03588nas|a2200397 a 4500 20260817162228.0 071112s2007 th uu|m rtt 0| a1eng d .b11890927 AIT Thesis no.EV-07-27 Navaneethan, Navaratnam Anaerobic digestion of waste activated sludge with ultrasonic pretreatment Pathum Thani, Thailand : Asian Institute of Technology, 2007 109 p. : ill. Thesis ; no. EV-07-27 Thesis (M.Eng.) - Asian Institute of Technology, 2007 Ultrasonication of waste activated sludge is usually applied in the enhancement of sludge solubilization and sludge disintegration. This research examines the effectiveness of ultrasound pretreatment on waste activated sludge (WAS) disintegration at different specific energies and sonication durations in the anaerobic digestibility of control, full stream and part stream (50% sonicated + 50% nonsonicated sludge) sonicated WAS. A specific energy of 12 kWs/gTS was the maximum specific energy for the effective disintegration of WAS. The mesophilic digester was operated with SRTs of 20 and 15 days. The ultrasonic pretreatment enhanced the subsequent anaerobic digestibility resulting better removal of TS and VS. The biogas production rate in the full Stream and part stream digesters was increased by 102% and 91% respectively, for a SRT of 20 days in comparison to the control digester, whereas at an SRT of 15 days, the biogas production rate was increased in the full stream and part stream digesters by 81.4% and 57.1 respectively. Although, the specific biogas production was the same in full stream and part stream digesters for both SRTs, which is 0.500 L/g VS removed in a SRT of 20 days and 0.64 L/g VS removed in a SRT of 15 days respectively. The dewaterabilty of the sludge was ranked in the ascending order as full stream, part stream, control digester sludge and raw sludge. Based on the energy balance, energy gained from biogas in the full stream is around two folds compared to energy gained from biogas from control digester. In part stream digester, around 88% of sonication energy input can be replenished in the form of biogas energy. The ultrasonic pretreatment improved the VS hydrolysis coefficient in the full and part stream digesters for both SRTs. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management. Sewage Purification Activated sludge process Visvanathan, C., Chairperson Chongrak Polprasert, Examination Committee Annachhatre, Ajit P., Examination Committee Khanal, Samir Kumar, Examination committee THAILAND (HM Queen), Scholarship donor Asian Institute of Technology. Thesis ; no. EV-07-27 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B10788 .b11890927 mnait u 240404 0 071112 m a u 0 mnait mnarc 22 40 Barcode : 30050120379945 CREATED : 2014-02-13 RECORD # : i12764917 LPATRON : 1026123 LCHKIN : 2017-04-18 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 3 TOT RENEW : 0 Barcode : 30050160049663 CREATED : 2016-05-30 RECORD # : i13003768 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 4362 4362 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT Thesis no.EV-07-27 30050120379945 2026-08-17 16:22:28 3 2026-08-17 22 0 0 0 0 MAIN MAIN mnarc 2026-08-17 0 AIT Thesis no.EV-07-27 30050160049663 2026-08-17 16:22:28 2026-08-17 40