Efficient Adsorption Removal of an Anionic Azo Dye by Lignocellulosic Waste Material and Sludge Recycling into Combustible Briquettes

Abstract

In recent years, the removal of dyes has emerged as a significant problem that attracted several researchers. The search for green and eco-friendly adsorbents has been a never-ending task in environmental protection to overcome this issue. Herein, almond shells (AS) were used as an adsorbent to remove methyl orange (MO) from aqueous solutions. The AS was characterized using several techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). Adsorption experiments were carried out under different pH, temperature, and AS particle size conditions. Kinetic and isothermal studies revealed that MO adsorption on the AS reached equilibrium at 90 min, following the pseudo-second-order (PSO) kinetic model. The Langmuir adsorption isotherm was found the suitable adsorption model for MO adsorption on AS, showing a maximum adsorption capacity of 15.63 mg/g. Thermodynamic parameters such as the change in standard enthalpy (ΔH°), the change in standard entropy (ΔS°), and the change in standard free energy (ΔG°) indicated that the MO dye adsorption process is non-spontaneous, endothermic, and physical, which was further confirmed from FTIR analysis of AS samples after adsorption. The contaminated sludge was converted into biochar by slow pyrolysis at a temperature of 400 °C for 2 h. Biochar has been exploited for the manufacture of combustible briquettes.

Fabrication and Characterization of Effective Biochar Biosorbent Derived from Agricultural Waste to Remove Cationic Dyes from Wastewater

“…Phosphoric acid and Zinc chloride are two of the most often used activating agents in chemical activation, aside from NaOH and KOH [20,21]. Therefore, many research studies have been published during the last couple of years investigating the use of biochar to adsorb dyes and in wastewater treatment processes [22][23][24][25][26][27][28][29][30][31][32][33]. CV and/or MB dyes were adsorbed from aqueous media by various types of biochar such as eucalyptus camaldulensis biochar (Ec-bio) [22], porous biochar [23], mesoporous seaweed biochar [24], castor biomass-based biochar [25], adsorbents from orange peel residues [26], biochar at different carbonization times [28], date palm fronds biochars [31], and rice husk-mediated magnetic biochar (RH-MBC) [33].…”

Residual Chlorella-Based Cellulose Nanofibers and Their Quaternization Modification and Efficient Anionic Dye Adsorption

“…The bands at 1425 cm −1 , 1372 cm −1 , and 1314 cm −1 were mainly associated with fundamental chains of cellulose [ 15 ]. The band located at 1046 cm −1 was due to the CO stretching of secondary alcohols [ 35 ]. The bands at 1110 cm −1 and 899 cm −1 were due to the presence of β-glucose ether bonds (C-O-C), which were involved with the vibration of the anhydrous pyranose ring skeleton and β-glycosidic bonds between anhydrous glucose rings in cellulose chains [ 40 ].…”

“…Additionally, its surface is enriched with hydroxyl groups, and it could act as a desirable adsorbent [ 32 ]. In the past decades, cellulose has been used as an adsorbent for various pollutants [ 33 , 34 , 35 ]; however, its application as an effective adsorbent is impeded because it lacks active functional groups [ 24 ].…”

3D Metallo-Supramolecular Polymer for Fast and Efficient Removal of Anionic Dyes from Water

“…This might be due to the increase in the mobility of the dye molecules, which could cause the internal structure of the adsorbent to inflate. Depending on their molecular size, it efficiently promoted the monolayer interactions of the dye molecules with internal pores. ,− …”