Start-up alternatives and performance of an UASB pilot plant treating diluted municipal wastewater at low temperature.
Different start-up procedures of an upflow anaerobic sludge bed (UASB) digester were carried out. Start-up without inoculum (experiment A) was delayed for about 120 day. The digester reached 75-85% total suspended solids (TSS) removal, 54-58% total chemical oxygen demand (TCOD) removal and 63-73% biological oxygen demand (BOD5) removal at influent concentrations of 240-340 mg TCODil-1, temperatures of 13.5-15 degrees C and hydraulic retention times (HRT) of 10-11 h. Digested sludge was used as inoculum in experiment B. After the start-up period of 75 days, digester efficiencies were 58%, 41% and 54% for TSS, TCOD and BOD5 removal, respectively, working at 169 mg TCODil-1, temperature of 14 degrees C and HRT of 11 h. The sludge bed developed and stabilised quickly when using a hydraulically adapted inoculum (experiment C), but TCOD and BOD5 removals remained low and volatile fatty acids (VFA) accumulated in the effluent.
Alvarez
J A
JA
Dept. of Química Física e Enxeñaría Química I, University of A Coruña, A Zapateira s/n, 15071 A Coruña, Galiza, Spain.
Ruiz
I
I
Gómez
M
M
Presas
J
J
Soto
M
M
D001421:Bacteria, Anaerobic / Q000502:physiology*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D002947:Cities; D003080:Cold Temperature; D005160:Facility Design and Construction; D005232:Fatty Acids, Volatile / Q000032:analysis; D005240:Feasibility Studies; D005285:Fermentation; D010865:Pilot Projects; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014872:Water Movements
D005232:Fatty Acids, Volatile; D012722:Sewage