| Title: | Remediation of groundwater contaminated with MTBE and benzene: the potential of vertical-flow soil filter systems |
| Author(s): | van Afferden M; Rahman KZ; Mosig P; De Biase C; Thullner M; Oswald SE; Muller RA; |
| Address: | "Centre for Environmental Biotechnology (UBZ), UFZ-Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany. manfred.afferden@ufz.de" |
| DOI: | 10.1016/j.watres.2011.07.010 |
| ISSN/ISBN: | 1879-2448 (Electronic) 0043-1354 (Linking) |
| Abstract: | "Field investigations on the treatment of MTBE and benzene from contaminated groundwater in pilot or full-scale constructed wetlands are lacking hugely. The aim of this study was to develop a biological treatment technology that can be operated in an economic, reliable and robust mode over a long period of time. Two pilot-scale vertical-flow soil filter eco-technologies, a roughing filter (RF) and a polishing filter (PF) with plants (willows), were operated independently in a single-stage configuration and coupled together in a multi-stage (RF+PF) configuration to investigate the MTBE and benzene removal performances. Both filters were loaded with groundwater from a refinery site contaminated with MTBE and benzene as the main contaminants, with a mean concentration of 2970+/-816 and 13,966+/-1998 mug L(-1), respectively. Four different hydraulic loading rates (HLRs) with a stepwise increment of 60, 120, 240 and 480 L m(-2) d(-1) were applied over a period of 388 days in the single-stage operation. At the highest HLR of 480 L m(-2) d(-1), the mean concentrations of MTBE and benzene were found to be 550+/-133 and 65+/-123 mug L(-1) in the effluent of the RF. In the effluent of the PF system, respective mean MTBE and benzene concentrations of 49+/-77 and 0.5+/-0.2 mug L(-1) were obtained, which were well below the relevant MTBE and benzene limit values of 200 and 1 mug L(-1) for drinking water quality. But a dynamic fluctuation in the effluent MTBE concentration showed a lack of stability in regards to the increase in the measured values by nearly 10%, which were higher than the limit value. Therefore, both (RF+PF) filters were combined in a multi-stage configuration and the combined system proved to be more stable and effective with a highly efficient reduction of the MTBE and benzene concentrations in the effluent. Nearly 70% of MTBE and 98% of benzene were eliminated from the influent groundwater by the first vertical filter (RF) and the remaining amount was almost completely diminished ( approximately 100% reduction) after passing through the second filter (PF), with a mean MTBE and benzene concentration of 5+/-10 and 0.6+/-0.2 mug L(-1) in the final effluent. The emission rate of volatile organic compounds mass into the air from the systems was less than 1% of the inflow mass loading rate. The results obtained in this study not only demonstrate the feasibility of vertical-flow soil filter systems for treating groundwater contaminated with MTBE and benzene, but can also be considered a major step forward towards their application under full-scale conditions for commercial purposes in the oil and gas industries" |
| Keywords: | "Benzene/*isolation & purification Environmental Restoration and Remediation/*methods Filtration/*methods Methyl Ethers/*isolation & purification *Soil Water Pollutants, Chemical/*isolation & purification;" |
| Notes: | "Medlinevan Afferden, Manfred Rahman, Khaja Z Mosig, Peter De Biase, Cecilia Thullner, Martin Oswald, Sascha E Muller, Roland A eng Research Support, Non-U.S. Gov't England 2011/07/29 Water Res. 2011 Oct 15; 45(16):5063-74. doi: 10.1016/j.watres.2011.07.010. Epub 2011 Jul 14" |
