Bottom ash (BA) management is often implemented through its co-disposal with municipal solid waste (MSW) in landfills. However, BA co-disposal may lead to heavy metal leaching in landfills. In this study, the effect of BA co-disposal on heavy metal leaching behavior under different scenarios, specifically, MSW, low BA co-disposal (BA_L), high BA co-disposal (BA_H), and BA monofill were investigated. The heavy metal concentrations in the leachate decreased in landfills over time. The leached metals primarily included Zn, Cu, Mn, Pb, Cr, and Cd. The discharge concentration ratio of heavy metals in the leachates exhibited the following decreasing order: MSW, BA_L, BA_H, and BA. In particular, the discharge concentration ratio of Cu in the MSW, BA_L, BA_H, and BA cases ranged from 7.1×10^-3 to 8.8×10^-1 (mean=3.0×10^-1), 2.8×10^-4 to 2.0×10^-1 (mean=5.4×10^-2), 9.1×10^-5 to 3.0×10^-2 (mean=5.9×10^-3), and 4.4×10^-4 to 7.9×10^-3 (mean=1.8×10^-3), respectively. Moreover, the leaching of the heavy metals could be attributed to waste contents, properties of the heavy metals, and leachate characteristics, such as the pH, chemical oxygen demand (COD), alkalinity, and Cl^- content. The presented findings can help clarify the leaching characteristics of heavy metals in BA co-disposal landfills, thereby facilitating the optimization of practical landfills.

底灰 (BA) 管理通常通过与垃圾填埋场中的城市固体废物 (MSW) 共同处置来实施。然而，BA 的共同处置可能会导致垃圾填埋场的重金属浸出。在本研究中，研究了不同情景下 BA 协同处置对重金属浸出行为的影响，特别是 MSW、低 BA 协同处置 (BA_L)、高 BA 协同处置 (BA_H) 和 BA 单体填充。随着时间的推移，垃圾填埋场渗滤液中的重金属浓度降低。浸出的金属主要包括锌、铜、锰、铅、铬和镉。渗滤液中重金属排放浓度比呈递减顺序：MSW、BA_L、BA_H和BA。特别是生活垃圾、BA_L、BA_H和BA情况下Cu的排放浓度比在7.1×10 ^-3到8.8×10 ^{-1 之间}（平均值=3.0×10 ^-1），2.8×10 ^-4到 2.0×10 ^-1（平均值=5.4×10 ^-2），9.1×10 ^-5到 3.0×10 ^-2（平均值=5.9×10 ^-3 ) 和 4.4×10 ^-4到 7.9×10 ^-3 (平均值=1.8×10 ^-3 )。此外，重金属的浸出可归因于废物含量、重金属的性质和浸出液特性，例如pH、化学需氧量(COD)、碱度和Cl ^-含量。研究结果有助于阐明 BA 共处置垃圾填埋场中重金属的浸出特性，从而促进实际垃圾填埋场的优化。