonium bromide by a simple method and was used as an adsorbent for the removal of Reactive Blue 21 dye. Reactive Blue 21 is an important dye used in the textile industry, which is very harmful for living creatures, especially humans. The response surface methodology (RSM) was used to study the effect of independent variables such as dye concentration (20, 40, 60, 80 and 100 mg/dm3), time (10, 20, 30, 40 and 50 min), initial pH (2, 4, 6, 8, 10) and modified bentonite dosage (1, 2, 3, 4 and 5 g/dm3) on Reactive Blue 21 dye removal efficiency from aqueous solutions. At the optimum conditions (modified bentonite dosage 5 g/dm3, dye concentration 61.3 mg/dm3, pH 4.78; time14.31 min), the predicted removal of Reactive Blue 21 on modified bentonite was 93.22%. In a confirmatory experiment, 92.01% dye removal has been obtained. Thus, the experimental investigation and statistical approach enabled us to model adsorption of Reactive Blue 21 on modified bentonite.
Removal of penicillin has been investigated using decaffeinated tea waste (DCTW). Decaffeination of tea waste was investigated using different methods. Results indicate that ozonation was the most effective process for removal of penicillin. Batch adsorption experiments were completed at various temperatures (20, 30, and 40°C), DCTW dosages (2, 4, 6, 8, and 10 g per 250 mL), penicillin concentrations (4, 10, and 14 mg/L), and pH (3, 7, and 10) conditions. Studies showed that adsorption reaches equilibrium within 40 min. The main factor affecting adsorption of penicillin was the solution pH, with maximum adsorption occurring at pH 3. Higher adsorbent dosages and lower penicillin concentrations also resulted in higher percentages of penicillin removal. Results show that data obeyed the pseudo-first-order kinetic and Freundlich isotherm models. This process proves that low-cost DCTW could be used as a high performance adsorbent for removing penicillin from aqueous solutions.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.