Effect of artificial soil compaction in landfill capping systems on anisotropy of air‐permeability

Abstract

Soil air permeability is an important parameter which governs the aeration in soils that significantly promotes the root growth of field and grassland species and leads, in turn, to higher levels of evapotranspiration. The German Landfill Directive (2009) requires a rigid or a minimal shrinking capping system that ensures a high evapotranspiration rate to decrease the infiltration rate through the underlying waste body and therefore the leachate generation. This research is focussed on the questions if compacted glacial till can ensure the required rigidity and if and how air permeability is affected by soil compaction. The objective was to compare air‐filled porosity and the direction‐dependency of air permeability of a capping soil when assuming rigid and non‐rigid conditions considering a shrinkage factor. Intact soil cores were sampled in vertical and horizontal direction in 0.05, 0.2, 0.5, and 0.8 m depths at two profiles of a mineral landfill capping system at the Rastorf landfill in Northern Germany. Desiccation experiments were carried out on differently‐compacted soils and soil shrinkage was measured with a 3D laser triangulation device, while the air permeability was estimated with an air flow meter. The results indicate that the “engineered” soil structure which was predominately platy due to a layered installation, led to a more anisotropic behaviour and therefore to higher air permeability in horizontal than in vertical direction. The compacted installation of the capping system seems to be effective and observes the statutory required more‐or‐less rigid system, otherwise, soil shrinkage would lead to vertical cracks and a more pronounced isotropic behaviour.

Designing of Wet Transformers as Artificial Soil for Flower Tree Cultivation

“…In addition, according to the activities of wet garbage transformers as new developed artificial soil it is based on the electric energy from solar cell panel with the positive attitude for reducing of carbondioxide quantities into the world atmosphere. Thus, it is friendly to our world environment in the high level (Milbrandt, A., et al, 2018;Beck-Broichsitter, S., et al, 2020), as well as reducing the chemical fertilizer and spoilage ratios of wet garbage to release carbon dioxide into the world atmosphere as one way. With this case, it is compared to the operation guideline conforming with the preparation plan in the project of greenhouse effect reduction with Thailand Voluntary Emission Reduction Program: T-VER in the future.…”

Effect of organic residues on soil properties of loamy topsoil of haplic Luvisol in Northern Germany

“…However, wheat-containing digestate (20w80b) seems to slightly improve or not deteriorating the AWC as hypothesized before. It should be noted that the increase in the air capacities indicates an increase in the volume fraction of pores available for air flow or soil aeration, but it is not identical with the accessibility of oxygen for plant roots (Reszkowska et al, 2011;Beck-Broichsitter et al, 2020a). The application of organic residues, however, significantly lowered the pore continuity at pressure heads of −60 and −300 hPa, except digestate 20w80b.…”

“…The impact of organic residues on soil chemical properties, for example, organic carbon (OC) and nutrient supply (Voelkner et al, 2015a) or wettability (Beck-Broichsitter et al, 2020b) is comprehensively analyzed, whereas a lack of information is still existing for physical properties including the plant available water capacity and air permeability. The process of soil aeration is important for the root growth and the crop production of arable soils (Zhai and Horn, 2018;Beck-Broichsitter et al, 2020a). This includes a sufficient continuity of pores and a stable pore network (Horn et al, 2014), but tilled topsoils are known for discontinuities in the pore system through mechanically induced homogenization compared to non-tilled topsoils (Lipiec et al, 2003;Dörner et al, 2012;Assis et al, 2016).…”

Simultaneous determination of wettability and shrinkage in an organic residue amended loamy topsoil

“…The volumetric water content, θ, for the prepared soil cores with 8-10 repetitions for loam and loam-residue mixtures with ρ b values of 1.45 g cm -3 each were determined by a combined pressure plate (saturated, -60, -300 hPa) and ceramic vacuum outflow method (-15000 hPa) as well as oven-dried for 24 hours at 105°C, respectively. Simultaneously, the soil volume change was determined with the 3D laser triangulation method (Beck-Broichsitter et al, 2018a, 2020Seyfarth et al, 2012). In brief, the line laser CMS 106 with λ = 660 nm (Control Micro Systems, Orlando, FL, USA) illuminates a soil core along the cylindrical surface (rotation centre at the z-axis), depending on the scan area.…”