| abstract |
PURPOSE: To efficiently remove the microbial hardly-decomposable component in a sludge-eliminated liquid by applying primary biological treatment to the sludge eliminated liquid to reduce BOD and total nitrogen concn. and subsequently irradiating the treated liquid with ionizing radiation and further again applying secondary biological treatment thereto. n CONSTITUTION: A sludge eliminated liquid is subjected to primary biological treatment at first to reduce a BOD value and total nitrogen concn. to 30ppm or less, pref., to 10ppm or less. Next, air or oxygen is passed through the eliminated liquid to dissolve oxygen therein and, thereafter, said liquid is irradiated with ionizing radiation and further subjected to secondary biological treatment. As the aforementioned ionizing radiation, there are α-rays, a deuteron, β-rays, electron beam, γ-rays and X-rays. By performing the aforementioned treatment, microbial hardly-decomposable component and COD can be reduced to sufficiently low concn. with respect to various sludge-eliminated liquid. n COPYRIGHT: (C)1990,JPO&Japio |