Thermophilic anaerobic wastewater treatment : temperature aspects and process stability

摘要: The main objective of this thesis was to assess the thermostability thermophilic anaerobic wastewater treatment processes and possibility optimize performance high-rate systems. Experiments were conducted study suitability two types seed material start a process. Both mesophilic granular sludge digested organic fraction municipal solid waste used as inoculum. fate under conditions studied in detail. Due temperature increase methanogens are replaced by thermophiles. In fact, granules appeared serve mainly carrier for bacteria during start-up. Since organisms attach quite well, specific methanogenic activity increased very rapidly period. Treatment completely acidified leads deterioration 'mesophilic-thermophilic' granules. It therefore extremely difficult develop on type both inocula. However, granulation process proceeded easily when sucrose added influent. sensitivity various depends strongly applied, such reactor type. Thermophilic cultivated reactors with high solids retention shows thermostability. Therefore, can be applied wide range, even conditions. contrast, batch is sensitive relatively small variations. Regarding process, application preferred over or mixed reactors. presence enhances stability towards fluctuations substantially. maximum limited mass transfer rate. Consequently, 'biomass buffer' created which drawn if drops result decrease. A removal efficiencies obtained upflow staged bed (USSB) extreme loading This USSB consisted 5 compartments along height. From each separate compartment produced biogas withdrawn. major effect staging low concentration intermediate products, hydrogen acetate, last system. these products degradation all fatty acids. properties grown depend environmental prevailing compartment. withdrawal excess should performed from first an used. Otherwise, stable operation long term cannot guaranteed because voluminous acidifying will eventually force out active acetogenic consortia subsequent compartments.