Kinetics of an anaerobic fluidized bed reactor using biolite inert carrier particles.

Abstract

This work investigates the startup and steady state operation of anaerobic fluidized bed reactors (AFBRs) with "Biolite" as the inert carrier material. Startup of AFBRs was performed using the maximum efficiency profile (MEP) and the maximum load profile (MLP) using sucrose based wastewater as feed. Although both loading profiles led to equally fast startup times of about 2 months, MEP resulted in more stable reactor operation during the startup period and thus should be preferred over MLP. Steady state experiments were performed using three concentrations of sucrose substrate and five hydraulic retention times (HRT). Organic removal efficiencies over 80% were obtained for volumetric loadings as high as 20 g/l/d. Total yield was determined to be 0.1g VFS/g COD removed demonstrating that low net synthesis of solids in the AFBR which is highly desirable for wastewater treatment systems. Under the experimental conditions tested, the AFBRs had an average solids retention time (SRT) of 150 days and a washout factor (f) of 0.01. Municipal landfill leachate was treated at steady state conditions; at two influent concentrations and four different loading rates. During the course of treating leachate, the biomass gradually became "mineralized" due to the precipitation of metal sulphides and carbonates. This resulted in loss of sludge activity and the need for higher pumping rates to maintain the same degree of bed expansion. (Abstract shortened by UMI.)