Optimization of the synthesis of activated carbon prepared from Sargassum (sp.) and its use for tetracycline, penicillin, caffeine and methylene blue adsorption from contaminated water

Abstract

This study was carried out to determine the optimal conditions for synthesizing activated carbon (AC) derived from invasive Sargassum (sp) for the efficient adsorption of emerging micropollutants [i.e. caffeine (Caf), tetracycline (Tc), penicillin V (Pen) and methylene blue (MB)] in wastewaster. A three factor’s Doehlert design at two levels (i.e. temperature of pyrolysis, T , mass ratio between activating agent H 3 PO 4 / Sargassum, r; and time of pyrolysis, t ) and response surface methodology were used. Responses measured for optimization were as follows: production yield, specific surface area, acid and basic groups, point of zero charge and adsorption capacities of Caf, Tc, Pen and MB. For individual systems (pollutants tested separately), optimized AC prepared with predicted parameters (i.e. T = 664 °C, r = 2 . 4 , t = 65 min), has reached adsorption capacities values of 329, 580, 150 and 222 mg g −1 for Caf, Tc, Pen and MB, respectively For the quaternary systems (all four micropollutants added simultaneously), total elimination using 200 mg L −1 of each molecule was: 39.9%, 48.9%, 39.7% and 70.8% for Caf, Tc, Pen and MB, respectively. These results open a very promising and efficient way for the valorization of Sargassum (sp) into AC for elimination of organic pollutants from polluted water. • Determine the optimal conditions for synthesis of AC derived from Sargassum (sp) . • Optimized AC were prepared at 664 °C during 65 min with 2.4 H 3 PO 4 impregnation. • Q max = 329, 223, 579, 150 mg/g for caffeine, methylene blue, tetracycline, penicillin. • Total elimination, with all molecules added simultaneously, is greater than 39.9%.