Wang Qian, Ko Jae Hac, Liu Feng, Xu Qiyong
School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China.
Department of Environmental Engineering, College of Ocean Sciences, Jeju National University, Jeju Special Self-Governing Province 63243, Republic of Korea.
J Hazard Mater. 2021 Aug 15;416:126042. doi: 10.1016/j.jhazmat.2021.126042. Epub 2021 May 7.
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 to 8.8 × 10 (mean = 3.0 ×10), 2.8 × 10 to 2.0 × 10 (mean = 5.4 ×10), 9.1 × 10 to 3.0 × 10 (mean = 5.9 ×10), and 4.4 × 10 to 7.9 × 10 (mean = 1.8 ×10), 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）管理通常通过将其与城市固体废物（MSW）共同处置在垃圾填埋场中实现。然而，底灰共同处置可能导致垃圾填埋场中的重金属浸出。在本研究中，研究了在不同情景下，即城市固体废物、低底灰共同处置（BA_L）、高底灰共同处置（BA_H）和底灰单填埋情况下，底灰共同处置对重金属浸出行为的影响。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。渗滤液中重金属的排放浓度比呈现以下递减顺序：城市固体废物、BA_L、BA_H和底灰。特别是，城市固体废物、BA_L、BA_H和底灰情况下铜的排放浓度比分别为7.1×10至8.8×10（平均值=3.0×10）、2.8×10至2.0×10（平均值=5.4×10）、9.1×10至3.0×10（平均值=5.9×10）和4.4×10至7.9×10（平均值=1.8×10）。此外，重金属的浸出可归因于废物含量、重金属性质以及渗滤液特性，如pH值、化学需氧量（COD）、碱度和氯含量。所呈现的研究结果有助于阐明底灰共同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。
