Treated waste streams

Thermal oxidation is another alternative for destroying cyanide. Thermal destruction of cyanide can be accomplished through either high-temperature hydrolysis or combustion. At temperatures between 140°C and 200°C and a pH of 8, cyanide hydrolyzes quite rapidly to produce formate and ammonia.23 Pressures up to 100 bar are required, but the process can effectively treat waste streams over a wide concentration range and is applicable to both rinsewater and concentrated solutions22 ... 

In testing, this technology was effective in treating waste streams contaminated with benzene, toluene, ethylbenzene, and xylenes (BTEX compounds). The technology is not in use at present and is not commercially available. 

The vendor indicates the technology can treat waste streams containing solvents, petroleum distillates, chlorinated solvents, pesticides and herbicides, as well as phenolic wastes, pulping liquors, municipal sewage, and industrial sludges. 

Potential applications include treating VOC-contaminated airstreams from air-stripping, industrial air emissions, and cleaning air in closed environments. PCO is best suited for treating waste streams with low concentrations of contaminants and with low to medium flow rates. The technology is commercially available. 

Can treat waste streams with high levels of suspended solids without pretreatment. 

Systems are generally limited to treating waste stream solutions and slurries containing 2 to 25% organics with a maximum particulate size of 100 p,m. 

Does not use a large quantity of chemicals or energy to treat waste streams containing both acids and metals. 

Air stripping. Air stripping is used to reduce the concentration of noxious gases, for example, ammonia, and hydrogen sulfide, from biologically treated waste streams. It can also be used to remove volatile... 

The advantages of this process arise finm the fact that the system does not t3q)ically require chemicals and, therefore, the decomposition of organics is an environment-friendly degradation process. However, this process has limitations and cannot handle slurries, tars, or a high concentration of suspended solids. In fact, this process has been used extensively to treat waste streams from iron and steel, pulp and paper, petroleum refining, organic chemical manufacture, and pharmaceutical industries. 

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