Preferential flow in Landfill Simulating Reactors

Abstract

Uniform moisture addition/leachate recirculation is pre-requisite for consistent degradation of municipal solid waste in bioreactor landfills.  The flow conditions in the landfills need to be investigated to determine the path followed by the moisture in the landfills. The present study investigates solute transport through moisture flow in landfill simulating reactors using sodium chloride as tracer. Four plexiglass reactors of dimensions 60cm height and 17cm diameter were used as landfill simulating reactors. Municipal solid waste samples were collected from the Wariana dump site located in Jalandhar city of Punjab state, India. Two reactors were packed with municipal solid waste at two different densities and other two reactors were loaded with organic solid waste again at two different densities. Reactors were flushed with water and a pulse of tracer was applied. Inflow of water was reestablished after the tracer application. Leachate samples were collected at regular time intervals. This investigation indicated the preferential flow paths in solid waste through the interpretation of breakthrough curves (BTCs). Nature of the waste and its compaction density affected the extent of channelization in the landfill simulating reactors.