A "marker" technique to monitor treated industrial wastewater effluents

In toxicological research with hazardous substances (e.g. carcinogens), wastewater effluent from the test facility must be free of such substances before discharge into the environment. An industrial wastewater processing employing adsorbers of carbon and XAD-2 resin is described; however, chemical assays of each batch of treated effluent must certify the absence of all test agents. Elution profiles and adsorption isotherm tests with the test agents vs. the two adsorbents provided the basis for a "marker" technique which should eliminate the necessity to assay for all test agents in each batch of processed effluent. A radionale is presented for periodic introduction of a "marker" (gentian violet) into the primary adsorbers. If detected in the effluent, the "marker", which elutes from the adsorbers before most of the test agents would signal impending depletion of the adsorbent which could then be replaced. Recommendations to modify the industrial wastewater treatment plant and to implement the "marker" technique are presented as cost-effective alternatives to extensive and laborious chemical assays.