TITLE:
A Review on the Mechanism and Influencing Factors of Heavy Metal Removal by Biosorption Method
AUTHORS:
Yaowen Zhang
KEYWORDS:
Heavy Metals, Water Treatment, Biosorption, Physicochemical Modification, Biomodification
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.13 No.4,
April
2,
2025
ABSTRACT: Heavy metal pollutants have become a key research topic in the field of environmental science and engineering due to their strong ecotoxicity, significant bioconcentration and difficult degradation. Compared with traditional physical treatment technology, which has the defects of high cost, limited applicability and easily causes secondary pollution, the biosorption technology based on microbial metabolism has emerged as an essential research direction in the field of heavy metal wastewater treatment due to its advantages of strong economy, remarkable removal efficiency and ecological friendliness. In this paper, based on the integration of the previous research, we systematically summarized the effects of typical microorganisms (bacteria, fungi and algae) on Pb2+, As3+/As5+, Cd2+, Cr3+/Cr+, and Cd2+/Cr+. /Cr6+, Cu2+, Zn2+, and other heavy metal ions, focusing on their three-dimensional adsorption modes (complexation of extracellular matrix, binding of functional groups on the surface of the cell wall, and active intracellular transport) and their corresponding differences in removal efficacy. By analyzing the mechanism of microbial-heavy metal interactions (including but not limited to extracellular polymer precipitation, ion substitution reaction, ligand complexation, van der Waals force adsorption, redox transformation, inorganic microcrystalline deposition and intracellular bioaccumulation, etc.), we elucidated the influence of key factors, such as strain characteristics, initial concentration of heavy metals, contact time, coexisting ions and environmental parameters (pH, temperature, etc.), on the adsorption efficacy. The study further reveals the potential of this technology to be used in the adsorption of heavy metals. The study further revealed the technical bottlenecks faced by the technology in practical application: limited specific surface area of microorganisms, long screening period of advantageous strains, environmental sensitivity, difficult solid-liquid separation and insufficient selective adsorption. To address these challenges, innovative strategies such as surface modification (acid-base/oxidation treatment), genetic engineering regulation and immobilization technology (embedding method/carrier immobilization) are proposed to enhance microbial adsorption performance. This review systematically constructs the theoretical framework and technological pathway of microbial adsorption of heavy metals, which provides theoretical support and methodological reference for promoting the practical application of this technology in pollution control engineering.