Reclamation of landfills requires solutions to many unusual issues in the field of geotechnics and environmental engineering. The aim of the paper was to present some examples of reclamation works aimed at reducing the impact of an old municipal solid waste landfill on the soil-water environment and ensuring geotechnical safety. The article discusses several technical solutions applied in shaping the landfill body and strengthening the stability of the slopes. Moreover, some methods of reducing the spread of pollutants within the landfill site were presented. The article presents an example of a landfill located in difficult hydrogeological conditions, which for many years of operation did not have any systems applied for the purpose of protection from contamination. Based on the results of monitoring and numerical modeling, a beneficial effects of reclamation works on the improvement of groundwater quality and conditions of landfill slope stability were demonstrated. It was also shown that the application of a vertical barrier and a leachate drainage system have a positive effect on the improvement of the condition of plant communities in the landfill surroundings. It was concluded that reclamation works do not essentially change the function of the landfill but reduce its negative impact on the environment, in particular by limiting the spread of pollutants into the soil-water environment, protecting the slopes from erosion, reducing dust, increasing evapotranspiration and improving landscape value.

The case study of a dismissed petrochemical plant located in Southern Italy is presented, wherein phosphoric acid production residues have to be transformed through a series of on-site treatment procedures into non-reactive stabilised wastes, which can be accepted for disposal in a non-hazardous solid waste landfill according to the regulations in force. Oedometric compression, triaxial shear, torsional ring shear and column leaching tests were carried out with the aim to determine the strength and deformability parameters of the stabilised residues, as well as to investigate the long-term mobility of water-soluble contaminants under a confining stress level that simulates the final disposal conditions. Such a characterisation of the coupled chemo-hydro-mechanical behaviour allowed the effectiveness of such treatment procedures in producing a waste stream that does not pose threats to the landfill geotechnical stability to be ascertained.

Due to certain similarities of municipal waste and soil, usually for the determination of basic parameters of physical state, laboratory and field tests which are common in geotechnical investigations are used. It is often to construct an apparatus for special purpose to perform some specific laboratory and field tests. Therefore, different values of indicators of municipal waste physical state can be found in the literature. The basic reasons should be found in different definitions and methods that researchers use during their determinations, which further complicate a comparison of obtained results. Unlike soil, determination of physical parameters of municipal waste is more complex, because of its extremely heterogeneous composition, consistency, biodegradability etc. In addition, physical properties of waste change over time, so the method of taking and selection of representative samples is problematic and has not yet been standardized. In this paper, the most common determination methods of basic parameters of municipal waste physical condition will be presented (moisture content, organic substances content, unit weight, specific gravity, porosity, grain size distribution), using standard geomechanical laboratory equipment. In addition, average values of these parameters based on literature data, as well as results obtained by testing the old municipal waste from two landfills in Serbia (closed landfill Ada Huja in Belgrade and city landfill in Novi Sad) will be presented.

The containment performance of bentonite-based barriers is known to be influenced by the semipermeable membrane behaviour of the bentonite, which arises from the electrical interactions between the clay particles and the ionic species dissolved in the pore solution. Most of the experimental research conducted to date has provided evidence of the clay membrane behaviour, the extent of which is typically quantified through the reflection coefficient, w, when the permeant (electrolyte) solution contains a monovalent or divalent salt. Under such conditions, the osmotic counter-flow of solution is controlled to a great extent by the solute exclusion, which is also referred to as the chemico-osmotic effect. However, theoretical simulations of coupled solute transport and solvent flow suggest that, when two or more cations with different diffusivities are contained in the permeant solution, the electro-osmotic effect, which stems from the condition of null electric current density, can be comparable to or even greater than the chemico-osmotic effect. The relative importance of the aforementioned contributions to multi-electrolyte systems is examined herein through the interpretation of laboratory test results from the literature pertaining to a bentonite-amended clay soil permeated with aqueous mixtures of potassium chloride (KCl) and hydrochloric acid (HCl).

Cover liners are the top layers placed when the closure of a landfill is decided. The top layers are normally subjected to the direct influence of moisture, temperature changes, and erosion. It is suggested to assess the shear strength of clay cover liners using a dynamic cone penetrometer as a quick tool for assessment. The areas indicating poor shear strength are assessed for the density and moisture influence on the compressibility and shear strength parameters. The dynamic probe was found to give reliable results for bentonite sand mixtures. Zones for moisture content were established to reflect the bilinear cone penetration and moisture content relationships and trends. The laboratory fall cone tests were conducted to verify the trends of penetration and influence of dry density in the zones of relatively dry soils within the wet of optimum side of the compaction curve. The laboratory test results were assessed and recommendations to improve the shear strength evaluation using dynamic cone penetrometer are presented.

A confined disposal facility (CDF) was built at the Ancona Harbour (Italy) to host contaminated dredged sediments. The Port Authority intended to get the chance to use the reclaimed land as a storage area. Since dredged sediments typically have very high void ratios when disposed in a CDF, their consolidation is essential to achieve proper mechanical characteristics. Consolidation of sediments by prefabricated vertical drains (PVDs) and embankment preloading is being planned. Since large strains are expected, nonlinear constitutive relations for compressibility and hydraulic conductivity are required to model consolidation processes. For this purpose, sediments were characterised by laboratory tests to determine compressibility and permeability laws, followed by field investigations (CPTUs and dissipation tests). A full scale test field has been designed to calibrate modelling and set up the operating procedures. The paper illustrates and discusses the design criteria of the test field.

In Japan, approximately 4 million tons of incineration bottom ash (IBA) from municipal solid waste (MSW) are discharged a year. Since Japan does not have enough space to bury this material in landfills, it is necessary to reuse IBA. However, since bottom ash includes toxic material, immobilization is needed for effective use. This study is focused on carbonating treatments that immobilize bottom ash by exhaust gas (EG) and carbon dioxide (CO2) generated from the Saga city incineration plant. In this incineration plant, CO2 is separated and collected from EG generated when garbage is incinerated; this is Japan's first carbon dioxide capture and utilization (CCU) plant at a waste incineration facility. The mechanical characteristics and leaching properties of carbonated IBA for use as construction materials, such as base course or embankment materials are determined in tis study using the California bearing ratio (CBR) test, cone index, and leaching tests. As a result, it was revealed that carbonated IBA can be reused as a subbase course material. Also, the leaching concentrations of heavy metals from carbonated IBA were influenced by carbonating treatment processing and its immobilization effect was higher in CO2 than in EG. It was also revealed that the concentration of lead meets the environmental quality standard values for soils set by the Japanese Ministry of the Environment.

Multiphysics of seismic analysis and reactive chemical transport analysis were conducted to evaluate the long-term environmental safety of hazardous waste landfills having a reinforced concrete structure. The structure stabilities when huge earthquakes occurred were assessed using seismic analysis. The bending moment generated in the reinforced concreate materials was converted into the crack width, and then the calculated crack width was applied as the boundary conditions of hazardous waste landfill for reactive chemical transport analysis. The results of reactive chemical transport analysis showed the long-term leaching concentration profiles from hazardous waste landfill and specified the factors affecting its environmental safety. This paper finally presents the importance of multi-barrier system consisting of stabilization/solidification techniques and artificial/natural soil sorption layer in order to minimize negative impacts of hazardous waste landfill.

Direct and indirect effects of landfill gases and interrelationships between direct and indirect climate-forcing emissions and cover soil characteristics were analyzed at 5 municipal solid landfills in California. Fluxes of 80 chemicals were quantified across daily, intermediate, and final covers using static flux chambers. Whole-site emissions were scaled up using the flux data. Direct and indirect climate-forcing emissions were estimated through application of global warming (direct), atmospheric degradation (direct), tropospheric ozone forming (indirect), stratospheric ozone depleting (indirect), and secondary aerosol forming (indirect) potentials reported for each chemical. Methane emissions accounted for 46 to 99% of the total direct climate-forcing emissions. Nitrous oxide and F-gases collectively accounted for 1 to 99% of the total direct climate-forcing emissions. Overall direct emissions accounted for 93 to nearly 100% of the total combined (direct and indirect) climate-forcing emissions. Correlations were observed: a) between direct and indirect climate-forcing emissions of greenhouse gases and water content parameters as well as void ratio and b) between direct and indirect climate-forcing emissions of NMVOCs and mass of water in a cover profile, volumetric air content, temperature, and volumetric solids content.

Solid waste management causes a significant challenge for the developing countries, especially in Vietnam. While the construction industry has enjoyed continuous development, huge amounts of construction and demolition waste (CDW) being generated and dumped illegally on the vacant areas including roadsides, streets, and canals occur frequently. The consequences of improper waste management are potential alarming. With the rising concerns of CDW management this research aims to evaluate the potential environmental impacts associated with CDW and to identify the best alternative in managing the CDW. The aim of this study is to analysis the current situation of CDW management in order to identify the environmental impacts related to CDW. This research intended to be assessing CDW recycling potential and evaluating on the economic feasibility of the utilizing of recycled materials in the future. This paper combines the planning methodology to present the final results in thematic maps that make easier to interpret them. The results of the study would play the major role in developing a sustainable system such as assessing recycling potential, choosing appropriate treatment options, or operating solid waste management system.

Considering the requirement of environment and ecosystem, permeable pavement gradually became a hot issue recently. However, the conventional permeable pavement only allowed the surface layer for drainage, while the permeable subgrade was less mentioned. In addition, the acceleration of urbanization process was accompanied by a large number of municipal solid waste (MSW) production. Among the treatment method towards MSW, incineration was widely used around the world, and resulted in a huge amount of municipal solid waste incineration (MSWI) bottom ash. Thus, the MSWI bottom ash was proposed to act as permeable subgrade material in this paper, since its low cost and eco-environmental nature. According to the test and calculated results, MSWI bottom ash presented excellent adsorption capacity towards methylene blue, around 5.44 mg/g, which was regarded as one typical organic pollutant. Through observing its microstructure and calculation based on isothermal adsorption equilibrium data, the adsorption process is mainly occurred in the form of physical adsorption. Considering above adsorption parameters, the contaminant migration and transport inside the subgrade towards surrounding environment was evaluated according to solute transport model, including influence factors like hydraulic behavior, adsorption, diffusion etc. The calculation results indicated that the adsorption capacity of MSWI bottom ash effectively retarded the diffusion of contaminant.