(131b) Effective Removal of Arsenic from Water with Zirconium Metal-Organic Framework

Zirconium metal-organic framework (Zr-MOF) with particle size in micrometre order was synthesized and applied as a novel adsorbent in this work to remove arsenic contamination. The adsorbent functioned excellently under a wide pH range of 1 to 10, with the best adsorption performance at pH 2. No inhibitory effect on the adsorption process was observed in the presence of such commonly existing anions as chloride, nitrate, carbonate and sulphate. The adsorption isotherm study indicated that the maximum arsenate adsorption capacity reached as high as 303 mg/g at optimal pH 2 and 148 mg/g at neutral pH condition 7, which greatly outperform most adsorbents reported in literature. The EDX, PXRD and FTIR studies indicated that the interaction between arsenic and Zr-MOF occurred at two possible sites within the adsorbent framework, i.e., hydroxyl group and benzenedicarboxylate ligand, by which Zr-O-As coordination bonds were formed. Compared to most conventional nanoparticle sorbents, the highly porous crystalline structure of Zr-MOF provides a larger contact area and more active sites in unit space, which facilitate the diffusion and interaction of arsenic species towards the adsorbents. The excellent adsorption performance in removal of arsenic from aqueous solutions using Zr-MOF would provide new insights to the application of MOFs for water treatment, and lead to a promising advanced adsorbent in arsenic decontamination industry.