Abstract

Two carbon composite materials were prepared by mixing avocado biochar and methyl polysiloxane (MK). Firstly, MK was dissolved in ethanol, and then the biochar was added at different times. In sample 1 (R-1), the time of adding biochar was immediately after dissolving MK in ethanol, and in sample 2 (R-2), after 48 h of MK dissolved in ethanol. The samples were characterized by nitrogen adsorption/desorption measurements obtaining specific surface areas (S-BET) of 115 m(2) g(-1) (R-1) and 580 m(2) g(-1) (R-2). The adsorbents were further characterized using scanning electron microscopy, FTIR and Raman spectroscopy, adsorption of vapors of n-heptane and water, thermal analysis, Bohem titration, pHpzc, and C H N elemental analysis. R-1 and R-2 adsorbents were employed as adsorbents to remove the antibiotic ciprofloxacin from the waters. The t(1/2) and t(0.95) based on the interpolation of Avrami fractional-order were 20.52 and 246.4 min (R-1) and 14.00 and 157.6 min (R-2), respectively. Maximum adsorption capacities (Q(max)) based on the Liu isotherm were 10.77 (R-1) and 63.80 mg g(-1) (R-2) for ciprofloxacin. The thermodynamic studies showed a spontaneous and exothermic process for both samples, and the value of Delta H degrees is compatible with physical adsorption.

Keywords

Methyl polysiloxane and biochar composite; Hydrophobic surface; Pharmaceutical adsorption; Adsorption thermodynamics; Synthetic effluents

Published in

Environmental Science and Pollution Research
2022, volume: 29, number: 49, pages: 74823-74840
Publisher: SPRINGER HEIDELBERG

Authors' information