TY - JOUR
T1 - Investigating mixed biosolids and cardboard for methylene blue adsorption
T2 - Activation, adsorption modelling and thermodynamics
AU - Zuhara, Shifa
AU - Pradhan, Snigdhendubala
AU - McKay, Gordon
N1 - Publisher Copyright:
© 2023 The Authors
PY - 2023/5/15
Y1 - 2023/5/15
N2 - Ongoing global population boom has led to the rise in waste and related research on increasing its economic value. In such an attempt, this study aims to activate gas-to-liquids (GTL) derived biosolids (BS) and cardboard (CB) and mixed samples (50:50) using potassium carbonate to produce three activated carbons (ACs): KBS, KCB and KM respectively. The characterization of the samples revealed surface areas of 156, 515, and 527 m2/g for KBS, KCB, and KM, respectively based on Brunauer-Emmett-Teller (BET) analysis, with increased porosity and metal content after activation evident from the Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) results, as well as the presence of magnetite in the KBS and KM samples apparent from the X-ray powder diffraction (XRD) results. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) results indicate increased C-O-C stretches and O-H bonds after activation of the samples. The ACs were used for methylene blue (MB) removal process which is a rapid for all three samples, reaching equilibrium after 9 h, and optimal at neutral pH and maximum at the highest temperature, 40 degrees C. The MB adsorption capacity was highest for KM (191.07 mg/g), followed by the KCB and KBS samples. Isotherm modelling of the samples showed best fits for KBS, KCB and KM as Langmuir-Freundlich (LF), Langmuir and Toth models respectively. On the contrary, kinetic modelling using contact time study data for all samples exhibited best fits by the Diffusion-chemisorption (DC) model. Finally, the thermodynamic calculations of the mixed sample disclosed the adsorption process to be exothermic and spontaneous, with potential mechanisms being electrostatic attraction, ion exchange, pi-pi interactions, and hydrogen bonding. Multiple cycles of KM regener-ation was also achieved with good adsorption capacities. Future work will explore other activation methods and examine the magnetic properties of KBS and KM for real water treatment.
AB - Ongoing global population boom has led to the rise in waste and related research on increasing its economic value. In such an attempt, this study aims to activate gas-to-liquids (GTL) derived biosolids (BS) and cardboard (CB) and mixed samples (50:50) using potassium carbonate to produce three activated carbons (ACs): KBS, KCB and KM respectively. The characterization of the samples revealed surface areas of 156, 515, and 527 m2/g for KBS, KCB, and KM, respectively based on Brunauer-Emmett-Teller (BET) analysis, with increased porosity and metal content after activation evident from the Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) results, as well as the presence of magnetite in the KBS and KM samples apparent from the X-ray powder diffraction (XRD) results. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) results indicate increased C-O-C stretches and O-H bonds after activation of the samples. The ACs were used for methylene blue (MB) removal process which is a rapid for all three samples, reaching equilibrium after 9 h, and optimal at neutral pH and maximum at the highest temperature, 40 degrees C. The MB adsorption capacity was highest for KM (191.07 mg/g), followed by the KCB and KBS samples. Isotherm modelling of the samples showed best fits for KBS, KCB and KM as Langmuir-Freundlich (LF), Langmuir and Toth models respectively. On the contrary, kinetic modelling using contact time study data for all samples exhibited best fits by the Diffusion-chemisorption (DC) model. Finally, the thermodynamic calculations of the mixed sample disclosed the adsorption process to be exothermic and spontaneous, with potential mechanisms being electrostatic attraction, ion exchange, pi-pi interactions, and hydrogen bonding. Multiple cycles of KM regener-ation was also achieved with good adsorption capacities. Future work will explore other activation methods and examine the magnetic properties of KBS and KM for real water treatment.
KW - Activation
KW - Adsorption
KW - Mechanism
KW - Mixing
KW - Modelling
KW - Thermodynamics
KW - Wastes
UR - https://www.scopus.com/pages/publications/85149206493
U2 - 10.1016/j.envres.2023.115534
DO - 10.1016/j.envres.2023.115534
M3 - Article
C2 - 36841521
AN - SCOPUS:85149206493
SN - 0013-9351
VL - 225
JO - Environmental Research
JF - Environmental Research
M1 - 115534
ER -