Search results for "Leachate"
showing 10 items of 67 documents
Molecular composition of dissolved organic matter from a wetland plant (Juncus effusus) after photochemical and microbial decomposition (1.25 yr): Co…
2013
We hypothesized that microbial and photochemical processing of dissolved organic matter (DOM) determines its molecular formula composition in aquatic systems to a greater degree than does the original source of the DOM. To test this hypothesis, we exposed DOM from a leachate of a wetland plant (Juncus effusus) to solar radiation or incubated it in the dark for 1.25 yr. Analysis of the extracted DOM of the leachates via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) identified 2800 molecular formulae. Of the formulae in the initial DOM, 11% were lost during microbial decomposition in the dark and 54% under solar radiation. Solar radiation also produced a large number…
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…
Metakaolin geopolymer characterization and application for ammonium removal from model solutions and landfill leachate
2016
Abstract Geopolymers are aluminosilicate compounds that are amorphous analogues of zeolites, and thus possess similar cation-exchange properties. Geopolymers have been successfully applied to remove toxic metals and organic dyes from aqueous solutions. In this study, geopolymer was synthesized from metakaolin and applied to remove ammonium (NH 4 + ) from model solutions and landfill leachate. Geopolymerization increased the ammonium removal capacity, surface area and average pore width and changed the chemical structure of metakaolin. The maximum NH 4 + removal capacity of the geopolymer was 21.07 mg g − 1 which was 46% higher than the capacity of the reference clinoptilolite–heulandite zeo…
Biostimulation proved to be the most efficient method in the comparison of in situ soil remediation treatments after a simulated oil spill accident
2016
The use of in situ techniques in soil remediation is still rare in Finland and most other European countries due to the uncertainty of the effectiveness of the techniques especially in cold regions and also due to their potential side effects on the environment. In this study, we compared the biostimulation, chemical oxidation, and natural attenuation treatments in natural conditions and pilot scale during a 16-month experiment. A real fuel spill accident was used as a model for experiment setup and soil contamination. We found that biostimulation significantly decreased the contaminant leachate into the water, including also the non-aqueous phase liquid (NAPL). The total NAPL leachate was …
Selective recovery of phosphorus as AlPO4 from silicon-free CFB-derived fly ash leachate
2018
The prospect of phosphorus (P) recovery from siliceous fly ash was investigated. The phosphorus content in the pristine fly ash was 1.21%. Obtaining pure phosphorus products from fly ash is very challenging because of high concentration of other elements, silicon (Si) at 17.3% being the major contaminant. The fly ash was fractionated with sieve size of 125 μm to concentrate the phosphorus in the small-size fraction, which also facilitated the removal of 78% of silica (Si) in the solid phase. The fractionated fly ash was treated with 8 M HCl in order to remove 98% of Si by aging (5 h) of leachate until precipitation of Si-gel, and a phosphorus-rich solution is obtained. Iron (Fe) is also con…
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…
Preliminary investigation into temporal variation of volcanic ash adherent water-soluble components at Stromboli volcano during 2004-2009 eruptive ac…
2009
A change in the chemical compositions of volcanic gases is one of the noticeable phenomena that frequently occurs prior to an eruption. Tephra in plumes can absorb and thereby rapidly deposit volatiles including sulphur, halogen and metal species. These may then be leached (e.g. by rainfall), potentially releasing heavy loads into soils and water bodies. Their analysis is a suitable supplement for remote monitoring of volcanic gases from inaccessible volcanoes. Freshly fallen ashes of the eruptive activity from 2004 to 2009 at Stromboli volcano were sampled, leached and analysed for major and trace elements. This study is aimed at determining the causes of the compositional variations of th…
Leachate analyses of volcanic ashes from Stromboli volcano: A proxy for the volcanic gas plume composition?
2011
[1] Many volcanoes show a change in chemical composition of the gas phase prior to periods of eruptive activity. Fine-grained tephra erupted from active vents and transported through volcanic plumes can adsorb, and therefore rapidly scavenge, volatile elements such as sulfur, halogens, and metal species in the form of soluble salts adhering to ash surfaces. Analysis of such water-soluble surface materials is a suitable supplement for remote monitoring of volcanic gases at inaccessible volcanoes. In this work, ash samples of the 2004 to 2009 eruptive activity of Stromboli volcano were sampled, leached, and analyzed for major and trace elements. Data analysis and interpretation was focused on…
Characterization of automotive shredder residues before and five years after landfill disposal
2015
The paper illustrates the results of an extensive analytical characterization study of automotive shredder residues (ASR), also known as "fluff". The analyses concerned material fractions and their content, with special reference to heavy metals (e.g. Cd, Cr, Hg, Pb, Cu) and arsenic. Elution tests on the original materials were also conducted. Moreover, chemical concentrations of ASR samples after about five years' landfill residence was assessed, in order to verify possible changes resulting from both in-situ leaching and organic matter degradation phenomena. Results show that lead seems to be the most critical element in view of possible ASR acceptance in non-hazardous waste landfills bec…