Cyanide Wastewater Treatment

Multiple options for flows with cyanide

There are multiple ways to treat cyanide in wastewater flows, each with different advantages. Saltworks can help you understand your options and implement the solution that bests suits your flow rate, concentrations, discharge limits, and other considerations.

Cyanide Uses and Risks

Cyanide is widely used in many industries and is an important precursor for many organic chemicals such as nitriles. In mining, cyanide is frequently used in the extraction of gold and silver. Cyanide also occurs in nature. Cyanide is carefully regulated in wastewater as many of its compounds are toxic. Fortunately, multiple treatment options are available.
mining tailings point-scaled cyanide
custom mining brinerefine build

Treatment Technologies

Treatment options for cyanide include:

  • Granular activated carbon (GAC) absorbs cyanide, but can result in relatively high costs for both the GAC consumable and its spent disposal. It is best suited for intermittent or seasonal cyanide flows.
  • High-pH bleach oxidation destroys cyanide, producing safe nitrogen gas. Bleach oxidation is well-suited for permanent, continuous, cost-effective treatment.
  • Iron precipitation uses ferrous sulphate to precipitate cyanide. It is also well-suited to permanent cyanide-laden flows.
  • Reverse osmosis (RO) is used to produce safe-to-discharge freshwater with low contaminant levels, including cyanide. The highly concentrated reject is easy to transport for offsite disposal or treatment.

Your Treatment Strategy

Saltworks offers all of the above treatment technologies. The right solution for your process will depend on flow rate, concentration, consistency, required discharge level, and other water chemistry factors.


High-pH bleach oxidation and iron precipitation can be performed by BrineRefine, our flexible, automated chemical treatment system.

RO systems for cyanide treatment require specialized knowledge and plant configuration. Our advanced, ultra-high recovery XtremeRO, may be an option.


We can help you to consider these options and decide on what is best for you and your project. Contact us with your project details to learn more.

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