Biochar of Spent Coffee Grounds as Per Se and Impregnated with TiO2: Promising Waste-Derived Adsorbents for Balofloxacin

Abstract

Biochars (BC) of spent coffee grounds, both pristine (SCBC) and impregnated with titanium oxide (TiO2@SCBC) were exploited as environmentally friendly and economical sorbents for the fluroquinolone antibiotic balofloxacin (BALX). Surface morphology, functional moieties, and thermal stabilities of both adsorbents were scrutinized using SEM, EDS, TEM, BET, FTIR, Raman, and TG/dT analyses. BET analysis indicated that the impregnation with TiO2 has increased the surface area (50.54 m2/g) and decreased the pore size and volume. Batch adsorption experiments were completed in lights of the experimental set-up of Plackett–Burman design (PBD). Two responses were maximized; the % removal (%R) and the adsorption capacity (qe, mg/g) as a function of four variables: pH, adsorbent dosage (AD), BALX concentration ([BALX]), and contact time (CT). %R of 68.34% and 91.78% were accomplished using the pristine and TiO2@SCBC, respectively. Equilibrium isotherms indicated that Freundlich model was of a perfect fit for adsorption of BALX onto both adsorbents. Maximum adsorption capacity (qmax) of 142.55 mg/g for SCBC and 196.73 mg/g for the TiO2@SCBC. Kinetics of the adsorption process were best demonstrated using the pseudo-second order (PSO) model. The adsorption-desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 66.32% after the fifth cycles.

Integrated Approaches for Adsorption and Incorporation Testing of Green-Synthesized TiO2NPs Mediated by Seed-Priming Technology in Punica granatum L.

“…Therefore, the seeds primed with TiO 2 NPs_CE revealed an enhanced carbon (C) signal due to the imidazole ring of the caffeine polymer in addition to the more activated carbons derived during the processing of the coffee ground and the preparation of CE. The typical moieties present in the coffee ground were also identified in other studies [52,53], e.g., the aliphatic C-H stretching vibration.…”

Electrochemical Analysis of Sulfisoxazole Using Glassy Carbon Electrode (GCE) and MWCNTs/Rare Earth Oxide (CeO2 and Yb2O3) Modified-GCE Sensors

“…Controlling the variables affecting the synthetic process helps having a control over the particle size and the particle size distribution [ 32 , 33 , 34 ]. The effect of the presence of surfactants during the hydrothermal synthesis of metal oxides have been reported in literature [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. In general, surfactants are known for their ability to exert a control over the morphology and the crystal growth of inorganic nanoparticles, most likely because of the adsorption of the surfactant on the surface of the nanoparticles hindering their further growth.…”

Biochar for agronomy, animal farming, anaerobic digestion, composting, water treatment, soil remediation, construction, energy storage, and carbon sequestration: a review

“…Additionally, changes in pH can significantly affect the electrostatic interactions as measured by the zeta potential (point of zero charge) of the biochar. When the solution pH is less than the point of zero charge, this implies that the biochar surface is positively charged, which enhances the adsorption of negatively charged pollutants, and vice versa when the solution pH is greater than the point of zero charge (El-Azazy et al 2020 ; El-Azazy et al 2021a ; Kelm et al 2019 ).…”

“…As a result, one of the primary challenges inherent in this process is the appropriate selection and optimisation of process variables in order to maximise biochar yield and performance. Therefore, the operation of predictive models serves to reduce the burden on the environment, improve method greenness, and contribute to the long-term goals of sustainability and circular bioeconomy (El-Azazy et al 2020 ; El-Azazy et al 2021a ; Bhagat et al 2020 ; Hiranjit 2015 ; Hodgson et al 2016 ; Karimifard and Alavi Moghaddam 2018 ; Kostić et al 2016 ; Lakshmi et al 2021 ; Puccini et al 2017 ).…”