Technology Options for the Treatment of Wastes and Waste Streams

Technology Options for the Treatment of Wastes and Waste Streams 

Before the selection of a specific treatment technology can be made, an understanding of the site-specific factors which drive the selection of that technology is required because these factors can influence the evaluation of the advantages and limitations of competing technologies. The information required to resolve these site-specific issues falls into four categories waste composition and matrices, waste quantity, treatment objectives, and the reactions involved in the treatment of the contaminated material. 

To understand chemical treatment processes, it must be remembered that a reaction is not a process. A reaction involves the chemical transformation of a material, whether this is carried out on a lab-scale or an industrial-scale. A process, on tbe other hand, is a series of actions or operations needed to make such a reaction occur in a controlled manner. Thus, the development of a process requires the design of the 

Chemical treatment processes rely on the intimate mixing of reagents with the waste. Thus, the wastes generally treated by chemical means must be in an aqueous or slurry form. 

144 Handbook of Emergency Response to Toxic Chemical Releases 

The function of pH adjustment is to neutralize acids and bases and to promote the formation of precipitates (especially of heavy metal precipitates) which can subsequently be removed by conventional settling techniques. These purposes are not mutually exclusive, precipitates can be formed as the result of neutralizing a waste. Conversely, neutralization of the waste stream can result when adjusting the pH to effect chemical precipitation. Typically, pH adjustment is effective in treating inorganic or 

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