The interaction of ferrous ions and phosphorous was studied under aerobic conditions in order to assess effectiveness and feasibility of phosphorous removal.Using Fe(Ⅱ)/O2 and conventional technologies the removal effectiveness of phosphorous in a real electronic waste water and relative economic indicators was compared.For Fe(Ⅱ)/O2 system the effect of co-existing cations in simulating natural liquid on efficiency of phosphorous removal was examined using variables analysis.The results show that there was no effect of NH4+-N on phosphorous removal by Fe(Ⅱ)/O2 oxidation.Precipitation could occur between Zn(Ⅱ) and phosphorous in the system

which could promote removal of phosphorous and decrease of ferrous iron consumption.Mn(Ⅱ)as well as OH- could form complexes with Fe(Ⅲ)generated newly

the complexes are capable of hastening ferrous iron oxidation and also of improving the coagulation of Fe-P sedimentation.As the inventory of Mn(Ⅱ)increased from 0 to 1 mg·L-1

the removal rate of phosphorous raised 11% after 60 min reaction.Cu(Ⅱ)could remarkably increase the efficiency of phosphorous removal by its catalytic effect.As Cu(Ⅱ)concentration increased from 0 to 0.05 mg·L-1

the reaction time required 45% phosphotous removal could be reduced from 60 min to 5 min.For a real electronic wastewater the phosphorous removal was better for Fe(Ⅱ)/O2 system in the presence of the above mentioned cations than for lime alone

while sludge production and economic cost was lower for the former than for the latter.