Recovery of sulfuric acid

Process for the recovery of sulfuric acid from a mixture comprising sulfuric acid and organic matter, comprising the step of contacting said mixture with a selective anion membrane, producing a filtrate flow rich in sulfuric acid and a flow depleted in sulfuric acid content, so that said mixture originates from a contact stage in which the biomass contacts a new flow of sulfuric acid, and in which said new sulfuric acid flow is obtained at least partially from the filtrate obtained by said step of contacting said mixture with said anion selective membrane, and wherein said new sulfuric acid flow further contains sulfuric acid obtained by combustion of H2S, whose H2S is preferably obtained from the step sulfate reduction applied to a flow obtained from said flow exhausted in sulfuric acid content.