Hydrogen cyanide wastewater treatment process

FIGURE 22.10 General wastewater treatment process flow diagram at a typical hydrogen cyanide plant. 

Some other types of treatment processes that can be employed in the hydrogen cyanide industry include ozonation, to oxidize the wastewater chlorine. Potency of sulfur oxide is also high in the oxidation process. 

Wastewater can be treated by a variety of chemical processes, including acid/base neutralization, precipitation, and oxidation/reduction. Sometimes these steps must precede biological treatment for example, acidic or alkaline wastewater must be neutralized for microorganisms to thrive in it. Cyanide in the wastewater can be oxidized with chlorine and organics with ozone, hydrogen peroxide promoted with ultraviolet radiation, or dissolved oxygen at high temperatures and pressures. Heavy metals can be precipitated with base, carbonate, or sulfide. 

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