Abstract
Further treatment of waste water in the chemical industry by use of activated carbon. Biological treatment has proved to be no longer adequate for numerous waste water streams emitted by chemical plants. Some of the pollutants entrained by the waste water feature poor biodegradability, and certain compounds even have a detrimental effect on the microorganisms of the activate sludge. Adsorption by activated carbon is one of the potential methods for eliminating such substances. Explanations refer to the physical phenomena of the process. Adsorption may be performed prior to or after biological treatment. Commercial‐scale plants use granular activated carbon and use an intermittent process (fixed bed) or a continuous process (countercurrent adsorber). Possibilities and aspects are exemplified by plants using this process. Operating results are presented. A recent development combines the biological and adsorptive treatment which is based on the continuous admission of powdered activated carbon into the activated‐sludge basin. Results obtained in a demonstration plant will be discussed. Cost‐effective application of this technology is, however, conditional upon reactivation of spent carbon.