In a refinery tank remediation (Italy, Nov 2022), Akka2O ARiAGuard® reduced H₂S from 50–70 ppm to <5 ppm, enabling safer, faster “gas-free” operations and final cleaning with Akka2O CLEaRGrease®.
Why H₂S remediation matters
Hydrogen sulfide (H₂S) is toxic, corrosive, flammable, and highly dangerous. In industrial settings—refining, gas processing, wastewater treatment, and organic decomposition—controlling H₂S is essential to protect workers, prevent atmospheric releases, and meet safety requirements prior to tank entry.
Project objective
This intervention focused on two priorities:
Eliminate flammable/toxic gases and vapors that could cause fires/explosions during inspection or maintenance.
Create gas-free conditions to protect worker health during confined-space entry and comply with industry safety procedures.
Methodology: microemulsion neutralization + controlled spraying
Akka2O ARiAGuard® is applied as a microemulsion (ARiAGuard® + a carrier fluid such as water). When it contacts H₂S, it neutralizes the gas through gelling, precipitation, and encapsulation, converting it into non-hazardous inert sulfur compounds (e.g., insoluble metal sulfides).
Operational sequence (field-ready workflow):
Phase 1 — Initial nebulization from the manhole: reduce gas levels before entry.
Phase 2 — Internal spraying (15–40% solution): treat walls and internal areas once acceptable levels are reached (operators with SCBA).
Phase 3 — Final washing (Gas-Free): after sludge extraction, Akka2O CLEaRGrease® supports final cleaning with significant time and water savings.
Results: measurable reduction, safer access
Baseline H₂S (before treatment): 50–70 ppm
After Phase 1 (2–3 hours, 120–140 L nebulized): ~15 ppm
After Phase 2 (internal spraying): < 5 ppm These outcomes demonstrate rapid reduction of H₂S to operationally safer levels, supporting tank entry and subsequent cleaning activities.
Key takeaways
Fast knockdown of H₂S to enable safer maintenance workflows.
Operational practicality: staged approach from external nebulization to internal treatment.
Efficiency at the end of the process: CLEaRGrease® supports final washing with reduced time and water use.
