Page 167 - Materials Chemistry, Second Edition

148 Life Cycle Assessment of Wastewater Treatment

the source of water, and metabolites, as well as the probable interactions between
different interfering compounds in the medium (Comerton et al., 2009). Although
the standard methodologies are well established with standard protocols for analyz-
ing the “classic” contaminations, nevertheless, the need for standardized analytical
methods exists for trace concentrations of less characterized emerging pharmaceuti-
cals, especially for compounds with greater polarities, which may have toxicological
relevance (Snyder et al., 2003). Different direct and indirect analytical methods have
been applied for quantification of PhACs and their degradation products in water or
polluted soil. Indirect analytical methods involve an extraction procedure (i.e., solid-
phase extraction) followed by instrumental analyses.
Different methods have been employed for the extraction of the analyte, including
solid-phase extraction and solvent extraction methods, which have been described
elsewhere (Rodríguez-Rodríguez et al., 2011, 2012; Marco-Urrea et al., 2009).
Several instrumental analyses employed for the determination and quantification of
PhAC concentration in the effluent after fungal treatment include gas chromatog-
raphy coupled with mass spectrometric detection, gas chromatography combustion
isotope ratio mass spectrometry (GC-CIRMS), high performance liquid chromatog-
raphy (HPLC) coupled with UV detector or mass spectrometric detection, ultra-
performance liquid chromatography (UPLC), HPLC with diode-array detection
(HPLC-DAD), liquid chromatography/electrospray ionization tandem mass spec-
trometry (LC-ESI-QqQ–MS/MS), nuclear magnetic resonance (NMR) analysis, and
a combination of techniques (Marco-Urrea et al., 2009; Snyder et al., 2003; Cruz-
Morató et al., 2013; Prieto et al., 2011; Marco-Urrea et al., 2010a). Enzyme activity
represents the quantity of the available active enzyme and is measured in enzyme
units (U). One unit of enzyme is defined as the amount of enzyme with enzymatic
activity capable of catalyzing the conversion of 1 µmol of the substrate per min
at a specific temperature (Cajthaml et al., 2009). Enzymatic activities of different
enzymes, including MnP, LiP, and laccase, are often measured based on established
protocols (Camarero et al., 1999; Rodarte-Morales et al., 2012; Yang et al., 2013;
Tien and Kirk, 1988; Zhang and Geißen, 2012).
The toxicity of the medium is often measured by the Photobacterium phos-
phoreum luminescence reduction test (Microtox test). In this method, the biolu-
minescent bacterium Vibrio fischeri, which liberates energy in the form of visible
light, is employed for the determination of toxicity. Toxic compounds disrupt the
respiratory process of the bacteria, leading to a reduction in the light output. The
change in luminescence is proportional to the percentage inhibition of Vibrio
fischeri and can be directly correlated to toxicity. Microtox tests can be employed
for measuring the toxicity of both solid-phase and aqueous substances for chronic
or acute toxicity testing (Marco-Urrea et al., 2009; ISO, 2007;Cruz-Morató et al.,
2013). The toxicity of sewage sludge or a biosolid can also be measured employ-
ing the seed germination toxicity test. In this test, the phytotoxicity of the solid
sample is evaluated by seed germination, in which the germination percentage
and root length of different incubated seeds are measured and compared with
the germination percentage and root length of the same seeds incubated with
distilled water for an identical period of time at the same temperature (Rodríguez-
Rodríguez et al., 2011).