Polymer-Based Nano-Adsorbent for the Removal of Lead Ions: Kinetics Studies and Optimization by Response Surface Methodology

• Published in: Separations 2022-11, Vol.9 (11), p.356
• Main Authors: Birniwa, Abdullahi Haruna, Kehili, Sana, Ali, Mujahid, Musa, Haruna, Ali, Umar, Kutty, Shamsul Rahman Mohamed, Jagaba, Ahmad Hussaini, Abdullahi, Shehu Sa’ad, Tag-Eldin, Elsayed Mohamed, Mahmud, Habibun Nabi Muhammad Ekramul
• Format: Article
• Language: English
• Subjects: adsorbent; Adsorbents; Adsorption; Ammonium peroxodisulfate; Aqueous solutions; Chelation; Chemical properties; Conducting polymers; Creeks & streams; Emission analysis; Extraction (Chemistry); Field emission microscopy; Fourier transforms; Heavy metals; Infrared analysis; Ion adsorption; Lead; lead ion; Mathematical optimization; Methods; nanoadsorbent; Nanoparticles; Nitrogen atoms; Optimization; Oxidizing agents; Polyethyleneimine; Polymers; polypyrrole-polyethyleneimine; Polypyrroles; Response surface methodology; Spectrum analysis; Surface chemistry; Thermodynamic properties; Water treatment
• ISSN: 2297-8739; 2297-8739
• DOI: 10.3390/separations9110356

This work successfully created a polypyrrole-polyethyleneimine (PPy-PEI) nano adsorbent for the elimination of the lead ion Pb2+ from an aqueous solution. An efficient conducting polymer-based adsorbent called as was created using ammonium persulfate (NH4)2S2O8 as an oxidant (PPy-PEI). The PEI hyper-branched polymer with terminal amino groups was added to the PPy adsorbent to offer heavy metals more effective chelating sites. Pb2+ removal from aqueous solution using polyethyleneimine micro adsorbent was successfully accomplished using a batch equilibrium technique (PPy-PEI). The generated water-insoluble polymer nanoadsorbent had enough nitrogen atoms; therefore, an effort was made to link PEI, a water-soluble PPy, with PPy, a conjugated polymer, for lead ion adsorption from an aqueous solution. The generated PPy-PEI nanoadsorbents were discovered to have average particle sizes of 18–34 nm and a Brunauer-Emmet-Teller surface area of 17 m2/g, respectively. The thermal behavior of the composites was investigated using thermo gravimetric and differential scanning calorimetric methods. The lead ion adsorption efficacy of pure polypyrrole was found to be 38%; however, a batch equilibrium technique employing nanoadsorbent revealed with the maximum adsorption capacity of 75.60 mg g−1. At pH 10 and 30 min of contact time at 50 °C, 0.2 g of adsorption was shown to be the ideal dosage. X-ray diffraction analysis, energy-dispersive ray spectroscopy, and Fourier transform infrared ray spectrum support the lead ion adsorption by PPy-PEI nanoadsorbents. The cauli-like structure was visible using field emission scanning electron microscopy. Studying the thermodynamic showed that the adsorption was endothermic as illustrated from the positive value of value of ΔH° is 1.439 kJ/mol which indicates that the uptake of Pb2+ onto nanoadsorbent PPy-PEI could be attributed to a physical adsorption process. According to the values of ΔG°, the adsorption process was spontaneous at all selected temperatures. The positive value of ΔS° value (43.52 j/mol) suggested an increase in the randomness at the solid/solution interface during the adsorption process. The adsorption data meet the pseudo-second-order kinetic model and suited the Langumuir isothermal model effectively.