| 摘要 |
<p>PURPOSE:To improve the ratio of recovering energy by methane fermentation, in fermenting natural organic waste matter or organic industrial waste water into methane gas, by adding fibrous substance-contg. waste water to water to be purified overflowing from a fermenting vat. CONSTITUTION:Organic waste matter, e.g. sludge, night soil or sewage sludge, or industrial waste water 4 containing a large amount of organic substance is introduced into a mixing cell 1 where various kinds of nutritive salts 5 are added to and mixed with it, and supplied to a fermenting vat 2 by a pump 15. The organic substance is fermented by heating it with heating steam 8 to form methane gas 9, and then the waste matter is fed into a precipitating cell 3 where the waste matter is separated into purified water 14 and digested sludge. At this time, waste water 11 contg. fibrous substance such as fibrous refuse or sludge is added to the precipitating cell 3, and the digested sludge is returned through a returning pipe 13 to the fermenting vat 2 by a pump 17 and fermented into methane gas. In this way, the ratio of recovering energy as methane formed by the fermentation of organic substance is improved.</p> |
