This study delves into the potential of giant mud crab shell biochar as an adsorbent for methyl violet removal in wastewater treatment. The research focuses on biochar produced at different pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More temperatures, with CSB500 (pyrolyzed at 500 °C) exhibiting promising physicochemical properties, including a surface area of 59.73 m2/g and mesopore size of 31.3 nm, facilitating efficient methyl violet removal at 3139 mg/g.

Langmuir and Redlich-Peterson isotherm models validate monolayer adsorption, while kinetics data align with pseudo-first-order and pseudo-second-order models. Intraparticle diffusion and Boyd’s models suggest both film and pore diffusion involvement. Hot water regeneration studies highlight CSB500’s superior performance at 70 °C, achieving >90 % MV removal for six regeneration cycles.

The use of giant mud crab shell biochar is seen as a low-cost, effective, and eco-friendly strategy for dye removal. Its reusability and robust adsorption capacity position it as a sustainable option for wastewater treatment. The study emphasizes the importance of addressing water pollution, particularly from dye-related contaminants, and underscores the potential of crustacean waste, such as giant mud crab shells, in creating environmentally friendly adsorbents.

Moreover, the research acknowledges the multifaceted applications of giant mud crab shell across various industries, from pharmaceuticals to electronics, showcasing its versatility and potential contributions to environmental sustainability. The integration of giant mud crab shell biochar in wastewater treatment aligns with sustainability and circular economy principles, offering a cleaner and more eco-friendly alternative that minimizes chemical consumption, reduces greenhouse gas emissions, and supports a circular economy by repurposing food industry by-products.