REMOVAL OF TETRACHLOROETHYLENE CONTAINED IN DRY CLEANERS?WASTEWATER

摘要

A treatment system was invented in 1998 and U.S. (Patent No. 5674389) wasrnobtained. In the particular system embodying the invention, wastewater containing arnminor percentage of tetrachlorethylene (commercially called "perc") impurity in arnconcentration of about 200 milligrams more or less impurity per one liter ofrnwastewater, is passed sequentially through a first inertial separator action, and arnsecond adsorption stage for removing the remaining impurity by selective adsorptionrnof the impurity out of the pretreated wastewater. The impurity adsorption stage removesrnsubstantially all of the impurity not removed by the inertial separator stage. Thisrnparticular system is in addition to the existing separator box attached to the dryrncleaning machine.rnThe adsorption stage comprises a plurality of upstanding two, three or four adsorptionrncolumns. Each adsorption column comprises an upstanding tubular housing thatrnsupports a vertical adsorption bed containing clay granular material (montmorillonite,rnwhich has ion exchange capacity between 70 to 90 meq/gram) and activated charcoal