Facial conjugate adsorbent for sustainable Pb(II) ion monitoring and removal from contaminated water

Abstract

The chemical ligand-based conjugate adsorbent was prepared for selective and sensitive toxic lead (Pb(II)) ions monitoring and removal from contaminated water to save water quality and human health. Both in the monitoring and removal operations, the solution pH played a vital role by the conjugate adsorbent. The data clarified that pH 3.50 was suitable for simultaneous monitoring and removal of Pb(II) ions. In the monitoring, a significant color was formed upon the addition of Pb(II) ion even in the presence of ultra-trace level. Then the solution pH, reaction time, foreign ion, and initial concentration effect were systematically measured. The conjugate adsorbent exhibited an extremely low detection limit (0.35 µg/L) to comply with the material’s applicability in real sample onsite monitoring. In the reaction time effect, color optimization and high removal efficiency was achieved by increasing the reaction time. However, the diverse foreign ions were not adversely affected in the monitoring and removal to clarify the conjugate adsorbent as sensitive and selective towards the Pb(II) ions. The conjugate adsorbent was shown highly ordered structure and was able to open high functionality for Pb(II) ion monitoring and removal. The adsorption data also revealed that the present conjugate adsorbent exhibited adsorption capacity (172.87 mg/g) and was well fitted by the Langmuir adsorption isotherm with monolayer coverage. The adsorbed Pb(II) ion was desorbed using 0.30 M HCl and then simultaneously regenerated into the initial form for several cycles use after rinsing with water. Then it is expected that the optimum protocol effectively captured the Pb(II) in a sustainable and environmentally friendly manner for the production of clean water to safeguard public health and environmental remediation.