From full-scale biofilters to bioreactors: engineering biological metaldehyde removal
| Autor: | Bruce Jefferson, Francis Hassard, Adam Brookes, Gregg Iceton, Raffaella Villa, Catherine Rolph, Andoni Choya |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Environmental Engineering
010504 meteorology & atmospheric sciences Acetaldehyde 010501 environmental sciences acclimation 01 natural sciences Slow sand filter law.invention Water Purification chemistry.chemical_compound Bioreactors law Bioreactor Environmental Chemistry metaldehyde Waste Management and Disposal Filtration 0105 earth and related environmental sciences Pollutant fluidised-bed reactor Chemistry micropollutant removal Drinking Water slow-sand filter Sorption Fluidised-bed reactor Biodegradation Pollution Biodegradation Environmental Environmental chemistry Biofilter Metaldehyde Water Pollutants Chemical |
| ISSN: | 0048-9697 |
| Popis: | The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Polar, low molecular weight pesticides such as metaldehyde are challenging and costly to remove from drinking water using conventional treatment methods. Although biological treatments can be effective at treating micropollutants, through biodegradation and sorption processes, only some operational biofilters have shown the ability to remove metaldehyde. As sorption plays a minor role for such polar organic micropollutants, biodegradation is therefore likely to be the main removal pathway. Here, the biodegradation of metaldehyde was monitored, and assessed, in an operational slow sand filter. Long-term data showed that metaldehyde degradation improved when inlet concentrations increased. A comparison of inactive and active sand batch reactors showed that metaldehyde removal happened mainly through biodegradation and that the removal rates were greater after the biofilm was acclimated through exposure to high metaldehyde concentrations. This suggested that metaldehyde removal was reliant on enrichment and that the process could be engineered to decrease treatment times (from days to hours). Through-flow experiments using fluidised bed reactors, showed the same behaviour following metaldehyde acclimation. A 40% increase in metaldehyde removal was observed in acclimated compared with non-acclimated columns. This increase was sustained for more than 40 days, achieving an average of 80% removal and compliance (< 0.1 µ L-1) for more than 20 days. An initial microbial analysis of the acclimated and non-acclimated biofilm from the same filter materials, showed that the microbial community in acclimated sand was significantly different. This work presents a novel conceptual template for a faster, chemical free, low cost, biological treatment of metaldehyde and other polar pollutants in drinking water. In addition, this is the first study to report kinetics of metaldehyde degradation in an active microbial biofilm at a WTW. |
| Databáze: | OpenAIRE |
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