| 摘要 |
<p>PURPOSE:To improve a digesting speed and the efficiency of digestion for contriving to increase methane gas, by dividing an anaerobic digestion tank into acid-forming and methane-fermenting zones with retaining plates, returning a part of digested sludge to the methane-fermenting zone, and respectively holding both of the zones at specified temp. CONSTITUTION:An anaerobic digestion tank 1 is divided into a plurality of digestion chambers 3 with holdup plates 2 formed from porous plates or the like, to make the flow speed of a liquid 4 to be treated small. The organic liquid waste 4 is charged in the digestion tank 1 from its one end and let sequentially flow through each of the digestion chambers 3. Hence, acid fermentation is brought out at first by acid-forming bacteria in the digestion chamber 3 at the charging side, the formed organic acid is successively transferred to the next digestion chambers 3, and methane fermentation is brought out by methane-forming bacteria in the digestion chamber 3 at the discharging side. Thus, the interior of the digestion tank 1 is divided into the acid-forming and methane-fermenting zones. A part of sludge 6 discharged from the digestion tank 1 is returned to the central digestion chamber to make the methane fermentation perfect, and the acid-forming and methane-fermenting zones are set up at an ordinary temp. and 30-50 deg.C, respectively, to perform smooth digesting reaction.</p> |
