Geoscience Reference
In-Depth Information
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Excitation Wavelength (nm)
Figure 3.15. Excitation-emission matrices of waters at different water treatment stages.
(a)
Raw water
(b) Clarified water. (Adapted from Bieroza,
2009
, with permission from Elsevier.) (See Plate 8.)
DOM related to natural systems is derived predominantly from plant material and where
microbial activity is slow and weak but nevertheless sustained. The unique origins of
wastewater DOM are highlighted in their associated EEMs, which are most notably dif-
ferent from EEMs of DOM from marine and freshwater systems, where peak C predomi-
nates (Hudson et al.,
2007
). The unique spectral characteristics of wastewater DOM have
facilitated the tracking of sewage contamination in aquatic systems (Galapate et al.,
1998
;
Baker,
2001
; Baker et al.,
2003
,
2005
; Chen et al.,
2003
; Holbrook et al.,
2005
; Hudson
et al.,
2008
; Carstea,
2010
).
The intense fluorescence intensity associated with sewage-derived DOM has led to the
investigation of fluorescence as a marker for existing biochemical and chemical parameters
commonly used to determine wastewater quality and monitor wastewater treatment pro-
cesses (Reynolds and Ahmad,
1997
; Ahmad and Reynolds,
1999
; Reynolds,
2002
;Vasel
and Praet,
2002
; Lee and Ahn,
2004
; Cumberland and Baker,
2007
; Hudson et al.,
2008
;
Hur et al.,
2008
). Relationships between the fluorescence intensity of various peaks (A, B,
T, and C) and water quality parameters have been investigated. The most common wastewa-
ter quality parameters investigated include the 5-day BOD; COD of filtered and unfiltered
