Institute of Maritime Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung City, Taiwan.
J Environ Manage. 2020 Sep 15;270:110869. doi: 10.1016/j.jenvman.2020.110869. Epub 2020 Jun 5.
This work recovered the dredged sediment around Kaohsiung Harbor, Taiwan, for preparing lightweight aggregates (LWA), of which physicochemical properties as affected by the addition of basic-oxygen-furnace (BOF) slag and waste glass were investigated. LWA properties included water absorption, particle density, compressive strength, shrinkage, and microstructure of sintered pellets were evaluated to ensure feasibility of dredged harbor sediment reutilization technique. Results showed that adding appropriate amount of glass powders (~7%) to the mixtures of sediment and slag significantly reduced the water absorption (as low as 2.2%) of the sintered pellets and increase the compressive strength (as high as 23.1 MPa) of LWA, which were found to be controlled by open porosity and shrinkage. Excessive addition of glass (>10%) led to increase in internal pore sizes of the sintered pellets, and thus reduced the compressive strength. The alkali-silica reactivity (ASR) of the LWA was innocuous according to the ASTM C289 test. Sintering and glass addition improved the stability of heavy metal and environmental compatibility of the LWA. The recycling of waste sediment, slag, and glass for LWA production can provide an alternative for the disposal of dredge harbor sediment and has positive impact on waste reduction, which not only can reduce secondary contamination to the environment, but also can contribute to circular economy.
本研究以高雄港疏浚底泥为原料，添加转炉渣及废玻璃制备轻集料，探讨底泥添加转炉渣和废玻璃后对轻集料物理化学性能的影响。研究轻集料的吸水率、颗粒密度、抗压强度、收缩率和烧结球团的微观结构，以评估疏浚港泥再利用技术的可行性。结果表明，在底泥-转炉渣混合物中添加适量的玻璃粉（约 7%）可显著降低烧结球团的吸水率（低至 2.2%）并提高轻集料的抗压强度（高达 23.1 MPa），这主要受显气孔率和收缩率的控制。玻璃粉添加过量（>10%）会导致烧结球团内部孔径增大，从而降低抗压强度。根据 ASTM C289 测试，轻集料的碱硅酸反应（ASR）无危害性。烧结和玻璃添加可提高重金属的稳定性和轻集料的环境相容性。废弃底泥、转炉渣和废玻璃回收用于生产轻集料可为疏浚港泥的处置提供替代方案，对减少废物和促进循环经济具有积极影响，不仅可以减少对环境的二次污染，还可以节约资源。
