Fills (Earthwork)

Nuisance odors from landfills have more impact than just being an annoyance to nearby residents. With an ever-increasing population, a larger number of communities are located in closer proximity to landfills than ever before. This has brought along with it, more regular conflicts with landfill authorities surrounding the issue of odors, resulting in complaints, lawsuits, fines, and even re-siting operations. The absence of an objective method of quantifying nuisance odors makes the task of creating regulations and setting standards even more complicated. The current research focuses on a method to objectively quantify landfill odors. The human odorant binding protein 2A (hOBPIIa) can be produced using published recombinant gene technology and can be used as a biosensor to quantify odorants through spectrofluorometric measurements. The current work is a continuation of the previous work by Rahman (2020). In this work, the spent biosensor after it reacts with an odorant is shown to be regenerated by applying additional fluorophore following La Chateliers’ principle, so that the same batch of protein can be used to run multiple experiments with odorants. An important part of the work miniaturized the earlier version of the experimental setup and incorporates a much more efficient flow-through system. This setup is capable of collecting real-time readings, increasing the overall accuracy and shortening the duration of each set of the experiment. The current work also explores the response of the biosensor with an expanded group of pure odorants, including hydrogen sulfide, ammonia, toluene, formaldehyde, tert-butyl mercaptan, and methyl mercaptan as well as their mixtures, thus expanding the list of odorants tested under this principle. The results show that the protein shows a concentration-dependent response differing on the hydrophobicity of the target compound.

A numerical investigation was conducted to evaluate the geotechnical safety and slope
stability of Municipal Solid Waste (MSW) landfills, considering the effects of
geosynthetic reinforcements, biodegradation of the waste, and associated changes in
material properties, and extreme wind force simulating hurricane conditions. Three
different landfill slopes, 1:1, 1:2, and 1:3 having the height of 122m and width of 2134m,
were analyzed using Limit Equilibrium Method (SLOPE/W) and Finite Element
Modeling (ANSYS). Techniques developed in this study were used to analyze a case
history involving a geogrid reinforced mixed landfill expansion located in Austria. It was
found that few years after construction of the landfill, there is a significant decrease in the
FS due to biodegradation. Extreme wind loading was also found to cause a substantial
loss in the FS. The geosynthetic reinforcement increased the slope stability and
approximately compensated for the damaging effects of biodegradation and wind
loading.

Modem technology has led to a new generation of landfill liner systems that are
highly efficient at intercepting and removing leachate. Many of the modem liner systems
are so effective that little or no leakage occurs through the liner systems. What leakage
may occur is so minimal that, although it can be theoretically predicted, it cannot be
measured, i.e., the resulting groundwater concentrations are well beneath minimum
detection levels of available monitoring well technology. In addition to being highly
effective, some modem liner systems are constructed with two liners separated by a
drainage medium which detects and removes any leakage through the top liner.
These significant improvements in liner system technology have led many landfill
designers, operators, and regulators to question the necessity for current monitoring well
practices. Currently, landfills are required to have a large number of monitoring wells,
and the associated large installation, sampling, and testing costs are inevitably reflected
in higher tipping fees or higher taxes. In either case, the costs are borne by the public.
If the number and frequency of sampling of monitoring wells could be reduced,
significant cost savings could be realized, and the money saved could perhaps be better
spent elsewhere.
This thesis reports the results of research conducted at eleven landfills constructed
with modem landfill liner systems to determine the actual and probable efficacy of the
role o: monitoring wells, and conducts a cost-saving analysis to evaluate whether funds
would have been better spent elsewhere.