Anaerobic attached film expanded bed reactor for the treatment of dilute organic wastes

Publisher Website
Google Scholar
Abstract
The anaerobic attached film expanded bed reactor (AAFEB) has been found to be effective for the treatment of low strength soluble organic wastes anaerobically, at reduced temperatures, short retention times, and high organic loading rates. The process consists of inert particles, approximately 500 microns in apparent diameter, packed in a cylindrical column which expand slightly with the upward flow of liquid through the column. The AAFEB permits the maintenance of high solids retention times (SRT) values with low hydraulic retention times (HRT) values. Three reactors fed a soluble synthetic waste consisting of glucose and nutrient salts at concentrations ranging from 50 to 600 mg/1 COD were monitored over a period of nine months of start up and six months of operation. The effects of temperature, influent substrate concentration, and hydraulic flow rate on process efficiency were measured. Process efficiency was evaluated in terms of soluble COD removal and other parameters. In addition an organic carbon mass balance was evaluated to verify the experimental results. Biofilm thickness and biomass concentration were also measured. This study presents an analysis of the key process variables which affect AAFEB operation and presents two simplified first order equations relating the process efficiency to the netmore » specific growth rate of the film and specific substrate utilization. The high effectiveness of this process is believed to be due to the large surface area to volume ratio created by the inert support media which enabled a large active mass of attached microorganisms to remain in the reactor at high liquid flow rates. Microbial mass concentrations exceeding 30 g/l were common in thisreactor. The rate limiting step in the overall process was the biochemical reactions and not mass transfer. A preliminary energy consumption comparison was made between the AAFEB and conventional aerobic treatment processes. « less

This publication has 0 references indexed in Scilit: