One-pot solvothermal synthesis of Zr-based MOFs with enhanced adsorption capacity for Cu2+ ions removal

Abstract

Heavy metal copper (Cu2+) ions contamination through the discharge of industrial effluent has caused serious environmental issues globally. As a result, the removal of Cu2+ ions from water bodies are of prime importance for human health and environmental protection. In the present study, the adsorption behaviour of zirconium (Zr)-based metal organic framework (MOF-801) prepared by solvothermal method in the removal of copper ion (Cu2+) from aqueous solution was studied. The results obtained from the batch mode adsorption studies revealed that at an initial Cu2+ concentration of 10 ​mg/L, contact time of 180 ​min and adsorbent dosage of 10 ​mg, the removal efficiency and equilibrium adsorption capacity of Cu2+ from the process were 97.80% and 9.78 ​mg/g, respectively. The influence of MOF-801 on the adsorption of Cu2+ ions was studied by Langmuir and Freundlich adsorption isotherm models. The graph was found to fit well with the Freundlich isotherm, and the MOF-801's maximal multilayer adsorption capacity was determined to be 16.58 ​mg/g. A kinetic study showed that Cu2+ removal was carried out in 180 ​min with a behaviour of pseudo-second-order kinetic model and in general, the majority of metal adsorption occurred within the first 30 ​min. After four cycles of adsorption-regeneration, a reusability test using adsorbent revealed a decline in adsorption removal effectiveness of less than 11%. The MOF-801 was shown to be effective in the removal of Cu2+ from wastewater treatment.