Abstract
Above 200,000 ton/year of paper sludge (PS) ash are discharged at Fuji area of Shizuoka prefecture in Japan, therefore, effective utilization of the PS ash is strongly desired. We attempted to synthesize calcium-silicate-based ceramics, which would function as good absorbent for heavy-metal ions, by calcination of the PS ash with sintering binder, such as waterglass solution and powder of oyster′s shell. The calcination was carried out in air at the heating condition of 2 steps, i.e., at 540°C for 10 h and at 840°C for 24 h.The adsorbability of the ceramics for the heavy-metal ions as functions of pH, temperature and so on was evaluated, and the potential of the ceramics as a purifying material for metal-rich wastewater was investigated.
