Search results for " Leachate"
showing 10 items of 16 documents
Achievement of partial nitrification under different carbon-to-nitrogen ratio and ammonia loading rate for the co-treatment of landfill leachate with…
2019
Abstract Partial nitrification (PN) is a technically and economically effective solution for the treatment of wastewater featuring low C/N ratio, allowing to achieve approximately 25% energy saving and 40% carbon source for denitrification. This study investigated the effect of different carbon to nitrogen ratio (C/N) and ammonia loading rate (ALR) on PN performances in a sequencing batch reactor (SBR) treating landfill leachate with municipal wastewater. The aim was to find an optimum range for C/N and ALR to maximize PN performances. Results demonstrated that a proper balancing between ALR and C/N is crucial to achieve high PN efficiency. The results highlighted the existence of an optimu…
Assessment of landfill leachate biodegradability and treatability by means of allochthonous and autochthonous biomasses
2020
Abstract The biodegradability and treatability of a young (3 years old) municipal landfill leachate was evaluated by means of chemical oxygen demand (COD) fractionation tests, based on respirometric techniques. The tests were performed using two different biomasses: one cultivated from the raw leachate (autochthonous biomass) and the other collected from a conventional municipal wastewater treatment plant after its acclimation to leachate (allochthonous biomass). The long term performances of the two biomasses were also studied. The results demonstrated that the amount of biodegradable COD in the leachate was strictly dependent on the biomass that was used to perform the fractionation tests…
A novel thermodynamic approach for the complexation study of toxic metal cations by a landfill leachate
2018
Landfill leachates can contaminate nearby aquifers. The hazards deriving from this contamination also depend on the chemical speciation of various contaminants. A novel approach is proposed here to face this problem from a chemical thermodynamics point of view. The complexing ability of the soluble fraction of a landfill leachate (collected from Bellolampo, Palermo, Italy) towards Pb2+, Cd2+ and Cu2+ has been investigated at T = 298.15 K in NaClaq at I = 0.1 mol dm−3. The soluble fraction of the landfill leachate was first characterized by different analytical techniques. Then, its acid–base properties were studied by ISE-H+ potentiometric titrations and modelled by the so-called diprotic-l…
Effect of single-species and mixed-species leaf leachate on bacterial communities in biofilms
2009
Dissolved organic matter in the form of leaf leachate represents an important carbon and energy source in many lotic ecosystems. In this study, we investigated utilization of mono-specific and mixed-species leaf leachate and impacts on biofilm bacterial community structure. Ceramic tiles were incubated in a Northeast Ohio stream to allow for biofilm development and then exposed in the laboratory to glucose or leachate from: sugar maple (Acer saccharum), pin oak (Quercus palustris), maple oak, American beech (Fagus grandifolia), witch hazel (Hamamelis virginiana), or beech witch hazel. Bacterial responses to these amendments were compared to un-amended controls based on fluorescent in situ h…
Assessment of the ecotoxicity of phytotreatment substrate soil as landfill cover material for in-situ leachate management
2019
Phytotreatment capping in closed landfills is a promising, cost-effective, in situ option for sustainable leachate treatment and might be synergistically coupled with energy crops to produce renewable energy (e.g.: biodiesel or bioethanol). This study proposes to use 0.30 m of soil as growing substrate for plants cultivated on the temporary cover of closed landfills. Once the leachate phytotreatment process is no longer required, 0.70 m of the same soil would be added to attain the final top cover configuration. This solution would entail saving the costs of excavation and backfilling. However, worsening of the initial soil quality due to potential contaminant transfer from the liquid to th…
Influence of the Height of Municipal Solid Waste Landfill on the Formation of Perched Leachate Zones
2015
Waste settlement as well as consolidation phenomena, which occur inside a landfill for municipal solid waste (MSW), can cause a decrease in waste permeability. This can lead to a reduction in conveyance of the leachate drainage system. It is therefore possible that a so-called perched leachate zone will form. Such a zone is constituted by an area in the body of the landfill where the leachate is temporarily trapped and is unable to infiltrate downward. This phenomenon is influenced by many factors, which include rain infiltration rate, waste moisture and composition, landfill height, and so on. The main aim of the paper is to elucidate the role played by landfill height in the formation of …
The Influence of MSW Landfill Height in the Perched Leachate Formation
2012
During the last decades, the largest part of municipal solid waste (MSW) generated world wide has been disposed of in landfills without any pre-treatment. The main environmental impacts of such landfills, containing high amounts of biodegradable organic matter, are caused by emissions of liq-uid effluents and landfill gas. With no collection and treatment, leachates from landfills pollute groundwater and soils locally. Furthermore, besides the biological processes, many physical phe-nomena occur inside the landfill body which negatively affect landfill management. Indeed, the waste settlement inside the landfill body, with a consequent increase of its density, corresponds to a proportional …
Modeling of perched leachate zone formation in municipal solid waste landfills.
2010
The paper presents a 1D mathematical model for the simulation of the percolation fluxes throughout a landfill for municipal solid waste (MSW). Specifically, the model was based on mass balance equations, that enable simulation of the formation of perched leachate zones in a landfill for MSW. The model considers the landfill divided in several layers evaluating the inflow to and outflow from each layer as well as the continuous moisture distribution. The infiltration flow was evaluated by means of the Darcy’s law for an unsaturated porous medium, while the moisture distribution evaluation has been carried out on the basis of the theory of the vertically distributed unsaturated flow. The solu…
Sequestering ability of landfill leachate towards toxic metal ions
2017
The great part of municipal solid wastes is worldwide stored in sanitary landfills. The interaction of organic and inorganic wastes with rainwater produces in the landfill a leachate of extremely variable composition. It depends on several variables such as the type of wastes, the age of landfill, the pH, the redox potential, etc [1-2]. Four are the recognized categories of pollutants in landfill leachate: inorganic macrocomponents, dissolved organic matter (DOM), heavy metals and xenobiotic organic compounds [3]. In particular, heavy metals (arsenic, cadmium, copper, lead, mercury, etc.) are usually present at concentration of few ppb and up to some ppm. A variable but consistent fraction …
CO-TREATMENT OF LANDFILL LEACHATE IN SBR SYSTEM: LAB-SCALE CASE STUDY REPORT
2015
SUMMARY: Landfill leachate represents nowadays one of the most controversial topics in the waste management cycle. A possible alternative for treating aged landfill leachate is represented by the co-treatment with municipal wastewater (MWW) that provides the necessary amount of biodegradable substances to enhance the development of bacteria metabolism. The correct tradeoff between landfill leachate and MWW represent a key factor in order to avoid inhibition of biomass activity. The paper reports the results of an experimental research carried out on two lab-scale Sequencing Batch Reactors (SBRs) fed with synthetic wastewater and landfill leachate in different percentages (SBR1 fed with 20% …