Biochar from Fique Bagasse for Remotion of Caffeine and Diclofenac from Aqueous Solution

Abstract

Caffeine and diclofenac are molecules with high human intake, and both belong to the ‘emergent’ class of contaminants. These compounds have been found at different concentrations in many sources of water worldwide and have several negative impacts on aquatic life systems; that is why the search for new alternatives for their removal from aqueous media is of transcendental importance. In this sense, adsorption processes are an option to attack this problem and for this reason, biochar could be a good alternative. In this regard, were prepared six different biochar from fique bagasse (FB), a useless agroindustry by-product from fique processing. The six biochar preparations were characterized through several physicochemical procedures, while for the adsorption processes, pH, adsorption time and concentration of caffeine and diclofenac were evaluated. Results showed that the biochar obtained by pyrolysis at 850 °C and residence time of 3 h, labeled as FB850-3, was the material with the highest adsorbent capacity with values of 40.2 mg g−1 and 5.40 mg g−1 for caffeine and diclofenac, respectively. It was also shown that the experimental data from FB850-3 fitted very well the Redlich–Peterson isotherm model and followed a pseudo-first and pseudo-second-order kinetic for caffeine and diclofenac, respectively.

Adsorption of Diclofenac and Its UV Phototransformation Products in an Aqueous Solution on PVDF: A Molecular Modeling Study

“…Recent modeling and experimental results for diclofenac adsorption, for example, adsorption on modified or pristine graphene, on alginate/carbon-based films or hyper-cross-linked polymer exhibit a similar range of binding affinity between generally 10–14 k B T and are therefore very comparable to the findings of this study. Furthermore, the binding affinities compare well to the values obtained by recently developed active carbon materials and biochars. − Thus, from the point of view of free energy, the binding affinities should be sufficient to investigate the design of filter materials using PVDF.…”

Study on electrical double layer nanostructure on zeolitic materials’ surface in the presence of impurities of different nature

“…The hydrogen bonds between the -COO − (present in both PAA and DCF molecules) and -NH groups of diclofenac and zeolite hydroxyl groups can be formed. Moreover, hydrophobic interactions of the π-π electron donor-acceptor type can also occur between the aromatic rings of drug molecules and carbon structures on the composite surface (Correa-Navarro et al 2020;Szewczuk-Karpisz et al 2021). The obtained results suggest that the most probable mechanism of DCF adsorption includes the presence of unbound negative groups in the by-surface layer (which has an impact on the observed surface charge reduction) and direct binding of molecules takes place through the hydrogen bridges and hydrophobic interactions (in the case of composite materials containing carbon).…”

Management of hazardous fly-ash energy waste in the adsorptive removal of diclofenac by the use of synthetic zeolitic materials

“…In the case of Na-X(C) composite, the maximum adsorbed amount is higher and equal to about 11 mg/g due to the presence of additional hydrophobic interactions. The π-π electron donor–acceptor interactions can also occur between aromatic rings of drug molecules and carbon structures on the composite surface (Correa-Navarro et al 2020 ; Szewczuk-Karpisz et al 2021 ). These interactions seems to be more pronounced for the DCF molecules than those of hydrophilic character (i.e., hydrogen bonds).…”