EFFECT OF DIFFERENT CALCINATION TEMPERATURES DURING THE MANUFACTURING OF FISHBONE-BASED ADSORBENT ON THE ADSORPTION CAPACITY OF THE ADSORBENT

Abstract

In Japan, soil and groundwater contamination by harmful substances such as heavy metals and radioactive substances remains a persistent issue. In the treatment methods for removing such harmful substances, there is a lack of solutions that balance high treatment capacity with low cost, and they are not always environmentally friendly. On the other hand, economic growth has led to increased waste emissions, but the disposal capacity of existing sites is decreasing year by year due to the difficulty of securing new final disposal sites. Since Goal 12 of the SDGs calls for a drastic reduction of waste generated in the production process by controlling and recycling it, the recycling of waste has been actively promoted in recent years. However, the recycling rate of food waste is low, especially fish residues, which are mostly used as feed or fertilizer, and have not been recycled beneficially. Therefore, this study aims not only to utilize fish bones as an adsorbent material but also to enhance the functionality and versatility of fishbone-derived adsorbents to adsorb a wide variety of harmful substances more efficiently and effectively. Three patterns of fishbone-based adsorbents with different manufacturing methods are tested for zinc (Zn), copper (Cu), cadmium (Cd), mercury (Hg), and strontium (Sr) with and without initial pH adjustment by immersion tests. The results show that some adsorbent types show high adsorption rates for all substances except Hg, with or without initial pH adjustment, but suggest for Hg a relationship between adsorption capacity of adsorbents and pH value in the solution.