Chen, Ann-cheng creator Harada, Hideki Chairperson Tran, Francis T. Examination Committee Verink, Johan Examination Committee Chinese Taipei Government Scholarship Donor text series technical report th Bangkok Asian Institute of Technology 1991 continuing eng 70 p. This study was aimed to cultivate thermophilic organisms which can perform optimally at 55°c, and to utilize their increased reaction rate at increased temperature. A semi-pilot modified U.A.S.B. reactor were operated at different organic loading of 2 to 24 Kg COD/m3.day corresponding to H.R.T.:12o hr to 10 hr and using distillery wastewater as feed substrate which was inherently at high temperature. Investigations on gas production rate, biogas composition, COD balance, sulfur balance, microbial and physico-chemical mechanism of granular sludge formation were made. It was determined that organic loading up to 24 Kg COD/m3.day could be handled with satisfactory efficiency. High methane production rate was linearly increasing correspondingly with increasing organic loading. Higher organic loading was still imposed continuously, that is, maximum organic loading was not obtained yet. It was found that limiting step of thermophilic U.A.S.B. reactor was propionate degradation. The interspecies hydrogen transfer in the system was very important factor for process performance. Based on COD balance, 68% of removal COD was converted to methane gas. Also it was found that sulfate reducing bacteria can not compete with methanogenic bacteria in the system. Both Methanosarcina-like and Methanothrix-like methanogens were coexisting in granular sludge. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering Thesis (M.Eng.) - Asian Institute of Technology, 1991 Sewage Purification Activated sludge process Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B17411 http://203.159.5.9/ait-thesis/detail.php?q=B17411 170399 20260819084530.0