Treating chlorinated solvents in groundwater with synthetic adsorbents

Groundwater

Project highlights and product features

  • Installed by ECT’s parent company, design treats 20 to 30 gpm continuously from near saturation concentrations to ND @ at 5 ppb
  • System has been operating since 1999, with over 5,000 successful regenerations without media replacement
  • Regeneration produces between 15 and to 30 gallons of EDC product daily, and no other waste streams
  • Recovered EDC product is used as feed at a local chemical plant

Media high capacity equals cost effectiveness

Synthetic media had been used for product recovery for decades, and to remediate solvent contaminated groundwater since the 1990’s, long before it was discovered that AMBERSORB™560 (AMBERSORB) has appreciable treatment capacity for 1,4-dioxane. ECT’s first synthetic media system, using a combination of AMBERLITE™ and AMBERSORB media, was installed in 1999 to remediate a 1,2-dichloroethane (1,2-DCA) spill at a large industrial site in Louisiana. 1,2-DCA has a much higher solubility than most volatile organic compounds (VOCs), is not readily stripped or oxidized and presents a unique challenge, especially at elevated influent concentrations. The Louisiana system is designed for influent concentrations averaging higher than 2,000 mg/l. (2,000,000 ug/l) with effluent treated to 5 ug/l, representing 6 orders of magnitude reduction. AMBERLITE was selected to do the “heavy lifting” due to its high capacity and cost effectiveness, with AMBERSORB used for final polishing of effluent.

The primary objective of the project was to use ECT’s synthetic media system to treat these very high 1,2-DCA concentrations in source area groundwater to non-detect levels (less than 5 µg/l). A pilot test was initiated to prove the process and fine tune the full-scale design. During the pilot test, the system was subjected to approximately 80 loading and regeneration cycles, demonstrating the capability of the polymeric (AMBERLITE) media to consistently treat influent 1,2-DCA concentrations from greater than 8,000 mg/l down to an average of 200 µg/l (0.2 mg/l). AMBERSORB was used to polish the 200 µg/l residual to non-detect, at less than 5 µg/l.