Modeling Of the Mesophilic Digestion Process at the San Jose/Santa Clara Water Pollution Control Plant

摘要

To determine the effect of waste activated sludge (WAS) age on volatile solids reduction (VSR) inanaerobic digesters, simulations have been performed using GPS-X (version 6) simulator. Results showedthat an increase of sludge age from 1 to 12 days decreases VSR by almost a factor of 2. Results ofsimulation were compared with field data to assess potential improvements to be achieved by replacementof what was hypothesized to be inefficient mixing system. Comparison showed that the VSR observed inthe field was similar to the VSR predicted by simulation, i.e. replacement of the mixing system with a moreefficient one may not increase VSR. Extremely long digestion hydraulic detention time may explain thisunexpected result.