fig1 is placed between the exit of the first decanter 22 and the entry of a second electrolytic reactor 26 this automatic dosing device allows the adjustment of the quantity of orthophosphate in the effluent needed to react with all the nh 4 in solution after this second conditioning step the effluent is introduced in a second electrolytic reactor 26 which also comprises a fixed electrocoagulation module 20 the second electrolytic reactor 26 comprises in its fixed electrocoagulation module 20 at least one soluble anode made of magnesium the ions mg 2 generated while applying the electrical current react with the nh 4 and orthophosphate in solution and therefore produce a struvite precipitate both first and second electrolytic reactors 18 and 26 optionally comprise a motor 70 allowing the rotation of the electrocoagulation module 20 providing for an additional agitation of the fluid in the reactors 18 and 26 after this second electrolytic treatment the effluent is brought in a second decanter 28 for isolating the struvite precipitate an exemplary electrocoagulation module 20 is illustrated in fig2 with a section view allowing a better view of its construction the electrocoagulation module 20 comprises an anode module 30 and a cathode module 32 adapted to interact in an electrolytic process producing electrocoagulation the.