Goel, Rajeev creator Stoll, Uwe Chairperson Wise, Donald L. Examination Committee Fujii, Shigeo Examination Committee Swedish International Development Authority (SIDA), Sweden Scholarship Donor text series technical report th Bangkok Asian Institute of Technology 1994 continuing eng 114 leaves This experimental study was undertaken on two type of anaerobic pilot scale reactors installed in the premises of a synthetic fiber producing industry. Fixed bed and contact tank reactors of size 3500 l each were used in the study. Contact tank reactor was started by inoculating with sludge of septic tank origin. On the other hand, no seeding was used for the fixed bed reactor as it contained sludge because of its previous operation in treating slaughter house wastewater. Both, the reactors were operated under varying COD loading at different hydraulic retention time (HRT). During the failure of the reactor under higher loading, an increase in the concentration of propionic and butyric acid inside the reactors was observed. This is contemplated to be the major cause of process upset. The maximum organic loading of 2.2 kg COD/m3 .d at HRT of 4.5 days for the fixed bed and 1.3 kg COD/m3 .d at HRT of 7.8 were achieved under stable conditions. Poor immobilization of biomass in the contact tank as compared to the Fixed bed reactor was achieved and this resulted in difference in maximum achievable organic loadings. The batch activity tests are found to be an effective tool to assess the methanogenic activity of the sludge and predicting the state of the reactor. But, inadequate methods of assessing the biomass concentration inside the reactors are seen as a limitation. Simplified process control strategies for detecting the process changes are defined using major process parameters like COD loading, pH, Gas production rate and the concentration of Volatile Fatty Acids. But, these are seen to be inadequate as the proper control action are not defined to run the process optimally. An adaptive control strategy is developed which can be computerized for on-line monitoring and control of anaerobic processes for optimal operation. ·' A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources & Development Thesis (M.Eng.) - Asian Institute of Technology, 1994 Sewage Purification Biological treatment Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B15612 http://203.159.5.9/ait-thesis/detail.php?q=B15612 230399 20260818171925.0