Hydrodynamics of a modified up-flow anaerobic sludge blanket reactor treating organic fraction of municipal solids waste

Abstract

AbstractThe hydrodynamic of modified up-flow anaerobic sludge blanket (UASB) treating organic fraction of municipal solids wastes (OFMSW) was investigated using tracer test experiments and residence time distribution (RTD) based models. The modified UASB digester employing the up-flow reactor concept was composed of the sludge bed, localized at the bottom of the reactor, a buffer zone above the sludge bed, a section with the OFMSW, and an upper section with a solid–liquid–gas separator. The solid-state section with the OFMSW allows the separation of hydrolytic and methanogenic phases, reducing the acidification of the reactor. The hydraulic flow transports the faster biodegradable fraction from the packing section to the sludge bed, favoring the methane productivity. Residence time distribution curves were analyzed by three tracer test models (axial dispersion model ADM, tanks in series model TIS and a multiple parameter model MPM). The MPM was successfully fitted to the experimental data.