Effective combination of microfiltration and intermittent ozonation for high permeation flux and VFAs recovery from coagulated raw sludge.
This research was conducted to investigate the effect of intermittent ozonation on permeation flux recovery and production for soluble organic materials in a membrane-coupled anaerobic VFAs fermenter (MCAVF) system. Flux recovery ratio exceeded 80% with 22.2 gO3 l-1 of ozone injection and then showed nearly 95% with 43 gO3 l-1 in batch experiment. Under the same ozone concentration, extending contact time was more effective than increasing bubbling dose rate for flux recovery. In continuous-flow operation, the value of average permeation flux was 0.69 m3 m-2 d-1 during without ozonation period, while average permeation flux for 70 days with intermittent ozone bubbling was 1.17 m3 m-2 d-1 that corresponds to 1.7 times that with no ozonation period. Moreover, in spite of intermittent ozone bubbling for 70 days, significant inhibition was not observed for volatile fatty acids (VFAs) producing bacteria and VFAs production. It was found that the average value of [permeates total organic carbon (TOC) concentration: Influent TOC concentration] with ozonation period was about 1.5 times higher than that of no ozonation period. Consequently, it is believed that a membrane-coupled anaerobic VFAs fermenter (MCAVF) process combined with intermittent ozonation is suitable to overcome the flux decline of membrane and simultaneously is useful to the recovery of soluble organic materials from coagulated raw sludge.
Kim
J O
JO
Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-Ku, Kyoto 606-8501, Japan.
Somiya
I
I
D001421:Bacteria, Anaerobic / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors; D005232:Fatty Acids, Volatile / Q000302:isolation & purification* / Q000378:metabolism; D005285:Fermentation; D005374:Filtration; D008567:Membranes, Artificial; D010126:Ozone / Q000737:chemistry*; D010539:Permeability; D012722:Sewage / Q000737:chemistry*
D005232:Fatty Acids, Volatile; D008567:Membranes, Artificial; D012722:Sewage; D010126:Ozone