Frontier review of key reduction technologies and resource utilization of waste during the seaweed gel production process

In the production of seaweed gel (agar and carrageenan), significant amounts of waste lye and solid waste residue are generated, which contain a high concentration of organic components and perlite. The utilization rate of seaweed is low, and improper disposal of these wastes can lead to environmental pollution. Traditional waste treatment methods, such as neutralization, electrolysis, and calcination, consume large amounts of energy and are often ineffective in recovering organic substances and perlite efficiently. Emerging technologies, including electrodialysis combined with membrane concentration and the integration of enzymatic and chemical methods, offer promising approaches for the effective recycling and reuse of organic materials. However, the efficiency of recycling waste lye and waste residue is influenced by the charge release mechanisms during electrodialysis and the specific actions of enzymes. To further investigate the charge release mechanisms in the electrodialysis process for waste lye recovery, techniques such as trace-charge analysis, charge diffusion modeling, and scanning electron microscopy (SEM) may be employed. Additionally, microcalorimetry and thermodynamic models can be utilized to examine the energy changes of organic substances when subjected to specific enzymes during waste residue treatment. This study reviews the current state of waste treatment methodologies and corresponding technologies in the production of seaweed gel, providing a feasible research framework. It aims to establish a theoretical and technical foundation for reducing emissions of waste lye and residue while enhancing the efficient utilization of seaweed resources.