NH2-UiO-66 (Zr) modified waste wool fibers for efficient adsorption of dye from water

Abstract

Developing low-cost and stable adsorbent is urgent and attractive to remove hazardous dye from water. In this study, zirconium based metal-organic framework (NH2-UiO-66) was grown on waste wool fibers and the fabricated composite adsorbent (NH2-UiO-66/wool) was used to remove anionic dye methyl orange (MO). After characterizing the adsorbents, we determined the effect of pH and initial concentration of MO on adsorption performance. Moreover, adsorption kinetics and isotherms were conducted to reveal the adsorption mechanism. The results showed that NH2-UiO-66/wool achieved the highest adsorption capacity at natural pH with the maximum adsorption of 61.0 mg/g adsorbent, which is higher than most biomass based adsorbents. Moreover, NH2-UiO-66/wool enabled a broad range of pH (3−11) and initial concentration of MO (10–50 mg/L). Adsorption kinetics and isotherms of NH2-UiO-66/wool fitted well with pseudo-second-order model and Langmuir mode, respectively. NH2-UiO-66/wool presented 40.3 times higher of kinetics constant than that of original wool in the presence of initial MO concentration of 10 mg/L due to the positive nature of NH2-UiO-66. Ultimately, NH2-UiO-66/wool presented excellent regeneration ability with 500 mg/L NaCl solution and regeneration efficiency remained 98% after 10 cycles. Overall, this work may provide new insights into the development of MOFs/wool adsorbents for enhanced dye removal.