DUT-67 superadsorbent for the efficient and rapid removal of nonsteroidal anti-inflammatory drugs (NSAIDs) from water

Unmodified Dresden University of Technology Metal Organic Framework, DUT-67 (Zr) MOF is applied for the first time in the removal of nonsteroidal anti-inflammatory drugs, NSAIDs, specifically diclofenac (DCF) and salicylic acid (SA), from water. Several characterization techniques were performed for DUT-67 to confirm the structure of the MOF and to determine the textural and morphological properties, which revealed microporous polyhydral microcrystals. Thermal properties and zeta potential measurements were also assessed. A complete batch adsorption study was performed, assessing different parameters, such as the effect of pH, initial concentration, contact time, temperature, and the adsorbent dose, as well as regeneration. An excellent adsorption performance was obtained, where the maximum adsorption capacity was 484.9 mg/g for DCF at pH 7 and 129.9 mg/g at pH 3 for SA, according to Langmuir model. Efficient and rapid adsorption was achieved under a wide range of concentrations to represent various types of water effluents. Controlling mechanisms varied between electrostatic attraction, acid-base coordination, and π-π interactions. The adsorbent was well regenerated for four cycles after both DCF and SA adsorption, and the adsorption was satisfactory in saline conditions. Adsorption in binary systems of DCF and SA showed synergism in the removal percentages, in comparison to their single systems.