Dr. Zarko is a Professor at the Maritime Faculty, University of Dubrovnik, CROATIA. Dr. Zarko spent several years as a field engineer and Marine engineer. He is Establishing a cruise management company from the beginning til full certification (Document of Compliance, ISO 9001, establishing technical dep; purchasing dep; HR dep). Managed planned maintenance system of the ships, implemented planned maintenance system -AMOS, organized shore support, purchased certifications from flag state and classification society. Planning and supervising dry docking. Managing vendors and services. Planning, organizing, and supervising refit and rebuilding of ship interiors, new cabins, restaurants, and other public spaces on the cruise ships. Chief Engineer of Cruise Ships. Dr. Zarko has authored over 50 journal articles and conference papers in high-quality engineering and scientific journals such as the NAŠE MORE, Promet-Traffic & Transportation, and Transactions on Maritime Science. Dr. Zarko is a member and a certified engineer of the Croatian Chamber of Engineers of Transport and Transportation Technology - a professional class of marine engineers and traffic engineers on inland waterways, a Junior Editor of the international scientific journal for the sea and seafaring Naše more; and of the Journal of Environmental Science and Engineering Technology. A member of the examination committee at the Ministry of Maritime Affairs of Transport and Infrastructure - Harbour Master's Office in Dubrovnik for taking state professional examinations of a ship's engineer, Chief engineer, and ship's electro-technical officer, He is also actively involved in the international exchange of teaching staff of the Erasmus+ program.

Dr.Moon is a tenured professor in the Department of Environmental Engineering at Chosun University in Gwangju, Republic of Korea. He also serves as an associate editor for the Springer journal Environmental Geochemistry and Health. He received both his M.S. and Ph.D. in Environmental Engineering from Stevens Institute of Technology in Hoboken, New Jersey, USA. His research focuses primarily on the remediation of arsenic- and heavy metal-contaminated soils and solid wastes; the characterization of metal-contaminated soils and solid media; the fate and transport of heavy metals in soils; and the remediation of chromite ore processing residue (COPR). Dr. Moon is particularly recognized for his expertise in the stabilization/solidification (S/S) of heavy metal-contaminated soils and solid wastes. With more than 25 years of research experience, he has conducted extensive research on S/S processes for contaminated soils, solid wastes, and dredged materials. He has authored more than 140 peer-reviewed journal articles in the fields of soil remediation and solid waste treatment.

Speech title "Simultaneous Stabilization of Arsenic and Lead in Contaminated Soil Using a Composite Amendment of Fishery By-Product-Derived Partially Calcined Oyster Shell and Biochar"

Abstract-In the Republic of Korea, the enactment of the Act on the Promotion of Recycling of Fishery By-products has established a legislative framework for promoting the recycling of shell waste as a substitute for industrial limestone. However, conventional in situ stabilization/solidification (S/S) using quicklime (CaO) derived from limestone is associated with substantial CO₂emissions during high-temperature calcination and may adversely affect soil health by excessively increasing soil pH. Therefore, the development of low-carbon amendments that support the circular use of fishery by-products while minimizing adverse effects on soil ecosystems is needed. In this study, discarded oyster shells were converted into partially calcined oyster shells (PCOS) and combined with rice husk biochar (RHB) to stabilize soil co-contaminated with arsenic (As) and lead (Pb). This approach was designed to address the potential limitation of pristine biochar, which may promote As mobilization under alkaline conditions. PCOS, calcined at 750 °C for 2 h, and RHB, pyrolyzed at 750 °C for 2 h, were mixed at mass ratios of 1:0.5, 1:1, and 1:2. The resulting amendments were applied to the contaminated soil at rates of 5 and 10 wt%. Following moist curing for 1 week at a moisture content of 35 wt%, the environmental availability of As and Pb was evaluated using 0.1 M HCl extraction. Increasing the PCOS mixing ratio and amendment application rate consistently increased soil pH from 8.37 to 9.34 and improved the stabilization performance. Among the tested treatments, the 10 wt% RHB–PCOS amendment with a mixing ratio of 1:2 exhibited the highest stabilization efficiency, reducing the HCl-extractable concentrations of As and Pb by 37.3% and 43.4%, respectively. These results indicate that PCOS derived from fishery by-products can supply Ca²⁺ and moderate the increase in soil alkalinity, thereby mitigating biochar-associated As mobilization while maintaining effective Pb immobilization. The combined use of PCOS and RHB provides a promising strategy for the valorization of marine waste and the development of low-carbon remediation technologies for As/Pb co-contaminated soils.

Dr.Li has been committed for an extended period to conducting seismic research on low-reinforcement concrete gravity piers, exploring intelligent compaction techniques for subgrade, and investigating the influence of water content on unsaturated soil. In the field of seismic research, Mr.Li has proposed novel arrangements of longitudinal reinforcement of gravity railway bridge pier, which has been verified by shaking table tests. In the field of intelligent compaction, Mr.Li has proposed 3 fields coupling model to research the influence of water content in the subgrade compaction. Additionally, Mr.Li has been involved in four projects funded by the National Natural Science Foundation of China (NSFC) and published four high-level papers as the sole first author.