Canola meal‐derived activated biochar treated with NaOH and CO₂ as an effective tool for Cd removal

Abstract

BACKGROUND: This research assessed the capacity for Cd 2+ removal from water using canola meal-based adsorbents: canola meal chemically activated with 1 mol L -1 NaOH and pyrolyzed for 1 h at 500 °C (CAC) and the second product obtained with a similar process but with a second pyrolysis at 750 °C in CO 2 flow (CAC-CO 2 ). The materials were characterized by their chemical composition and thermal stability and using Fourier transform infrared spectroscopy, pH at point of zero charge (pH PZC ) and scanning electron microscopy. Hydroxyl and carboxyl are the most likely surface functional groups responsible for adsorption. RESULTS:The obtained pH PZC values were 10.83 for CAC and 9.84 for CAC-CO 2 . Both materials presented heterogeneous surfaces with many cavities, which increased their respective surface specific area 23 000-and 540 000-fold compared to canola meal biomass. Our best results were obtained using 4.0 g L −1 of adsorbent, at pH 7.0, with an equilibrium time of 40 and 60 min for CAC and CAC-CO 2 , respectively. The most likely mechanism predominantly involved in Cd adsorption is physical, according to Temkin nonlinear parameters, thermodynamics parameters and excellent recovery rates (67.8%).CONCLUSIONS: The use of canola meal as a feedstock for activated biochar production is an attractive and new possibility for producing a competitive adsorbent.

Canola meal‐derived biochar for highly efficient dye removal and the impact of compression treatment on porous structure

“…As shown in Fig. 3(a), the curve of canola meal exhibited abundant characteristic peaks at 3430 cm −1 , 2927 cm −1 and 2852 cm −1 , 1744 cm −1 and 1658 cm −1 , 1483 cm −1 and 1389 cm −1 , 1035 cm −1 corresponding to the stretching vibration of OH(NH), CH, CO, CO/H and CO groups 10 . The absorption peaks at 1744 cm −1 ,1658 cm −1 and 1544 cm −1 were attributed to the residual oil and the amide I and II of protein in canola meal, while the absorption peaks at 2927 cm −1 and 2852 cm −1 were assigned to the methyl and methylene groups of glucose unit of cellulose or on side chains of amino acids in protein 1,15 .…”

“…Scientists have passionately focused on the research development of porous biochar derived from waste biomass in energy storage and contaminants removal in recent years, owing to their specific surface area and porous structure 6‐8 However, there are few reports about porous carbon derived from canola meals as far as we are concerned. Previous studies have indicated that the adsorption capacity of canola meal‐derived biochar for dyes or heavy metal ions is significantly inferior to that of other biochar materials produced via a high‐temperature alkaline activation methods 9,10 . This is primarily due to the intricate chemical composition of canola meals.…”

“…Previous studies have indicated that the adsorption capacity of canola meal-derived biochar for dyes or heavy metal ions is significantly inferior to that of other biochar materials produced via a high-temperature alkaline activation methods. 9,10 This is primarily due to the intricate chemical composition of canola meals. Lipids and proteins were stored within separate cellular organelles, which were distributed throughout the aleurone layer of the endosperm and the cells of the embryo.…”

Chemical Modification of Teff Straw Biomass for Adsorptive Removal of Cr (VI) from Aqueous Solution: Characterization, Optimization, Kinetics, and Thermodynamic Aspects

“…The maximum Cr (VI) adsorption capacity of 3.51 mg/g was obtained at initial pH of 2.0 and an adsorbent dose of 0.6 g. The results of their adsorption study showed that the Langmuir model was found to fit better to the Freundlich model and pseudo-second order was found to fit as compared to pseudo-first-order kinetics. Gonçalves et al [42] have studied the adsorption of Pb +2 ions from canola meal using H 2 SO 4 modification. Their study revealed that the removal efficiency of 80% Pb +2 ions was obtained at 140 min contact time.…”