Anaerobic organic acid production of food waste in once-a-day feeding and drawing-off bioreactor.
Acidogenesis of food waste was studied in a 2-L reactor with semi-continuous mode operation (once-a-day feeding and draw-off) for maximum 65 days to examine optimal volatile acid compositions for biological nitrogen removal (BNR) and enhanced biological phosphorus removal (ENPR). Various operational parameters of hydraulic retention time (HRT), organic loading rate (ORL), pH and temperature were investigated for soluble chemical oxygen demand (SCOD), volatile fatty acid composition, nitrogen and phosphate. The yields (gTVFA/g VS) and the volumetric productivity (gTVFA/d L) increased with HRT from 0.26-0.32, 1.25-1.50 (at 4 days) to 0.36-0.39, 1.71-1.83 (at 12 days). However, the acetate fraction (%) decreased with HRT from 35.7-37.5 at 4 days to 23.5-25 at 12 days. The yields decreased with increase of organic loading from 0.34-0.37 at 5 g/L d to 0.29-0.30 at 13 g/L d and the productivity increased from 1.63-1.65 to 3.61-3.75. The yield and productivity were highest at 35 degrees C among 25, 35 and 45 degrees C. The yield and productivity at pH 5.5 and 6.0 were best and very similar to each other. The condition of 35 degrees C, pH 6.0, HRT 8 days, ORL 9 g/L d resulted in TVFA, SCOD, acetate and butyrate of 25, 39.5, 12 and 5.25 g/L, respectively.
Lim
Seong-Jin
SJ
Department of Chemical and Biomolecular Engineering, KAIST, 373-1, Daejeon 305-701, Republic of Korea.
Kim
Byoung Jin
BJ
Jeong
Chang-Moon
CM
Choi
Jin-dal-rae
JD
Ahn
Yeong Hee
YH
Chang
Ho Nam
HN
D000693:Anaerobiosis; D001421:Bacteria, Anaerobic; D019149:Bioreactors / Q000382:microbiology*; D005232:Fatty Acids, Volatile / Q000096:biosynthesis*; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000302:isolation & purification; D010100:Oxygen / Q000378:metabolism; D010758:Phosphorus / Q000302:isolation & purification; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors
D005232:Fatty Acids, Volatile; D012722:Sewage; D010758:Phosphorus; D009584:Nitrogen; D010100:Oxygen