Emulsion Liquid Membrane Extraction of Selenium from Refinery WastewatersEPA Contract Number: 68D40069
Title: Emulsion Liquid Membrane Extraction of Selenium from Refinery Wastewaters
Investigators: Wright, John D.
Small Business: TDA Research Inc.
EPA Contact: Manager, SBIR Program
Project Period: September 1, 1994 through December 1, 1997
Project Amount: $165,000
RFA: Small Business Innovation Research (SBIR) - Phase II (1994) RFA Text | Recipients Lists
Research Category: Water and Watersheds , SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)
Description:Selenium is presently the primary water treatment challenge for many West Coast petroleum refineries and is also present in significant quantities in agricultural drainage from irrigated farm lands. Because of its known toxicity and suspected carcinogenicity, the discharge limits are set by the Clean Water Act are very low (0.260 mg/L maximum, 0.035 mg/L continuous for selenium). Processes developed for selenium removal from drinking water are too expensive for the treatment of industrial wastewaters. For these processes to achieve high removal efficiencies, the selenium must be present as only one anionic species, and competing anions like sulfate or carbonate must not be present.
Therefore, TDA Research proposed using Emulsion Liquid Membranes (ELM) to remove selenium from contaminated waters. In Phase I, they demonstrated the feasibility of the ELM process in both batch and continuous counter-current extractions and carried out an economic analyses to compare their ELM process with other competing processes. In Phase II, they will demonstrate an integrated continuous treatment process including not only the ELM extraction, but also emulsion preparation, emulsion coalescence, membrane recycle and reuse. The Phase II effort will conclude with a field demonstration of the continuous process on an actual selenium contaminated process stream.