Water Science and Technology (Jan 2023)

Adsorptive removal of pharmaceutically active compounds from multicomponent system using Azadirachta indica induced zinc oxide nanoparticles: analysis of competitive and cooperative adsorption

  • Nayanathara O. Sanjeev,
  • Manjunath Singanodi Vallabha,
  • Aswathy E Valsan

DOI
https://doi.org/10.2166/wst.2022.428
Journal volume & issue
Vol. 87, no. 1
pp. 284 – 303

Abstract

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In this research, zinc oxide (ZnO) nanoparticles synthesized using neem leaf (Azadirachta indica) extract were used as an adsorbent for removing two widely used pharmaceutical compounds acetaminophen (AMP) and sulfadiazine (SDZ). The synthesized ZnO nanoparticles were characterized using SEM-EDS, FTIR, TEM, BET, and XRD analysis. The synthesized ZnO nanoparticles were found to be in the size range of 10 nm with a surface area of 48.551 m2/g. The adsorptive performance of ZnO nanoparticles in both mono-component (MoS) and multi-component system (MuS) was investigated under various operational parameters viz. contact time, temperature, pH, concentration of pharmaceutical compound and ZnO nanoparticles dose. It was observed that the maximum adsorption capacity of ZnO nanoparticles was 7.87 mg/g and 7.77 mg/g for AMP and SDZ, respectively, under the optimum conditions of 7 pH and 2 g/L adsorbent dosage. The experimental data best-fitted with the pseudo-second-order model and Langmuir model, indicating monolayer chemisorption. Further investigation on removal of AMP and SDZ from multicomponent system was modelled using a Langmuir competitive model. The desorption study has shown 25.28% and 22.4% removal of AMP and SDZ from the surface of ZnO nanoparticles. In general, green synthesized ZnO nanoparticles can be utilized effectively as adsorbent for removal of pharmaceutically active compounds from wastewater. HIGHLIGHTS Zinc oxide nanoparticles were synthesized from Azadirachta indica leaf extract.; Removal of pharmaceutically active compounds sulfadiazine and acetaminophen using ZnO nanoparticles was investigated in a mono-component and multi-component system.; An adsorption study in a multi-component system was performed using Langmuir's competitive model and nature of adsorption was studied.; Recyclability of the adsorbent was studied.;

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