NOVELTY - The reoxidation of ferrous solutions without formation of nitrogen oxides, comprises contacting hydrogen sulfide gas with an oxidizing acid, filtrating and separating sulfur, reoxidizing a ferrous nitrate to ferric nitrate with a stream containing oxygen enriched air, recycling the ferric nitrate solution and heteropolyacid to oxidation, and discharging air impoverished in oxygen. The ferrous solutions are obtained from the removal processes in continuous of the hydrogen sulfide from gaseous streams.    USE - The invention deals with the reoxidation process of ferrous solutions without formation of nitrogen oxides.    ADVANTAGE - ADVANTAGE -The reoxidation process is cost effective and reduces the impurities produced in the sulfur. The process prevents the precipitation of iron sulfide.    DETAILED DESCRIPTION - The reoxidation of ferrous solutions without formation of nitrogen oxides, comprises contacting hydrogen sulfide gas with an oxidizing acid, filtrating and separating sulfur, reoxidizing a ferrous nitrate to ferric nitrate with a stream containing oxygen enriched air (0.5-30 atmospheres), recycling the ferric nitrate solution and heteropolyacid to oxidation, and discharging air impoverished in oxygen. The ferrous solutions are obtained from the removal processes in continuous of the hydrogen sulfide from gaseous streams. The hydrogen sulfide gas is contacted with the oxidizing aqueous acid solution of the ferric nitrate and contains a heteropolyacid having redox properties. The heteropolyacid is partially salified with an alkaline metal/ammonium. The heteropolyacid is HnXVyM(12-y)O40, where    n = 3-6;    X = phosphorus, silicon, arsenic, boron, and germanium;    y = 1-3;and    M = molybdenum/tungsten.    The sulfur is filtered and separated to produce an oxidizing effect of the ferric nitrate, which is reduced to the ferrous nitrate. The heteropolyacid is in a solid form, which is insoluble in water. The heteropolyacid is obtained from partial or complete salification with cesium, ammonium, potassium, silver and thallium (I), and supporting and immobilization on silica, activated carbon, and on mesoporous molecular sieves such as hexagonal mesoporous silica and mesoporous silica. The gaseous stream consists of natural or associated gas. The ferric nitrate is present in the oxidizing solution in concentrations of 0.01-3 moles/liter. The heteropolyacid is present in the concentrations of 0.01-0.5 moles/liter. Molar ratio of the heteropolyacid/ferric nitrate is 1/1-1/100. The aqueous acid solution has a pH of 0-6. The hydrogen sulfide gas has a concentration of 0.01-100 vol.%. The reoxidation process takes place at a temperature of 20-100degreesC and at a pressure higher than the atmospheric value with a relative pressure of 0.5-50 atm. Partial oxygen pressure is 0.5-30 atm. The oxidation of hydrogen sulfide takes place at a pressure of 1 atm to the pressure of a production well.    DESCRIPTION OF DRAWING(S) - The diagram shows a device for the reoxidation of ferrous solutions without formation of nitrogen oxides:    Softened gas; (2)    Stream; (3)    Recycled oxidizing solution; (6)    Oxygen enriched air; (7)    Gas phase. (8)