Method for removing dissolved-state P507 in saponified P507 wastewater

The invention discloses a method for removing dissolved-state P507 in saponified P507 wastewater, which comprises the following steps: deoiling the saponified P507 wastewater, adding ferric salt and/or aluminum salt into the deoiled and saponified P507 wastewater, adjusting the pH value to 2-6, carrying out a stirring reaction to generate an oily P507-Fe and/or P507-Al organic metal compound, standing after the reaction is finished, and carrying out oil-water separation. According to the method, after saponified P507 wastewater is deoiled, dissolved-state P507 and high-valence iron ions or aluminum ions are fully utilized to form a stable metal complex which is insoluble in water and has the density larger than that of a water phase within a special pH range, so that the dissolved-state P507 can be deeply removed from the wastewater through simple settling separation; the method has the characteristics of simplicity in operation, high removal rate of the dissolved-state P507 extraction agent, low treatment co