含藻污泥脫水調理之研究

Abstract

Water reserviors, major sources of water supply in Taiwan, have been partiallypolluted and become eutrophic, thereby resulting in the existance of algae inwater treatment operation. In general, the algae in source water can be removed by the flocculation and sedimentation process and incorporated in the sludge.The sludge containing algae appears more complex structure and its behavior isclose to the mixture of chemical and biological sludge. The species and quantity of algae on or in the sludge affect the surface properties, electronic characteristics, and the distribution of moisture as well as he following conditioningand dewatering performance.Polymer conditioning is commonly applied to reduce the coast of dewatering byimproving the dewatering characteristics of sludge. We propose an approach to investigate the floc structure and moisture distribution of sludge under the different mixing intensity, duration and polymers types. However, there is stilla little informance about the influence of algae and their exudates on the sludge conditioning as well as dewatering.In this study, we have applied the dilatometer to measure the bound water content, and the fractal analysis to investigate the change of floc structure. The results find that the cationic polymer and optimal dose of polymer can effectively reduce the bound water content and significantly improve the dewaterability of sludge. However, the overdose of polymer cause an increase of bound water content and a reduction of dewaterability of sludge. It also indicates, through the fractal analysis, the increase of bound attributes tothe decrease of effective density as the sludge floc aggregates during the conditioning.