Abstract
Hydrothermal t reatment of sludge was carried out, and the effect of hydrothermal conditions such as treatment temperature and treatment period on the filtration performance of the treated sludge was evaluated. The properties of the treated sludge were also analyzed by particle size distribution measurements, pH, and ζ potential, in order to understand the physical filtration mechanism. An increase in treatment temperature significantly improved the filtration capability of the treated sludge. The length of the treatment period also affected the filtration performance; the filtration rate of the sludge subjected to a longer treatment period was increased. Despite a decrease in the particle size of the treated sludge during high-temperature hydrolysis treatment, the filtration capability improved with an increase in the hydrothermal treatment temperature. Significant agglomeration of the treated sludge was not observed, and the agglomeration effect on the filtration performance was fairly small. In addition, the slurry concentration related to the decomposition of organic substances exhibited a significant influence on filtration resistance.
