Adsorption of yttrium /zirconium bimetallic organic frameworks on organic phosphonate scale inhibitor HEDP

Abstract

A new yttrium zirconium bimetallic organic framework（YZr-MOF） adsorption material was synthesized by solvothermal method for the first time，and the structure and surface properties of adsorbents were characterized. Adsorption behavior and properties on organic phosphonate scale inhibitor 1-hydroxyethylidene-1，1-diphosphonic acid（HEDP） were investigated. Experimental results indicated that the structure of MOFs presented spherical particles of uniform size. The specific surface area of the adsorbent was 912.862 m2/g. At 298 K，the theoretical maximum adsorption capacity of YZr-MOF was 66.293 mg/g（calculated in P）. The adsorption process was fitted well with the pseudo-second-order kinetics equation and the Langmuir model. Moreover，the adsorption process was an endothermic process. The temperature rise was conducive to YZr-MOF adsorption of HEDP. In the adsorption experiments，the optimal amount of YZr-MOF was 0.2 g/L. YZr-MOF had good stability over a wide pH range and maintained a significant adsorption rate after six cycles. Combined with the relevant experiments and the characterization results of FTIR and XPS，electrostatic interaction and ligand exchange were the main adsorption mechanisms.

Keywords

• metal organic framework
• organic phosphonate scale inhibitor
• adsorption
• ligand exchange