03325nam a2200445 a 4500 20260818214207.0 .b10606166 En AIT Thesis no. EV-94-29 Yuthana Tanwongwan Sludge bulking and its control in modified A/O processes Bangkok : Asian Institute of Technology, 1994 83 leaves Asian Institute of Technology. Thesis ; no. EV-94-29 A thesis submitted in partial fulfillment of the requirement for the degree of Master of Science, School of Environment, Resources & Development Thesis (M. Sc.) - Asian Institute of Technology, 1994 It is known that A/O process can produce well-settling sludge. But sludge bulking can also occur in these processes due to some causes such as composition of wastewater, operating conditions, and, configurations of the systems. From this experiment, it has been observed that 0.2 mIJL of acetic acid can cause zoogloea bulking in A/O processes which had only two anaerobic tanks but the process that had three anaerobic tanks can control this kind of bulking. It also has been observed that strictly anaerobic initial contact zone (ICZ) can suppress filamentous bulking more effective than anoxic one. Furthermore, some of unsuitable operating conditions , i.e. too low organic loading, too high return sludge ratio, and too long influent hydraulic retention time can deteriorate sludge settleability and phosphorus removal efficiency but improve the removal efficiency of nitrogen. Additionally, it has been found that concept of contact stabilization activated sludge, i.e. reaeration of return sludge, is difficult to be applied with A/O process because it can introduce small amount of dissolved oxygen into ICZ so filamentous bacteria can use this 00 as electron acceptor in their metabolic mechanisms. Floes in units which had reaeration were very small siz.e and not compact. Sewage Purification Activated sludge process Samorn Muttamara, Chairperson Lee, Seong-Key, Examination Committee Umita, Teruyuki, Examination Committee Royal Thai Government, Scholarship Donor Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B15803 .b10606166 mnait - 240410 2 951012 m a - 0 AIT Thesis no. EV-94-29 mnait b m 099 30050001131381 mnait 30050001131399 c. 2 mnait mnait mnait mnarc 20 40 Barcode : 30050003048005 CREATED : 1994-05-18 RECORD # : i10767812 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050003048013 CREATED : 1994-05-18 RECORD # : i10767824 LPATRON : 1012460 LCHKIN : 1999-07-25 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 1 TOT RENEW : 0 Barcode : 30050160055322 CREATED : 2016-11-05 RECORD # : i1297559x LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 107586 107586 0 0 0 0 MAIN MAIN mnait 2026-08-18 0 AIT Thesis no. EV-94-29 30050003048005 2026-08-18 21:42:07 1 2026-08-18 20 0 0 0 0 MAIN MAIN mnait 2026-08-18 0 AIT Thesis no. EV-94-29 30050003048013 2026-08-18 21:42:07 2 2026-08-18 20 0 0 0 0 MAIN MAIN mnarc 2026-08-18 0 AIT Thesis no. EV-94-29 30050160055322 2026-08-18 21:42:07 2026-08-18 40