Sustainable Evaluation of Using Nano Zero-Valent Iron and Activated Carbon for Real Textile Effluent Remediation

In this study, the performance of using two different adsorbents, nano-zero-valent iron (nZVI) and activated carbon (AC), was examined for the treatment of real textile effluents. The porous structure and chemical composition of the synthesized nZVI were detected via X-ray diffraction, scanning electron microscopy and EDX analysis. Batch adsorption studies were conducted to investigate the optimal operating conditions including pH, adsorbent dose, contact time and stirring rate for the removal of COD, TSS and color from real textile wastewater. At same optimal operating conditions, pH 6, dose 0.8 g/L, contact time 20 min and stirring rate 100 rpm, the experimental results showed distinctive removal efficiency by using AC reached to 78.8% for COD, 76.2% for TSS and 84% for color, while nZVI recorded relatively lower removal efficiency reached to 74.7% for COD, 72.6% for TSS and 80% for color. A comparison study between nZVI and AC was conducted to evaluate the potential of using the two sorbent materials based on technical and sustainable criteria using different multi-criteria decision-making methods: TOPSIS, AHP and SAW. The study concluded that generally AC is better than nZVI based on the established criteria and weights.