Shaha, Bishow Nath

Leachate clogging in the Leachate Collection System (LCS) due to chemical precipitations and biofilms produced by microbial activities is a common phenomenon in any Municipal Solid Waste (MSW) landfill. This study focuses on quantifying the factors that impact the micro-environment of leachate; and microbial activities that help the precipitates to form and attach to the LCS. It also evaluates the performance of operational changes that have been implemented or the potential alternatives and recommends the possible measures to reduce the severity of clogging. A field scale side-by-side pipe network, and several laboratory setups were used in this study. Calcite is identified to be the predominant phase present in the precipitates using XRD/XRF analysis which, concur with the previous studies. Microbial growth and activities enhance the precipitation of CaCO3 in LCS. Clogging in LCS pipes can be controlled if not eliminated by continuous monitoring along with frequent cleaning with physiochemical processes.

Calcium carbonate precipitation and formation of clog particles inside the leachate
collection pipe can cause catastrophic failures in landfill operation. This study focuses on
quantifying the effectiveness of electronic scale control to reduce the clog formation within
the pipe network. A field scale model (40ft × 20ft) was constructed, featuring side-by-side
flow of electronically treated and untreated composite leachate. Data obtained in the first
phase of this study indicate that electronic scale control system does not have any
statistically significant effect on water quality parameters. The second phase of this study
identified calcite (CaCO3) to be the predominant phase present in the precipitates using
XRD/XRF diffraction pattern analyzed through a search match calculation program
(MATCH! Version 3.2.0) which concur with the previous studies. Furthermore, Rietveld
refinement using FullProf Suite confirms that there were no differences between the treated
and untreated precipitate based on the phases identified in the respective samples.