In Switzerland, municipal solid waste incineration bottom ash is deposited in open landfills, which leads to its interaction with rainwater and thus the formation of a polluted leachate. This study attempts to provide a better understanding of the hydraulic and geochemical properties of bottom ash landfills by combining field and laboratory investigations. The results show that a bottom ash landfill can be described as a generally unsaturated body with several layers of different grain sizes. Three different water domains with variable hydraulic and geochemical properties were identified in the landfill: (1) zones of preferential flow, (2) a reservoir of mobile porewater, and (3) an immobile porewater reservoir. Preferential flow systems account for approximately 5–10 vol.%. The landfill layering is primarily responsible for the formation of various flow systems during heavy rainfall events. The domains and reservoirs provide variable volumetric contribution to the leachate, depending on precipitation rates and duration of dry periods. Sampling of leachate during heavy rainfall events revealed dilution effects for Na (− 59–61% compared to concentrations prior to the event), Ca (− 44–47%), Cl (− 57–77%), and SO₄ (− 35–47%), while pH (+ 7–8%) and concentrations of Al (+ 368–1416%), Cu (+ 7–58%), Cr (+ 29–48%), V (+ 100–118%), and Zn (+ 289%) increased significantly. The findings of this study serve as a basis for the development of a hydrogeochemical model of a bottom ash landfill, which allows better prediction of the future evolution of leachate quality.

在瑞士，城市固体废物焚烧底灰沉积在露天垃圾填埋场，导致其与雨水相互作用，从而形成受污染的渗滤液。本研究试图通过结合现场和实验室调查来更好地了解底灰填埋场的水力和地球化学特性。结果表明，底灰填埋场可以描述为具有多层不同粒度的总体不饱和体。在垃圾填埋场中确定了具有可变水力和地球化学特性的三个不同的水域：（1）优先流区，（2）移动孔隙水库，以及（3）固定孔隙水库。优先流系统大约占 5–10 vol.%。垃圾填埋场分层主要负责强降雨期间各种流动系统的形成。根据降水率和干旱期的持续时间，区域和水库对渗滤液的体积贡献是可变的。强降雨事件期间渗滤液采样显示，Na（与事件发生前的浓度相比，− 59–61%）、Ca（− 44–47%）、Cl（− 57–77%）和 SO ₄（− 35–47%)，而pH (+ 7–8%) 和 Al (+ 368–1416%)、Cu (+ 7–58%)、Cr (+ 29–48%)、V (+ 100– 118%) 和 Zn (+ 289%) 显着增加。这项研究的结果为开发底灰垃圾填埋场水文地球化学模型奠定了基础，可以更好地预测渗滤液质量的未来演变。