Solving fecal coliform growth/reactivation in biosolids during full-scale post-digestion processes.
Fecal coliform recurrence has been observed at the City of Los Angeles Hyperion Treatment Plant during pilot-scale experiments with a designated thermophilic battery of six anaerobic digesters, while other digesters were still at a mesophilic temperature. Several lab and full-scale experiments indicated the following possible causes of the growth/reactivation of fecal coliforms in post-digestion: a) contamination of thermophilically digested biosolids with mesophilically digested biosolids; b) a large drop in the biosolids temperature between the centrifuges and silos, which could have allowed the reactivation and/or growth of fecal coliforms. These were resolved by the full plant conversion to thermophilic anaerobic digestion and design modifications of the post-digestion train.
Iranpour
R
R
City of Los Angeles Bureau of Sanitation, Hyperion Treatment Plant, 12000 Vista del Mar, Playa del Rey, CA 90293, USA. rezairanpo@aol.com
Palacios
R
R
Cox
H H J
HH
Abkian
V
V
D001421:Bacteria, Anaerobic / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D015169:Colony Count, Microbial; D004755:Enterobacteriaceae / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D015141:Los Angeles; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*
D012722:Sewage