Abstract: A highly efficient apparatus for burning sulfur to sulfur dioxide and generating sulfurous acid comprises a primary sulfur-burning chamber, a sulfur feed tank closely coupled to the primary chamber, a secondary sulfur-burning chamber, and an absorption tower. Air is introduced to the primary chamber under turbulent, high-velocity flow conditions. Gas passes through the secondary chamber under turbulent flow conditions. The apparatus is capable of converting sulfur to sulfur dioxide at a rate in excess of 25 pounds of sulfur per hour per square foot of surface area of the molten pool of sulfur in the primary chamber.

Abstract: Wastewater is continuously disinfected by combining the wastewater with sufficient acid to reduce the pH of the wastewater to less than about 4 and with sufficient SO.sub.2 that the wastewater has a selected free SO.sub.2 content of at least 5 mg/liter. The combined SO.sub.2 /wastewater is maintained at the selected free SO.sub.2 content for at least about 5 minutes. The wastewater can be treated by dissolving SO.sub.2 into a first portion of the wastewater and combining the first portion with SO.sub.2 dissolved therein with a second portion of the wastewater stream. SO.sub.2 can be stripped from the wastewater, and the stripped SO.sub.2 can be recycled.

Abstract: Wastewater is continuously disinfected by combining the wastewater with sufficient SO.sub.2 that the wastewater has a selected free SO.sub.2 content of at least 5 mg/liter. The combined SO.sub.2 /wastewater is maintained at the selected free SO.sub.2 content for at least about 10 minutes. The wastewater can be treated by dissolving SO.sub.2 into a first portion of the wastewater and combining the first portion with SO.sub.2 dissolved therein with a second portion of the wastewater stream.