Removal of hydrogen sulfide from an oil-containing mixture having a continuous aqueous phase

A method for removing hydrogen sulfide from a mixture comprising a continuous aqueous phase having a pH greater than 6 and a first oil phase, the method comprising the steps of:

• (a) introducing a composition selected from the group consisting of sulfur dioxide and sulfur dioxide precursors into the mixture;
• and
• (b) introducing an acid into the mixture, the total amount of the composition and acid introduced into the mixture being sufficient to form a treated mixture comprising a continuous aqueous phase having a pH less than 6 and a second oil phase, the pH of the aqueous phases being measured at ambient conditions.

A method for removing hydrogen sulfide from a mixture comprising a continuous aqueous phase having a pH of at least 6, the method comprising the steps of:

• (a) introducing a sufficient amount of an oil product to produce a modified mixture containing at least 5 volume percent of oil product and less than 95 volume percent water, the volume percents being based on the total volume of the modified mixture;
• and
• (b) introducing a sufficient amount of sulfur dioxide into the modified mixture to form a treated mixture comprising a continuous aqueous phase having a pH less than 6 and an oil phase, the pH of the aqueous phases being measured at ambient conditions and the treated mixture being devoid of a sulfur sludge.

A method for removing hydrogen sulfide from an untreated mixture comprising a first oil phase and a continuous aqueous phase, the method comprising the step of introducing a sufficient amount of sulfur dioxide into the untreated mixture to form a treated mixture with a pH less than 6 comprising a second oil phase and a continuous aqueous phase having a pH less than the pH of the continuous aqueous phase of the untreated mixture, the pH of the aqueous phases being measured at ambient conditions and the treated mixture being substantially devoid of a sulfur sludge.

A method for removing hydrogen sulfide from an untreated mixture comprising a first oil phase and a continuous aqueous phase, the method comprising the steps of:

• (a) introducing a composition selected from the group consisting of sulfur dioxide and sulfur dioxide precursors into the untreated mixture;
• and
• (b) introducing an acid into the untreated mixture, the total amount of the composition and acid introduced into the untreated mixture being sufficient to form a treated mixture with a pH less than 6 comprising a second oil phase and a continuous aqueous phase having a pH less than the pH of the continuous phase of the untreated mixture.