Concrete sewer corrosion induced by the sulfide oxidation is a long-standing challenge to sewer management. This study presents a novel strategy for reducing the H2S oxidation on corroding concrete surfaces that accommodate an active corrosion biofilm cultivated under sewer conditions. Free nitrous acid was employed to reduce the biological oxidation of sulfide through treating the corrosion biofilm with a spray of nitrite solution. The H2S uptake rates on treated concrete were reduced by 84% -92% 15 days after the nitrite spray. No obvious recovery of the H2S uptake rate was observed up to 22 months after the spray, indicating the long-term effectiveness of the FNA treatment in controlling the activity of the corrosion-causing biofilms. The nitrite is readily transformed by the indigenous microbes in sewage, thus it is a green chemical. Further field trials are still required to verify the effectiveness of this strategy. Nevertheless, it has been demonstrated that the nitrite spray is potentially a very cheap and effective strategy to reduce concrete corrosion in sewers.