Citation: Fernandez, R.M.D.; Estrada, R.J.R.; Tomon, T.R.B.; Dingcong, R.G., Jr.; Amparado, R.F., Jr.; Capangpangan, R.Y.; Malaluan, R.M.; Dumancas, G.G.; Lubguban, A.A.; Alguno, A.C.; et al. Experimental Design and Breakthrough Curve Modeling of Fixed-Bed Columns Utilizing a Novel 3D Coconut-Based Polyurethane-Activated Carbon Composite Adsorbent for Lead Sequestration. Sustainability 2023, 15, 14344. https://doi.org/10.3390/ su151914344 Academic Editor: Agostina Chiavola Received: 2 September 2023 Revised: 25 September 2023 Accepted: 27 September 2023 Published: 28 September 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). sustainability Article Experimental Design and Breakthrough Curve Modeling of Fixed-Bed Columns Utilizing a Novel 3D Coconut-Based Polyurethane-Activated Carbon Composite Adsorbent for Lead Sequestration Rubie Mae D. Fernandez 1,2 , Renz John R. Estrada 1 , Tomas Ralph B. Tomon 1,2 , Roger G. Dingcong, Jr. 1 , Ruben F. Amparado, Jr. 2 , Rey Y. Capangpangan 3 , Roberto M. Malaluan 1,4 , Gerard G. Dumancas 5 , Alona A. Lubguban 6 , Arnold C. Alguno 1,7 , Hernando P. Bacosa 1,2 and Arnold A. Lubguban 1,4, * 1 Center for Sustainable Polymers, MSU-Iligan Institute of Technology, Iligan City 9200, Philippines; rubiemae.fernandez@g.msuiit.edu.ph (R.M.D.F.); renzjohn.estrada@g.msuiit.edu.ph (R.J.R.E.); tomasralph.tomon@g.msuiit.edu.ph (T.R.B.T.); rogerjr.dingcong@g.msuiit.edu.ph (R.G.D.J.); roberto.malaluan@g.msuiit.edu.ph (R.M.M.); arnold.alguno@g.msuiit.edu.ph (A.C.A.); hernando.bacosa@g.msuiit.edu.ph (H.P.B.) 2 Environmental Science Graduate Program, Department of Biological Sciences, College of Science and Mathematics, MSU-Iligan Institute of Technology, Iligan City 9200, Philippines; ruben.amparado@g.msuiit.edu.ph 3 Department of Physical Sciences and Mathematics, College of Marine and Allied Sciences, Mindanao State University at Naawan, Naawan 9023, Philippines; rey.capangpangan@msunaawan.edu.ph 4 Department of Chemical Engineering and Technology, MSU-Iligan Institute of Technology, Iligan City 9200, Philippines 5 Department of Chemistry, The University of Scranton, Scranton, PA 18510, USA; gerard.dumancas@scranton.edu 6 Department of Mathematics, Statistics, and Computer Studies, Rural High School, University of the Philippines, Paciano Rizal, Bay 4033, Philippines; alonalubguban@yahoo.com 7 Department of Physics, College of Science and Mathematics, MSU-Iligan Institute of Technology, Iligan City 9200, Philippines * Correspondence: arnold.lubguban@g.msuiit.edu.ph Abstract: This study presents a novel polyurethane-activated carbon composite (PACC) as an effective and sustainable adsorbent for treating lead-ion-contaminated waters. The PACC was characterized using Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer, Emmett, and Teller (BET) surface area analyzer, X-ray Diffrac- tion (XRD), and Thermogravimetric Analyzer (TGA) to evaluate its physicochemical and thermal properties. Furthermore, the PACC was employed in an experimental column adsorption setup to investigate its adsorption performance and to develop a dynamic method suitable for industrial implementation. Parameters such as bed height (50, 100, 150 mm), flow rate (4, 6, 8 mL min -1 ), pH (2, 4, 6), and initial metal-ion concentrations (10, 50, 100 mg L -1 ) were examined. The exper- imental data exhibited strong agreement with the Thomas and Yoon–Nelson models (R 2 ≥ 0.96), indicating efficient adsorption mechanisms. Remarkably, the used adsorbent has the potential for facile regeneration without substantial loss in capacity. The PACC demonstrated excellent adsorption performance for lead ions in aqueous solutions in a fixed-bed column system. Thus, the novel PACC material holds the potential for scalable application in industrial settings to address water pollution challenges, especially in regions with uncontrolled effluent discharge. Keywords: polyurethane foam; activated carbon; adsorption; lead; heavy metals 1. Introduction Serious concerns have been raised regarding the environmental pollution caused by heavy metals and their detrimental effects on both human well-being and ecological sys- Sustainability 2023, 15, 14344. https://doi.org/10.3390/su151914344 https://www.mdpi.com/journal/sustainability