Treatment of volatile organic contaminants in a vertical flow filter: Relevance of different removal processes
| Autor: | Daniel Reger, Paula M. Martínez-Lavanchy, Nils Reiche, Cecilia De Biase, Uli Maier, Sascha E. Oswald, Manfred van Afferden, Sven Jechalke, Martin Thullner, Mònica Rosell, Axel Schmidt |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Institut für Erd- und Umweltwissenschaften
Environmental Engineering Aardwetenschappen MTBE 0207 environmental engineering 02 engineering and technology 010501 environmental sciences Management Monitoring Policy and Law 01 natural sciences Organic compound chemistry.chemical_compound TRACER Numerical modeling Tracers 020701 environmental engineering Benzene 0105 earth and related environmental sciences Nature and Landscape Conservation SAFIRA II chemistry.chemical_classification Volatilisation VOCs Biodegradation Contamination Stable isotope fractionation analysis 6. Clean water Catabolic genes chemistry Radon 13. Climate action Environmental chemistry Sewage treatment Volatilization Groundwater |
| Zdroj: | Ecological Engineering Ecological Engineering, 37(9), 1292. Elsevier |
| ISSN: | 0925-8574 |
| DOI: | 10.1016/j.ecoleng.2011.03.023 |
| Popis: | Vertical flow filters and vertical flow constructed wetlands are established wastewater treatment systems and have also been proposed for the treatment of contaminated groundwater. This study investigates the removal processes of volatile organic compounds in a pilot-scale vertical flow filter. The filter is intermittently irrigated with contaminated groundwater containing benzene, MTBE and ammonium as the main contaminants. The system is characterized by unsaturated conditions and high contaminant removal efficiency. The aim of the present study is to evaluate the contribution of biodegradation and volatilization to the overall removal of benzene and MTBE. Tracer tests and flow rate measurements showed a highly transient flow and heterogeneous transport regime. Radon-222, naturally occurring in the treated groundwater, was used as a gas tracer and indicated a high volatilization potential. Radon-222 behavior was reproduced by numerical simulations and extrapolated for benzene and MTBE, and indicated these compounds also have a high volatilization potential. In contrast, passive sampler measurements on top of the filter detected only low benzene and MTBE concentrations. Biodegradation potential was evaluated by the analysis of catabolic genes involved in organic compound degradation and a quantitative estimation of biodegradation was derived from stable isotope fractionation analysis. Results suggest that despite the high volatilization potential, biodegradation is the predominant mass removal process in the filter system, which indicates that the volatilized fraction of the contaminants is still subject to subsequent biodegradation. In particular, the upper filter layer located between the injection tubes and the surface of the system might also contribute to biodegradation, and might play a crucial role in avoiding the emission of volatilized contaminants into the atmosphere. |
| Databáze: | OpenAIRE |
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