Mechanochemical Degradation of Caffeine and Diclofenac Using Biochar of Fique Bagasse in the Presence of Al: Monitoring by Mass Spectrometry.

Much research has been carried out to remove emerging contaminants using diverse materials. Furthermore, studies related to pollutant degradation have increased over the past decade. Mechanochemical degradation can successfully decompose molecules that are persistent in the environment. In this study, the biochar of fique bagasse with mixtures SiO2, Al, Al2O3, and Al-Al2O3 was treated with a mechanochemical technique using a planetary ball mill to investigate the degradation of caffeine and diclofenac. These tests resulted in the transformation of caffeine and diclofenac due to the use of Al employing mechanochemistry. In fact, through the use of liquid chromatography coupled with mass spectrometry, eight and six subproducts were identified for caffeine and diclofenac, respectively. Additionally, analysis of the molecules proposed for caffeine and diclofenac transformation suggested hydroxylation, demethylation, decarboxylation, oxidation reactions, and cleavage of the C-C and C-N bonds in the pollutants studied. The formation of these transformation products could be possible by reductant oxygen species generated from the molecular oxygen in the presence of aluminum and the energy delivered for ball milling. The results obtained show the potential application in the environmental management of mechanochemical treatment in the elimination of emerging contaminants caffeine and diclofenac.

Competitive Adsorption of Caffeine and Diclofenac Sodium onto Biochars Derived from Fique Bagasse: An Immersion Calorimetry Study.

Pharmaceuticals, including caffeine (CFN) and diclofenac sodium (DCF), are a group of emerging pollutants which have the capacity to prompt harmful effects in flora and fauna, even at relatively low concentrations. Additionally, CFN has been determined as one of the most ubiquitous active compounds in the natural environment, whereas DCF is a widely used nonsteroidal anti-inflammatory drug that has been detected in environmental sources around the world. Conversely, the fique is a plant of the Agavaceae family and of the Fucraea genus.Two native species are cultivated in Colombia, Furcraea cabuya and Furcrae macrophylla, in order to extract their fiber, but in this process a lot of waste is produced. In this study, with the fique residues, thermochemical treatments were carried out and 5 biochar samples were obtained, which were calorimetrically characterized and used to investigate their behavior in competitive adsorption of DCF and CFN. The results of the calorimetric studies show that the biochar prepared from fique bagasse have different porous and chemical characteristics, which is related to the different treatments that were used at the time of their preparation. In addition, it was established that the results of the adsorbate-adsorbent interactions determined by calorimetry allow correlation of the adsorption processes of the molecules under study (CFN and DCF). The results show that the NaOH fique biochar (FB850-3Na) presents the highest adsorption capacity in both simple and competitive tests.

Determination of gibberellic acid and abscisic acid in (Zea mays L.) (ICA-V305) seeds germinated using dynamic sonication assisted solvent extraction and maceration.

Phytohormones are molecules responsible for growth, development, and metabolism regulation in plants. Gibberellic acid (GA3) and abscisic acid (ABA) are the main phytohormones involved in seed germination. Notably, it should be a highlight that GA3 induces germination, whereas ABA inhibits it. For this reason, it is important to calculate the concentration of these two phytohormones during seeds germination. Firstly, the maize seeds (MS) were germinated and samples of these were taken at different imbibition times, after that, methanol extracts were obtained using two methods of dynamic solvent extraction assisted by sonication (DSASE) and a traditional extraction method (maceration); finally, to estimate the concentration of GA3 and ABA a high performance liquid chromatographic method was used. The results of this study showed that the three extraction methods used, allowed quantifying GA3 and ABA during the maize germination time studied. However, of the two extraction methods employed, DSASE was the best technique because higher concentrations of GA3 and ABA were found. Therefore, it is important to continue using this green chemistry methodology for these and other analyses.•The extraction protocol developed was based on dynamic sonication-assisted solvent extraction.•The chromatographic method used allowed the simultaneous determination of two phytohormones with different physicochemical properties in maize seeds.•This methodology offers good sensitivity, linearity, precision, reproducibility and suitable detection and quantification limits.

Enthalpies of Immersion in Caffeine and Glyphosate Aqueous Solutions of SBA-15 and Amino-Functionalized SBA-15.

Mesostructured silica SBA-15 and amino-functionalized silica SBA-15-NH2 were synthesized, and then, characterization, adsorption capacity, and immersion enthalpies in caffeine and glyphosate on SBA-15 and SBA-15-NH2 were evaluated. The enthalpy parameter was determined using a local construction Tian-type heat conduction calorimeter. Calorimetric studies in caffeine solutions exhibit negative enthalpy values; exothermic process characteristics for SBA-15 were between -13.90 and -194.06 J g-1 and those for SBA-15-NH2 were between -7.22 and -60.34 J g-1, and the adsorption capacity of caffeine was better in SBA-15 than that in SBA-15-NH2. In contrast, the enthalpies of immersion in glyphosate solutions were -5.06 to -56.2 J g-1 and the immersion of SBA-15-NH2 in each solution generated enthalpy values of -9.06 to -41.2 J g-1, but the adsorption capacity of glyphosate was better in the amino-functionalized SBA-15. The results show that functionalization of SBA-15 produced differences in physicochemical characteristics of solids, since energy and affinity for the calorimetric liquids are related to the surface properties of solids as well as the chemical nature of the target molecule, immersion enthalpy, was different.

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

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.

Dataset for effect of pH on caffeine and diclofenac adsorption from aqueous solution onto fique bagasse biochars.

Products of common use such as caffeine and diclofenac have been detected in surface water and groundwater, these molecules even at low concentrations have serious negative effects on animals and the environment, so they are becoming emerging contaminants. To remove pollutants from aqueous systems diverse adsorbents have been used, however materials obtained from agrochemical waste are a good alternative. This dataset present the adsorption of caffeine and diclofenac onto six fique bagasse biochars at different pH's, in addition information about textural, morphological and chemical properties of six samples of fique bagasse biochar using TGA, SEM, FTIR, PZC and Boehm's titration are provided.