Adsorption Behaviour of Reactive Black Dye 5 by Magnetically Separable Nano-adsorbent

Dyes in the textile industry are the most significant source of pollutants, which cause damaging effects to people’s health. Reactive black 5 (RD5) is an anionic color that is currently used in the textile industry. This study is designed to provide the strategies to synthesize and characterize the new family of functionalized magnetite nanoparticles via a chemical co-precipitation method with polyaniline modification groups on the surface. The effect of various parameters including pH, the initial concentration of RD5, the mass of adsorbent, contact time, temperature and ionic strength has been studied. Under optimal conditions, 10 mL of RD5 solution with a concentration of 30 mg/L, 20 mg of adsorbent, pH of 7 and contact time of 10 minutes, the color was completely removed. The results also showed that adsorption followed Langmuir isotherm (R2=0.998) and the maximum adsorption capacity was 63.69 mg/g. The results of kinetic studies also showed that the RD5 removal followed the pseudo-second-order equation with the correlation coefficient of R2=0.9984. The ΔG0 was negative at all temperatures which shows that the adsorption process was spontaneous. Conforming to our results, adsorption process by designed magnetic nano-adsorbent is an efficient and affordable method for eliminating RD5 from the industry.