In addition to the WAO process, hydrolysis, a technology similar to wet oxidation, can be applied for the treatment of wastewaters when oxygen is not a necessary reactant. In hydrolysis, certain constituents of wastewaters and sludges can react directly with water at elevated temperatures and pressures to yield a treated effluent which is detoxified or meets the desired treatment objective. Wastewaters and sludges which contain cyanide, phosphorus or other hydrolyzable constituents, can potentially be treated by hydrolysis without the addition of an oxidizing agent. Cyanide can react with water to yield formate ion and ammonia. Phosphorus can react with water to yield phosphate ion. A variety of other wastewater constituents can also be treated by hydrolysis to yield environmentally friendly products. When used as a wastewater treatment process, hydrolysis is usually employed as a pretreatment step and is followed by a polishing step, e.g., biological treatment. Common hydrolysis reactions include:
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