earticle

영어

International environmental organizations predicted that the indiscriminate development of deep-sea mineral resources would have a serious impact on the marine environment. However, for countries that depend on imports of mineral resources, such as Korea (Rep. of), it is essential to develop deep-sea mineral resources. Therefore, in Korea (Rep. of), research of on-site/ex-situ treatment technologies that can minimize the impact of deep-sea mining tailings on the marine environment is being actively conducted. Therefore, in this research, the chemical washing treatment efficiency of cadmium (Cd), a harmful heavy metal, in the deep-sea mining tailings was confirmed by comparatively evaluating the two extractants. By comparing aluminum sulfate (AS) with ethylenediaminetetraacetic acid (EDTA), a traditional extractant, the environmental and economic feasibility were compared to confirm the applicability as an eco-friendly extractant. In this experiment, 2% sample was prepared by mixing deionized water and manganese nodules (20 ~ 63 μm) collected from the Clarion-Clipperton Fracture Zone (CCFZ). AS (0.3, 0.5, 1%) and EDTA (0.03, 0.05, 0.1 M) prepared at each concentrations and were added to the 2% manganese nodules sample and stirred for 16 elapsed times (5 m ~ 168 h). As the concentration of AS increased, the extraction concentration of Cd increased by an average of about 4.9 times. On the other hand, EDTA increased about 2.7 times. As the elapsed time increased, the extraction concentration by AS increased by about 3.0 times, and increased by about 8.4 times by EDTA on average. Compared to EDTA, AS showed higher Cd removal efficiency as the concentration increased and even within a short elapsed time. As a result of the research, it was evaluated that it is very suitable to use AS as an extractant of harmful heavy metals in deep-sea mining tailings when comprehensively considering removal efficiency, economic and environmental feasibility. The results of this research will be usefully applied to process design and optimization as basic data presented prior to the development of remediation technologies in the future.