Process for removing dissolved phosphorus from water magnetically

Claim 1

A process for removing orthophosphate ions from an aqueous solution containing suspended solids, comprising, introducing iron oxide seed material particles at about 100-1000 parts per million in the size range >0.1 microns into said aqueous solution, introducing an electrolyte cation selected from the group consisting essentially of the metal ions A1 + 3 , Fe + 3 , Ca + 2 and Fe + 2 at about 3-10 parts per million into said aqueous solution, said electrolyte cation acting first to associate with itself said orthophosphate ions and, second, to associate through metal ion hydroxo bridges said iron oxide, said bridges having also complexed some of said orthophosphate ions, agitating the solution, allowing a retention time of the order of one to three minutes for a coagulum containing said orthophosphate ions to form, said solution containing sufficient suspended solids to permit said coagulum to form, and then magnetically filtering said aqueous solution to separate the coagulum from the liquid portion of the aqueous solution by passing said aqueous solution at a high flow rate through magnetic filtering means comprising a magnetized filamentary matrix, said high flow rate allowing filter contact time for coagulum removal substantially less than said retention time.