earticle

영어

Anthropogenic activities led to the discharge of heavy metals into aquatic systems, which are eventually deposited in sediment. Physical disturbances and environmental changes can trigger the release of these heavy metals from sediment creating potential risks to both environment and human health. Biochar has been recognized as an excellent adsorbent for restoring heavy metal-contaminated sediment. In this study, we developed two rice husk biochar (RBC) composite pellets using hydroxyapatite (HAP), and magnesium oxide (MgO), as an additive. As formed biochar composites are called HAP@RBC-P and MgO@RBC-P. The physicochemical properties of the fabricated composites were evaluated by multiple characterization techniques. The composites HAP@RBC-P and MgO@RBC-P exhibited better adsorption performance for Pb(II), Cd(II), and Zn(II) compared to RBC. The efficiency of the composites in controlling the release of heavy metals from sediment was evaluated by mixing them with the sediment. After 28 days of cover, both HAP@RBC-P and MgO@RBC-P effectively inhibited the release of Pb(II), Cd(II), and Zn(II) from sediment to overlying water, with inhibition efficiencies ranging from 80.4% to 93.65%, 57.52% to 95.2%, and 46.55% to 84.0% for HAP@RBC-P, and 50.0% to 81.4%, 70.6% to 88.6%, and 67.1% to 88.2% for MgO@RBC-P. Both biochar composite pellets exhibited high inhibition efficiencies for the release of heavy metals from the sediment composite mix. The practical applicability of these composites was assessed through a toxicity test on sediment-dwelling organisms (Lumbriculus variegatus). After a 28-day experiment, the survival rate of the Lumbriculus variegates was over 90% for both types of biochar composite pellets. indicating that the biochar composite pellet was an environmentally friendly biochar material.