Study on the removal of Acid Black 1 dye from aqueous solution using eco-friendly synthesized zero-valent iron nanoparticles

Acid Black 1, a commonly used industrial dye, presents significant environmental and health risks due to its carcinogenic properties and persistence in aquatic ecosystems. A sustainable approach for the removal of Acid Black 1 from aqueous solutions using green-synthesized zero-valent iron nanoparticles (nZVI) was investigated. The synthesized nanoparticles were characterized using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Dye removal was monitored through UV-Vis spectrophotometry at 618 nm. Key parameters such as pH, adsorbent dose, initial dye concentration, and contact time were optimized to enhance removal efficiency. Maximum removal (96.3 %) was achieved at a pH of 3, a dosage of 1 g/L nZVI, an initial dye concentration of 50 mg/L, and a contact time of 60 min. Adsorption isotherm analysis indicated that the Freundlich model provided the best fit, suggesting multilayer adsorption on a heterogeneous surface. Kinetic analysis followed pseudo-second-order (PSO) behavior, implying that chemisorption was the rate-limiting step. The maximum adsorption capacity, calculated using the Langmuir model, was 76.34 mg/g. The findings support the potential of nZVI as an effective and sustainable solution for dye-contaminated wastewater treatment, advancing green remediation technologies.