This research was conducted for dewatered sludge cake of industrial wastewater treatment, i.e., as the object of inorganic sludge discharged especially in iron & steel manufacturing shop which used Air drying system to reduce water content. That drying system's single-type cyclone separator was confirmed to have significantly lower separation efficiency on the conditions 20μm and below of particular size through computational fluid dynamics(CFD) analysis. However, we found out the primarily advanced value of separation efficiency on dual-type directly connected. Regarding separation efficiency on size of 10μm, the efficiency of a single-type was presented at 51.91%. On the other side, the efficiency of the dual-type was 97.88%. This advanced effect of the dual cyclone separator was checked at a demo facility of air drying equipment designed by 340m3/min of airflow on site.

The performance of the new aerobic digestion system combined with inorganic sludge separation unit and sludge solubilization unit, CaviTec II, is evaluated. Anaerobic digester effluent sludge is used for feed sludge of CaviTec II system. By addition of CaviTec II, the amount of cake generated is reduced by 27%, and the soluble nitrogen is reduced by 92%.

The performance of inorganic sludge separation system is evaluated. Anaerobic digester effluent sludge is used for feed sludge of this system and hydrocyclone is used for inorganic sludge separation. For phosphorus removal and recovery MgCl2 is pumped into MAP growth tank, a component of inorganic sludge separation system. Using this system inorganic sludge which contained less than 40 % of organic matter can be discharged stably and the maximum amount of separated inorganic sludge is 13.4 % of influent sludge based on dry solid. The amount of phosphorus recovered as MAP(as P) is 16.7 % to influent T-P.