SYNOPSIS

What is 3D printing? How Chemical Engineers can use 3D printing technology to print adsorbent for wastewater treatment. First case study is related to a robust approach of integrating 3D printing and surface grafting of chitosan is one of the emerging adsorbents for removing pollutants from wastewater, particularly dye pollutants. This study investigated and compared the effects of drying methods on silane-grafted chitosan of 3D-printed PEGDA monolithic structure using convective hot air drying, vacuum drying and freeze-drying methods. It was found that convective hot air drying of chitosan (ODC) silane-grafted monolith was more desirable than vacuum drying chitosan (VDC) and freeze drying of chitosan (FDC). To test the efficacy of methyl orange (MO) dye removal, a batch adsorption performance was tested at 50 mg/L of MO dye at optimal conditions found using response surface methodology (RSM). It was found that the maximum dye removal efficiency of ODC silane-grafted monolith is 90% with an uptake capacity, K of 12.7 mg/g. The recycle ability of all three absorbents was verified by evaluating their adsorption for five cycles and retained its performance after the second cycle. The convective hot air-drying method is better than the vacuum drying and freeze drying method as the silane-grafted chitosan monolith obtained has excellent surface properties and adsorption capability for dye removal.

Second case study is related to a robust Poly (ethylene glycol) diacrylate PEGDA - based monolithic support structures in which magnetic chitosan fluid (MCF) integrated with dispersed magnetite nanoparticles was coated on, forming a reusable adsorbent for wastewater treatment. The physical adsorption and desorption process, aided by the formation of intermolecular bridge between MCF and (3-aminopropyl) trimethoxysilane (APTMS) crosslinker, as well as exposure to alternating magnetic fields respectively, showed promise for wastewater treatment applications. Surface functionalisation, enhanced with rose petal effect-inspired novel grafting technique, possible through spray coating crosslinker between 0.25 and 2.00 bar establishes strong covalent bonds between APTMS and MCF, enhancing affinity and adhesion. The nanostructure fosters hydrogen bond formation between amino and hydroxyl groups, inducing crucial surface hydrophobicity for optimal adsorption in acidic wastewater. Experimental validation through weight loss calculation confirmed the adsorbent’s resilience to prolonged contact with synthetic methyl orange (MO) dye for 6h without leaching. Optimisation studies using response surface methodology (RSM) with central composite design (CCD) evaluated the effect of hot air drying (HAD) parameters including solvent deposition time (0.5 to 2.5h), drying temperature (50 to 80 ⁰𝐶), and drying time (1 to 5h) on adsorption performance.


BIODATA OF SPEAKER

Associate Professor Ir. Ts. Dr. Chien Hwa CHONG is Associate Professor at Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham. He currently is a Professional Engineer registered with the Board of Engineer, Professional Technologist (Chemical), International Professional Engineer (Int PE (MY)), APEC Engineer, ASEAN Engineer, Chartered Chemical Engineer, IChemE (UK) and Chartered Engineer of the Engineering Council, UK. Dr. Chong obtained the fellow of the Higher Education Academy UK in 2020. He was the former Chairman of Chemical Engineering Technical Division 2019-2021 and advisor for Chemical Engineering Technical Division 2021-2022. He served as Council member of Institution of Engineers Malaysia (IEM) 2021-2024 and Head of Delegates, Head of Panels for Accreditation Council (EAC) and Engineering Accreditation Technology Council (ETAC) visits for local and UK, Australia and China branch campuses Chemical Engineering Programme offered in Malaysia. He was the external reviewer for Newcastle University in Singapore undergraduate and postgraduate programme in 2020-2021. He has received academic awards including Vice Chancellor’s Top Cited Academician Award in 2015 at Taylor’s University, Presidential Awards of Excellence, Institution of Engineer Malaysia (IEM) from 2013 to 2016.  In 2023, he received two gold medals again in an international exhibition, was conferred a fellowship from the Institution of Engineers Malaysia and received an outstanding research supervisor award and a Vice Chancellor Medal 2023, University of Nottingham, UK. He also won an International Invention & Innovative Competition (INIIC) 2022 Award: Gold Award and Best Video Winner (Category : Higher Institution - Science, Engineering & Technology).

Further to this, he won a Gold medal in International Conference and Exposition on Inventions by Institutions of Higher Learning (PECIPTA), which is a biannual program organized by Ministry of Higher Education Malaysia together with its partner institutions of higher learning (IHL) and he won the Diamond and Gold awards in the 3rd Virtual Innovation Competition 2022 (VIC22). In total more than 872 participants from local and international organizations such as Indonesia, India, and the Philippines. Only 13 projects were selected as special Diamond awards. The special Diamond award received is under the category of TERTIARY – SCIENCE & TECHNOLOGY. In 2023, he won a Gold medal at Malaysia Invention & Innovation Expo 2023 and International virtual expo of innovation product and system design 2023, Universiti Malaysia Perlis 2023. All awards are related to the 3D-Printed PEGDA Monolith with Robust Silane-Grafted Chitosan for the Enhanced Textile Wastewater Treatment research project.