| 摘要 |
<p>PURPOSE:To reduce the generation of a flocculated sludge and excess sludge significantly and further, cut the consumption of an inorganic flocculation agent by removing phosphorus from an organic contaminated water and recycling phosphorus as a resource. CONSTITUTION:In a step to treat an organic contaminated water 6 containing phosphorus biologically, the phosphorus is made insoluble by adding a ferrous flocculation agent 7 or iron hydroxide 7, then the insoluble phosphorus product is settled together with activated sludge, and an alkali agent 14 is added to a sedimented sludge 9 to elute 15 phosphorus from the sludge. Further, the activated sludge is made soluble, then the solid is separated 16 from the liquid, and the separated sludge 18 is supplied to a biological treatment step, while the separated liquid has phosphorus recovered by adding a chemical to make phosphate ion insoluble to the separated liquid and the extracted phosphorus is fed to the biological treatment step. Thus, the organic contaminated water containing phosphorus is treated.</p> |
