Reliability assessment of bioreactor landfills using Monte Carlo simulation and coupled hydro-bio-mechanical model.

The performance of a bioreactor landfill is highly influenced by the simultaneous interactions of several coupled processes that occur within the landfill. In addition, the high uncertainty and spatial variability in the geotechnical properties of municipal solid waste (MSW) poses significant challenge in accurately predicting the performance of bioreactor landfills. In this study, a 2D coupled hydro-bio-mechanical (CHBM) model was employed to predict the behavior of MSW in bioreactor landfills.

Influence of dynamic coupled hydro-bio-mechanical processes on response of municipal solid waste and liner system in bioreactor landfills.

A two-dimensional (2-D) mathematical model is presented to predict the response of municipal solid waste (MSW) of conventional as well as bioreactor landfills undergoing coupled hydro-bio-mechanical processes. The newly developed and validated 2-D coupled mathematical modeling framework combines and simultaneously solves a two-phase flow model based on the unsaturated Richard's equation, a plain-strain formulation of Mohr-Coulomb mechanical model and first-order decay kinetics biodegradation model. The performance of both conventional and bioreactor landfill was investigated holistically, by evaluating the mechanical settlement, extent of waste degradation with subsequent changes in geotechnical properties, landfill slope stability, and in-plane shear behavior (shear stress-displacement) of composite liner system and final cover system.

Slope stability of bioreactor landfills during leachate injection: effects of heterogeneous and anisotropic municipal solid waste conditions.

In bioreactor landfills, leachate recirculation can significantly affect the stability of landfill slope due to generation and distribution of excessive pore fluid pressures near side slope. The current design and operation of leachate recirculation systems do not consider the effects of heterogeneous and anisotropic nature of municipal solid waste (MSW) and the increased pore gas pressures in landfilled waste caused due to leachate recirculation on the physical stability of landfill slope. In this study, a numerical two-phase flow model (landfill leachate and gas as immiscible phases) was used to investigate the effects of heterogeneous and anisotropic nature of MSW on moisture distribution and pore-water and capillary pressures and their resulting impacts on the stability of a simplified bioreactor landfill during leachate recirculation using horizontal trench system.

Study of mechanism of enhanced antibacterial activity by green synthesis of silver nanoparticles.

The extensive use of silver nanoparticles needs a synthesis process that is greener without compromising their properties. The present study describes a novel green synthesis of silver nanoparticles using Guava (Psidium guajava) leaf extract. In order to compare with the conventionally synthesized ones, we also prepared Ag-NPs by chemical reduction.

Improved critical current density of MgB2--carbon nanotubes composite.

In the present study, we report a systematic study of doping/admixing of carbon nanotubes (CNTs) in different concentrations in MgB2. The composite material corresponding to MgB2-x at.% CNTs (35 at.