International Journal of Waste Resources

Abstract

Effects of Hydrothermal Process on the Nutrient Release of Sewage Sludge

Sun XH, Sumida H, Yoshikawa K, Sumida H, Yoshikawa K

Hydrothermal treatment has demonstrated the ability of improving the dehydration and drying performances of sewage sludge, as well as shown its suitability for producing fuel. On the other hand, because of the abundant nutrient matters in sewage sludge, the produced liquid may be used as the liquid organic fertilizer. In this work, the effect of the hydrothermal treatment on the nutrient behavior in sewage sludge was investigated. The effects of the reaction temperature (180-240°C), and the reaction time (30-90 min) were investigated, and both of solid and liquid products were analyzed individually. The results showed that 40%-70% of nitrogen, 50%-70% of potassium and 10%-15% of phosphorus in sewage sludge could be dissolved into the liquid product, and that the solubilization was highly influenced by the temperature and the reaction time during the hydrothermal process. The hydrothermal treatment can effectively transport nutrient components in sewage sludge into the liquid product.