Efficient decontamination of textile effluents by using activated carbon derived from pine-cones and pine-needle forestry wastes: Synthesis, modeling and adsorption evaluation

In this study, pine-cone and pine-needle forestry wastes were used to produce activated carbons for the purification of dye contaminated textile effluents. The characterization of the adsorbents conducted through SEM (Scanning Electron Microscopy), N 2 porosimetry and FTIR (Fourier Transform Infrared Spectroscopy) before and after adsorption to provide insights on the adsorption mechanism. For PCAC5 S BET was 1305 m 2 /g, while for PNAC5 was 743.9 m 2 /g. FTIR confirmed the successful binding of textile wastewater through various mechanisms. Preliminary adsorption experiments performed for the removal of Methylene Violet (MV), Reactive Black 5 (RB5) and Reactive Red 120 (RR120) in single- and multi-component solutions. Optimal removal occurred at pH 3 for anionic dyes (RB5: 99.6% PCAC5, 98.2% PNAC5; RR120: 70.2% PCAC5, 94.8% PNAC5) and at pH 9 for MV (99.9% PCAC5, 99.5% PNAC5). The maximum adsorption capacities were 1198, 287 and 70.7 mg/L for MV, RB5 and RR120 removal, respectively. Kinetics followed pseudo-second order (PSO) kinetic model, suggesting that chemisorption was governing adsorption. Multi-component dye mixtures studies revealed the synergistic effect occurring between cationic and anionic species. Regeneration studies conducted for four consecutive cycles. Experiments with real textile wastewater demonstrated that a single-step adsorption approach can enhance the removal efficiency of multi-component contaminated solutions and reduce total dissolved solids (TDS) by 77% on average compared to the samples received after industrial chemical treatment. All the above suggest that pine-waste activated carbons can enhance water quality, decrease secondary environmental pollution and reduce the overall cost of wastewater treatment through a single-step green and sustainable approach. • Sustainable activated carbons were produced from pine-cones and pine-needles forestry waste for textile wastewater treatment. • High adsorption capacities were achieved for cationic and anionic dyes in single- and multi-component systems. • Binary dye mixtures showed synergistic adsorption between cationic and anionic species. • Real textile wastewater treatment confirmed the effectiveness of pine-waste activated carbons.