| 摘要 |
A process of purification of waste water by precipitation of magnesium ammonium phosphate (MgNH4PO4.6H20), in which (a) the content of the waste water is determined for the N:P ratio, in which (b) an excess of a magnesium oxide and/or magnesium ions is added and adjustment is made to a predetermined pH-value above 7, in which (c) magnesium ammonium phosphate precipitates in a reactor out of the mixture with the predetermined pH-value and whereby magnesium ammonium phosphate is withdrawn from the reactor into an acidolysis tank, in which (d) adjustment is made to a pH-value below 6,5 in the acidolysis tank, in which (e) magnesium hydro phosphate (MgHPO4) precipitates in the acidolysis tank out of the mixture with the pH-value below 6,5 and this magnesium hydro phosphate is withdrawn from the acidolysis tank, as is an ammonium containing effluent, characterized in that the pH-value in the acidolysis tank is adjusted by injection of carbon dioxide. |
