| 摘要 |
<p>PURPOSE:To remarkably shorten a time for purifying waste liquid, by supplying water as an upward current while backwashing a filtering agent in a filtering column during charging organic waste matter into a methane fermenting tank and supplying the water as a downward current through the filtering column during withdrawing purified liquid. CONSTITUTION:A methane fermenting tank 6 is a biological reacting cell having air-tight structure provided with an agitating-mixing means, held at a fixed temperature in the range of 20-65 deg.C and controlled at pH 5.5-8.5. Raw waste water 1 is fed into the cell 6 by a pump 20 under the condition that valves 10, 14 are opened while valves 11, 13, 15 are closed, and let flow as an upward current through a filtering column 7 provided with a filter-packed layer 8 on the way. The raw waste water 1 may be organic waste water or waste sludge formed from cities or various kinds of industrial fields. The inflow speed of the raw waste water 1 must be a value to form the upward current having a flow speed enough to cause the interlayer expansion of the filter-packed layer 8, but may be properly determined from the specific gravity, particle size, etc. of the filter.</p> |
