Geoscience Reference
In-Depth Information
in the marine and freshwater fields. For example, Lapworth et al. (
2009
) investigated
hyphoreic transformations of dissolved, colloidal, and particulate organic matter using
fluorescence EEMs.
3.4.3 Groundwater Anthropogenic Organic Matter Characteristics
Contaminated groundwaters might be expected to comprise the same fluorescence EEM
characteristics of the pollutant source that has undergone dilution and chemical and micro-
bial processing in the aquifer. Almost certainly, a wider range of contaminant fluorescent
signatures exist than those reported. The two reported contaminant fluorescence organic
matter characteristics are:
1.
Unusually intense peak T and/or peak B fluorescence, derived from organic effluents.
For example, Lapworth et al. (
2008
) report high peak T intensities at a groundwater
site that had historically undergone surface slurry applications.
2.
A specific fluorescence peak at excitation 220-230 nm and emission between 340-
370 nm, which is particularly intense and derived from landfill leachates. First reported
in contaminated Missouri spring waters, Baker and Curry (
2004
) demonstrated a strong
correlation between the intensity of this peak and geochemical parameters such as
BOD and ammonia concentration, and postulated that it was derived from one or more
polycyclic aromatic hydrocarbons present in the landfill leachate.
International peer review published applications of the use of fluorescence to detect ground-
water organic matter pollution are not widespread. In the authors' experience, this reflects
a greater amount of work undertaken in a consultancy setting. Given the increasing global
interest in water recycling, including aquifer recharge schemes, future research might be
expected to investigate the movement and transformation of recycled water within ground-
water aquifers.
3.5 Fluorescence of Wastewater and Drinking Water
3.5.1 Wastewater Fluorescence
Despite the substantial body of literature that is concerned with the fluorescence and
spectral properties of dissolved organic matter in marine, terrestrial, and fluvial environ-
ments, much less attention has been given to the investigation of these properties in rela-
tion to wastewaters. The generic term wastewater encompasses any water body that has
been impacted by anthropogenic influence, so as to adversely affect the overall quality.
Wastewater can comprise liquid waste discharged by residential, commercial, and industrial
properties (including agriculture), and by definition incorporates a wide range of potential
chemical contaminants at varying concentrations. Most commonly the term wastewater
refers to municipal wastewater containing a broad mix of contaminants from a variety of
wastewaters from different sources. Sewage is a subset of wastewater, referring to waste
