Baolei Liu, Shixing Zhang, Lingfeng Zhao, Cunyou Zou, Jianlong Xiu
Bio-gels are a class of functional polymeric materials with three-dimensional network structures. Their exceptional biocompatibility, biodegradability, high specific surface area, and tunable physicochemical properties make them highly promising for environmental remediation. This article systematically reviews the classification of bio-gels based on source, cross-linking mechanisms, and functional attributes. It also elaborates on their fundamental properties such as porous structure, high water absorbency, stimuli-responsiveness, and mechanical stability and examines how these properties influence their environmental remediation efficiency. This review comprehensively analyze the mechanisms and efficacy of bio-gels in adsorbing heavy metal ions, removing organic dyes, improving soil water retention, and restoring ecosystems. Special attention is given to the interactions between surface functional groups and contaminants, the role of porous structures in mass transfer, and the ecological effects within soil-plant systems. Additionally, this review explores extended applications of bio-gels in medical tissue engineering, controlled release of drugs and fertilizers, and enhanced oil recovery, highlighting their versatility as multifunctional materials. Finally, based on current progress and challenges, this review outline key future research directions. These include elucidating microscopic interaction mechanisms, developing low-cost renewable feedstocks, designing multi-stimuli-responsive structures, improving long-term stability, and establishing full life-cycle environmental safety assessments. These efforts will help advance the efficient, precise, and sustainable use of bio-gels in environmental remediation, offering innovative solutions to complex environmental problems.