Chowdhury Rumpa, Al Biruni Mir Tanvir, Afia Antara, Hasan Mehedi, Islam Mohammed Russedul, Ahmed Tanvir
Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh.
Department of Civil Engineering, Military Institute of Science and Technology, Mirpur Cantonment, Dhaka 1216, Bangladesh.
Materials (Basel). 2023 Aug 13;16(16):5612. doi: 10.3390/ma16165612.
Medical waste incineration fly ash (MWIFA) contains heavy metals that are toxic by nature and pose numerous health risks. The paper deals with the suitability of MWIFA as a mineral filler in the bituminous layer as an alternative to conventional stone dust (SD) through an appropriate combination of engineering and environmental assessments. Engineering parameters, such as Marshall stability, stability loss, flow, unit weight, air voids (V), voids filled with asphalt (VFA), and voids in the mineral aggregate (VMA) of the asphalt mixtures, were evaluated with varying filler ratios, from 2% to 10%. All parameters for both fillers at optimum bitumen content satisfied the Marshall Mix Design criteria. The optimum bitumen contents of all filler ratios were within the standard limit recommended by the Bangladesh Roads and Highways Department. It was found that mixes prepared with MWIFA can resist moisture effects, making them durable in the monsoon. The mixes with 5.5% MWIFA as mineral filler performed the best, whereas 9% SD filler was required to achieve similar performance. The environmental test results show no environmental restriction on stabilizing the MWIFA into paving mixtures. The mobility of heavy metals (As, Pb, Cu, Cr, Ni, Cd, Hg, and Zn) from the asphalt-MWIFA mix was insignificant. The cumulative concentrations of heavy metals (Cd, Ni, Zn, Cu, and Pb) from long-term leaching tests were far below the Dutch regulatory limit (U1). MWIFA can be considered an eco-friendly and sustainable mineral filler for the dense bituminous pavement layer.
医疗废物焚烧飞灰（MWIFA）含有天然有毒的重金属，会带来诸多健康风险。本文通过工程评估与环境评估的适当结合，探讨了MWIFA作为沥青层矿物填料替代传统石粉（SD）的适用性。对沥青混合料的工程参数进行了评估，如马歇尔稳定度、稳定度损失、流值、单位重量、空隙率（V）、沥青填隙率（VFA）和矿料间隙率（VMA），填料比例从2%到10%不等。两种填料在最佳沥青含量下的所有参数均满足马歇尔混合料设计标准。所有填料比例的最佳沥青含量均在孟加拉国道路和公路部门推荐的标准限值内。研究发现，用MWIFA制备的混合料能够抵抗水分影响，使其在季风季节具有耐久性。以5.5%的MWIFA作为矿物填料的混合料性能最佳，而使用9%的SD填料才能达到类似性能。环境测试结果表明，将MWIFA稳定化用于铺路混合料不存在环境限制。沥青-MWIFA混合料中重金属（砷、铅、铜、铬、镍、镉、汞和锌）的迁移性微不足道。长期浸出试验中重金属（镉、镍、锌、铜和铅）的累积浓度远低于荷兰监管限值（U1）。MWIFA可被视为用于密实沥青路面层的生态友好型和可持续矿物填料。
