Two methods of applying activated carbon adsorption treatment to flowing streams were evaluated under comparable conditions. The first involved subsurface introduction of buoyant carbon into the water column followed by the floating of the carbon to the surface and subsequent removal using conventional surface skimming techniques. The second involved the addition to the water of nonbuoyant granular activated packaged in porous fiber bags ('tea bags') which were attached to floats. The bags were allowed to travel with the spill plume for a given distance and were subsequently removed manually. Controlled field experiments using n-hexone as the test chemical were conducted at various flow rates in a specially modified abandoned irrigation channel at the Energy Research and Development Administration's Hanford site and showed that for 'low-flow' nonturbulent conditions the buoyant carbon technique was more effective in removing the chemical from the water with only tolerable amounts of the carbon remaining in the stream. As the flow and turbulence increased the pollutant removal effectiveness of the 'tea bag' approach improved.

Project officers: Ira Wilder and Joseph P. Lafornara. Includes bibliographical references (pages 48-49). Submitted, under the sponsorship of the U.S. Environmental Protection Agency, by Battelle-Northwest, in fulfillment of contracts no.