Sheng-Yen Tsai, Chao-Kai Chang, Pei-Yu Wei, Shi-Ying Huang, Mohsen Gavahian, Shella Permatasari Santoso, Chang-Wei Hsieh
In light of industrial developments, water pollution by heavy metals as hazardous chemicals has garnered attention. Addressing the urgent need for efficient heavy metal removal from aqueous environments, this study delves into using poly-γ-glutamic acid (γ-PGA) for the bioflocculation of heavy metals. Utilizing γ-PGA variants from Bacillus subtilis with different molecular weights and salt forms (Na-bonded and Ca-bonded), the research evaluates their adsorption capacities for copper (Cu), lead (Pb), and cadmium (Cd) ions. It was found that Na-bonded γ-PGA with a high molecular weight showed the highest heavy metal adsorption (92.2–98.3%), particularly at a 0.5% concentration which exhibited the highest adsorption efficiency. Additionally, the study investigated the interaction of γ-PGA in mixed heavy metal environments, and it was discovered that Na-γ-PGA-HM at a 0.5% concentration showed a superior adsorption efficiency for Pb ions (85.4%), highlighting its selectivity as a potential effective biosorbent for wastewater treatment. This research not only enlightens the understanding of γ-PGA’s role in heavy metal remediation but also underscores its potential as a biodegradable and non-toxic alternative for environmental cleanup. The findings pave the way for further exploration into the mechanisms and kinetics of γ-PGA’s adsorption properties. © 2024 by the authors.
Department of Food Science and Biotechnology, National Chung Hsing University, South Dist., Taichung City, 402202, Taiwan; College of Ocean Food and Biological Engineering, Jimei University, No. 43 Yindou Rd., Xiamen, 361021, China; Department of Food Science, National Pingtung University of Science and Technology, Pingtung, 912301, Taiwan; Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Surabaya, 60114, Indonesia; Department of Chemical Engineering, National Taiwan University of Science and Technology, Daan Dist, Taipei, 106221, Taiwan; Department of Medical Research, China Medical University Hospital, Taichung City, 404333, Taiwan