ENV-95-167 TREATMENT OF REFINERY WASTEWATER TOXICITY VIA SELECTIVE RESIN ADSORPTION

Description:

Acute and chronic wastewater toxicity continues to plague many refiners struggling to meet NPDES mandated discharge standards. Refinery wastewaters are generally complex mixtures comprised of multiple constituents making identification and reduction of problematic (toxic) compounds more difficult. Chevron Research and Technology Company (CRTC) has found a common class of partially polar compounds contributing 95 percent of the observed wastewater toxicity within all refinery and terminal facilities tested CRTC teamed with International Technology Corporation (IT) to further test and confirm a patented process (Pat. # 5,235,594), known as the Toxicity Reduction Adsorption Process (TRAP), in the efficient adsorption and subsequent removal of these common toxicants from refinery wastewater streams. IT and CRTC investigators tested this non-ionic resin based technology on a large refinery discharging to marine waters of the Gulf of Mexico. The 1.5 year long joint study proved the TRAP resin approach to be much more selective in the adsorption of toxic partially polar organ& These ubiquitous toxicants have been found to comprise only 2 percent of a refinery wastewater Total Organic Carbon (TOC) load, making their selective separation and removal from other organic carbon of paramount importance in the efficient and cost effective treatment of toxicity. The TRAP technology adsorbed the toxicant fraction of wastewater TOC loads as measured by sub-chronic Men&u and Mysid bioassays in multiple testing rounds. Refmery wastewater samples exhibiting chronic toxicity values of 17 percent to 70 percent wastewater were rendered non-toxic following employment of the TIUP approach. The observed reduction in toxicity was coincident with very little reduction in TOC, confirming the selectivity of the resin tested Given the superior performance of the TRAP resin in regards to selective removal of problematic compounds, as compared to conventional carbon treatment, this new toxicity reduction approach may offer refiners a more efficient and, therefore, cost effective means to bring their facilities into compliance regarding wastewater toxicity via treatment at the point of final discharge or “upstream” where the toxic organics are more concentrated