Rhodobacter sphaeroides Suwasa Kantawanichkul creator Chongrak Polprasert Chairperson Yamamoto, Kazuo Co-Chairperson Vigneswaran, Saravanamuthu Examination Committee Mino, Takashi Examination Committee Athapol Noomhorm Examination Committee Somiya, I. Examination Committee Royal Norwegian Government Scholarship Donor text series technical report th Bangkok Asian Institute of Technology 1990 continuing eng 113 p. The hollow fiber membrane bioreactor combined with photosynthetic bacteria ,Rhodobacter sphaeroides was proved to b e suitable for only wastewater treatment The hollow fiber membrane enhanced the removal of grease and oil efficiency t o over 90% while the degradation by photosynthetic bacterial one could achieve 65-75%. The hollow fiber membrane was also necessary for solid/liquid separation since the settle able sludge of t his bacteria was only 10 ml/l in 30 min. which is difficult to settle b y gravity. Sludge treatment and disposal were not needed for this system since bacterial cells in the sludge can be directly used as sing l e cell protein for animal feed and fertilizer . The protein content o f the wasted sludge was 40% which was high enough to be used as single cell protein. Under long solid retention time ( SRT) of 3 0 d a nd s h or t hydraulic retention time (HRT) of 1. 5 d, maximum ML SS concentration of 3 , 910 mg/l could be obtain e d, and under short SRT ( 5 d ) and short HRT (1 .5 d), the maximum biomass harvested per d ay (660 mg/ d) was achieved. Too s h ort HRT caused clogging of the membrane a nd too short SRT caused cell washout of the system . When high organic loading (8 kgCOD/(m3 .d)) or high hydraulic loading (1.3 m3 /( m3 .d )) was applied to the system, the high concentration of grease and oil occurred a nd inhibited t h e bacterial growtl1 in the reactor. Never the less, the system was proved to b e stable to high organic loading and high hydraulic loading (8 kgCOD/(m3 .d) and 1. 3 m3 /(m3 . d ) respectively ). The COD removal efficiency of the system was 70 - 85%, and further treatment by other bio- oxidation processes is necessary. Batch study in small bottles was a l so conducted to study t h e performance o f Rhodobacter sphaeroides. The inoculum size of 596 was suitable for the system. The growth rate a nd the removal efficiency of this bacteria were more active under continuous illumination than under intermittent illumination either by artificial or s un light. The kinetic coefficients of Rhodobacter sphaeroides (æm, Y, Ks and kd ) were d e t ermine d. The value of kd for the bioreactor with membrane was bigger than the bioreactor with out membrane. This was possibly caused by some attached growth a t the membrane fibers which reduced the MLSS concentration in the reactor . A dissertation submitted in partial fulfillment of the requirements for the degree of doctor of technical science, School of Environment, Resources and Development Thesis (Ph.D.) - Asian Institute of Technology, 1990 Sewage Purification Oil removal Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B18151 http://203.159.5.9/ait-thesis/detail.php?q=B18151 160699 20260817162908.0