| 摘要 |
PCT No. PCT/SE91/00582 Sec. 371 Date Mar. 8, 1993 Sec. 102(e) Date Mar. 8, 1993 PCT Filed Sep. 4, 1991 PCT Pub. No. WO92/04284 PCT Pub. Date Mar. 19, 1992.A method of reducing nitrogen, phosphor, and excessive biological oxygen demand (BOD) in wastewater supplied to and passing through a granular filter bed activated with bacteria includes in the flow direction of the wastewater through the bed simultaneously precipitation of phosphorous, denitrification and reduction of the excessive BOD in a single process step. The reduction of excess BOD is produced by blowing in an oxygen-containing gas, preferably air. Immediately before the wastewater enters the filter bed a precipitation/flocculation agent may be added for precipitation of phosphor. |
