Abstract
Kamigoto-Koiki Clean Center is the sludge recycling center at Nagasaki Prefecture. This has the high-rate thermophilic methane fermentation equipment. We had begun the operation of this equipment using mesophilic digested sludge because it was difficult to get thermophilic one. But this method has following two challenges : (i) it is quite important to control temperature and organic loading rate (OLR), and the wrong control may cause sour that stops fermentation. (ii) the start-up demands a longer span, usually more than a few months, because of acclimation of bacteria. In order to solve these problems, we had monitored not only temperature and OLR but also biogas production, soluble COD_<Cr> (S-COD_<Cr>), total volatite fatty acid (TVFA) and pH. As a result, the start-up had been successful for about three months.
