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| Titel |
Impact of peatland restoration on water treatability |
| VerfasserIn |
Stuart Rae, Bart van Dongen, Clare Robinson, Stephen Boult |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250079566
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| Zusammenfassung |
| The design of catchment management practices for upland peat to optimise runoff quantity
and quality has been a focus of research for many years. This has been necessary because
these catchments are often used for drinking water collection. However, because of more
recent concerns about the greenhouse gas (GHG) potential of CO2 and CH4 emissions peat
management practices may also be required to maintain or enhance immobilisation of organic
carbon (OC). Â
With respect to both GHG emissions and drinking water quality the most significant
component of runoff is OC and research has, therefore, focussed on understanding what
controls variability in its mass flux. However, in both cases the size and chemical
composition of the OC may be as, or more, important than the amount. These characteristics
will control the lability of the OC – the rate at which solid OC is converted to GHG – and also
the ease with which the treatment process can make runoff potable.
Pristine sphagnum covered peat and eroded bare peat are end members of catchment
cover resulting from historic changes in air quality – pollutant inputs – and land management
practices. They are also the likely end members under future environmental changes such as
climatic warming, alterations in rainfall regime and the land management practices selected
to minimise GHG emissions.
This work compares the particle size distribution and chemical composition of OC in
runoff from simulations of sphagnum covered and bare peat. Furthermore, the influence of
the OC, and of < μm size fractions of the OC, on a critical part of the water treatment
process; the flocculation of Fe(OH)3 are assessed.
The PSD of OC from sphagnum was much smaller than that from bare peat. The
former was predominantly carbohydrate whilst the latter was phenolic suggesting
the former would be more labile. For sphagnum covered peat runoff flocculation
of Fe(OH)3 was prevented at concentrations from 20 to as low as 5 mg/l (OC).
However, the runoff from areas of bare peat was able to prevent flocculation at
concentrations as low as 1 mg/l (OC). (Investigations at lower concentrations are ongoing). |
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