Comparison between the Predicted Fate of Organic Compounds in Landfills and the Actual Emissions

Abstract

Emissions of organic compounds from landfills depend on the fate of the compounds inside the landfills. This field study was used to investigate the fate in landfills of organic compounds having different physical, chemical, and biological characteristics. For this purpose, a pilot-scale landfill was constructed containing 540 m3 of ordinary household waste, 12 organic compounds were added at the top of the landfill, and leachate and landfill gas samples were continually collected and analyzed. The fate of each compound was theoretically estimated from literature data on the processes which significantly affect the compounds: sorption, dissociation, evaporation, and transformation. These processes could be described by the octanol/water coefficients, Kow, the acid dissociation constants, pKa, the Henry's law constants, H, and the potential of the compounds to be biologically transformed. The use of a ranking score system was suggested as a tool for interpreting the predicted fate of specific compounds caused by several simultaneous processes. A good correlation could be found between the measured emissions and the theoretically evaluated fate. It was concluded that the construction of a pilot-scale landfill is a useful method for studying simultaneous processes in landfills and that the emissions of organic compounds from landfills can be qualitatively predicted from literature data.

Atmospheric Chemistry of Fluorinated Alcohols: Reaction with Cl Atoms and OH Radicals and Atmospheric Lifetimes

“…The model requires the input of key physicochemical data for the fluorinated alcohol, which are given in Table . For F(CF 2 ) 2 CH 2 OH, the required physicochemical data appears in the literature, − limiting the necessity for assumptions concerning these to be made. The atmospheric fate of the alcohol has been assessed solely through direct input into that compartment.…”

Modelling the leaching of Pb, Cd, As, and Cr from cementitious waste using PHREEQC

“…Oxidising conditions were maintained for the acetic acid solutions (pe 4.0-default pe in PHREEQC). The municipal landfill leachate was assigned an initial reducing condition of pe −3.1 (corresponding to −183 mV at 25 • C), to lie within the range of typical landfill leachate redox potentials (−100 to −300 mV) [22]. For the acetic acid leachants, acetate was defined in the input file at concentrations of either 0.1 or 0.6 M. Input definitions for the municipal landfill leachate included 0.0092 M of Organic X and 0.16 M of carbonate ions (based on dissolved organic and inorganic carbon in the leachate), with other major cation and anion contents determined from the values given in Table 2.…”

Fluctuation of dissolved heavy metal concentrations in the leachate from anaerobic digestion of municipal solid waste in commercial scale landfill bioreactors: The effect of pH and associated mechanisms

“…Other model inputs included (1) temperature and pH, (2) an initial reducing environment (pE: 3.1),based on the redox potential of -183 mV [21], (3) total sulphur concentration, (4) inorganic carbon concentration in solution based on the temperature and CO 2 partial pressure in the landfill bioreactor, (5) selected mineralogical phases, and (6) a charge balance using chloride. Metal hydroxide, metal carbonate and metal sulphide were selected as model mineralogical complexes.…”