Wastewater

Hydrogen sulfide, ammonia, and other odorous compounds form when wastewater sits under low-oxygen, anaerobic conditions in pipelines and process units. Pumping and turbulence release these gases into the air. Hydrogen sulfide also reacts with moisture on pipe and equipment surfaces to form sulfuric acid, which drives corrosion.

CAIROX^Ⓡ potassium permanganate (solid) and CARUSOL^Ⓡ sodium permanganate (liquid) are strong oxidizers. Injected into wastewater, they destroy hydrogen sulfide, mercaptans, amines, and other odor-causing compounds before they can off-gas.

In municipal collection systems and plants, the primary target is hydrogen sulfide and related reduced sulfur compounds like mercaptans, along with amines. In industrial wastewater, permanganate also oxidizes a broader range of pollutants, including phenols, cyanides, chlorinated solvents like TCE and PCE, chelated metals, aldehydes, and olefins.

The reaction is immediate. In one documented lift station case, hydrogen sulfide readings dropped from a daily peak of 14 ppm to 0 ppm within the first week of treatment.

Typical injection points sit upstream of the odor source: pump stations, wet wells, force main discharges, and plant headworks. In industrial treatment, it’s usually applied ahead of coagulation, settling, or filtration.

Yes. Along with destroying odor compounds, permanganate breaks down fats, oils, and grease. In one lift station case study, a wet well that needed manual grease cleanout every six weeks was down to three cleanouts a year after ongoing treatment.

Not necessarily. Feed rates can be matched to flow patterns, for example a lower baseline dose running continuously with a higher dose added during morning and midday peak flow hours. Dosing can also be scaled back seasonally, since odor and grease formation are typically worse in warm weather.

Lab testing gives a starting estimate, but a plant-scale test under actual site conditions is the most reliable way to set dosage. A rough starting point is one part permanganate by weight for every one part of dissolved sulfide, then adjusted from there.

Yes. It’s used across industrial applications including chemical production and textile manufacturing, to oxidize sulfides, mercaptans, phenols, cyanides, chlorinated solvents, chelated metals, aldehydes, and olefins.

Liquid CARUSOL is typically fed with a chemically compatible metering pump. Solid CAIROX requires a volumetric dry chemical feeder paired with a dissolver and mixing system to get it into solution before it’s introduced. Beyond the feed equipment, no other system changes are generally required.

Yes. By destroying hydrogen sulfide before it converts to sulfuric acid on pipe and equipment surfaces, permanganate treatment reduces corrosion of concrete and steel structures and helps protect electronic and control components.

Yes, when proper handling procedures are followed. Safety is Carus’ top priority. Permanganate is a strong oxidizer and requires the same training and safety procedures as any industrial chemical feed program. Carus provides safety and handling training as part of its technical support to help operators use and manage permanganate safely.

CAIROX is potassium permanganate in solid, dry form. CARUSOL is a pre-mixed liquid sodium permanganate solution, about 20% active ingredient by weight, with a pH between 5 and 8. Liquid CARUSOL is generally the simpler option to feed, since it skips the dry-feed and dissolving step.

In one documented case, hydrogen sulfide in a lift station wet well dropped to 0 ppm within one week of starting treatment and stayed near 0 ppm through the following month.

Cost depends on dosage, flow rate, and site conditions, so it varies by application. In one documented lift station case treating 1.2 million gallons per day, the ongoing cost worked out to about $0.035 per 1,000 gallons. A plant-specific estimate through a treatability study or feed rate assessment is more reliable than applying one case study’s number to a different site.