Synthesis, Characterization and Sorption Properties of Biochar, Chitosan and ZnO-Based Binary Composites towards a Cationic Dye

Abstract

Industrial effluents contaminated with different types of organic dyes have become a major concern to environmentalists due to the carcinogenic nature of the dyes, which are harmful to human and aquatic life. In recent years, the treatment of contaminated effluents by natural resources has been proposed as the most sustainable solution for this problem. In this work, Moringa oleifera (M. oleifera) seed-derived biochar composites, e.g., Biochar-Chitosan (BC), Biochar-ZnO (BZ), and Chitosan-ZnO (CZ) were produced and characterized. The synthesized materials were then utilized to adsorb a cationic dye, methylene blue. Spectroscopic analysis of the biochar-based composites revealed that the modification of biochar by chitosan and ZnO introduced different functional and active groups in the biochar surface. Pore development in the structure of biochar nanocomposites was visible in surface morphological images. The derived biochar was fully amorphous and increased crystallinity by the ZnO modification. The obtained surface area varied from 0.90 ± 0.00 to 14.48 ± 1.13 m2 g−1 for prepared sorbents, where BZ corresponds to the highest and BC corresponds to the lowest surface area, respectively. The basic pH (9) was the most favorable condition for sorption. The sorption reached equilibrium at 90 min. Isotherm revealed the favorability of the Langmuir model over the Freundlich and Temkin models. The highest sorption capacity (~170 mg/g) was found for BC. The BC and BZ showed a 75% increase and 16% decrease in removal due to the chitosan and ZnO modification, respectively. Response surface methodology (RSM) optimization for BC showed similar results to the analytical experiments. The characterization and experimental results prefigure the chemical functionalities as the critical parameter over the surface area for the adsorption process.

Deashed Wheat-Straw Biochar as a Potential Superabsorbent for Pesticides

“…Increase in relative intensity in the BCd sample may be related to uncovering of the surface functional OH groups due to the removal of the mineral components from BC, which facilitates the chemical binding of ionic molecules. For both biochars, absorption in the region between 2925 and 2848 cm −1 was assigned to C–H stretching vibration from the methyl and methylene groups [ 61 ]. An intense band at 1617 cm −1 is related to the vibrations of aromatic C=C and C=O groups of conjugated ketones and quinones [ 31 ].…”

Optimization of ciprofloxacin removal by response surface methodology using activated carbon from Burmese grape obtained from Vietnam

“…The lack of fit value for the model is 20.18 (0.0012% chance that the lack of fit value of the model can be significantly inappropriate due to noise in the experiment), which confirms that the model predicting the ability of ACBG to eliminate CFX is appropriate. 46,47…”

“…The lack of fit value for the model is 20.18 (0.0012% chance that the lack of fit value of the model can be significantly inappropriate due to noise in the experiment), which confirms that the model predicting the ability of ACBG to eliminate CFX is appropriate. 46,47 The optimal value region of the model is shown in Figure 10. The red area indicates the highest CFX adsorption efficiency, and the blue area indicates the lowest.…”

“…These include time, pH, concentration, and content. 46,47 The parameters of the factors are designed using the BBD model with three levels: central variable (0), low level (−1), high level (+1), and they are shown in Table 4. 61 ANOVA of the quadratic linear regression model was used to analyze the influence of the input, and output variables as well as the correlation of response functions and independent variables.…”

Promising management strategies to improve crop sustainability and to amend soil salinity

“…Its ability to adsorb and retain soil moisture and essential nutrients is mainly based on the porous nature of the amendment (Warnock et al, 2007;Zhang et al, 2014). Due to the presence of surface functional groups (acidic, i.e., carboxylic, phenolic, and lactones; basic-ketones, pyrones, and chromes) produced during pyrolysis (Roy et al, 2022), biochar retains an essential property of adsorption, and this property makes it a suitable and economical option in soil salinity amelioration through the removal and sorption of harmful organic compounds (Ali et al, 2017). The application of biochar in saline soil amelioration, in many ways, is discussed further in this section.…”