Page 160 - Materials Chemistry, Second Edition

Fungal Treatment of Pharmaceuticals in Effluents 141

based on the white-rot fungi and their oxidative enzymes (Rodarte-Morales et al.,
2012). The complete removal of some recalcitrant PhACs, including fragrances (i.e.,
galaxolide and tonalide), tranquilizers (i.e., diazepam), carbamazepine, and clofibric
acid has been reported based on conventional treatments (Doll and Frimmel, 2004).
However, the overall degradation of anti-epileptics (i.e., carbamazepine) and the main
anti-inflammatory compounds has been reported to range from 10% to 70% in the lit-
erature (Rodarte-Morales et al., 2012; Carballa et al., 2004; Ikehata et al., 2006). The
other drawback of conventional methods is the formation of undesirable and often
toxic transformation products (Cruz-Morató et al., 2013). On the other hand, higher
or complete removal (degradation) of anti-inflammatory compounds is reported for
the advanced technologies; that is, up to 100% removal of naproxen (NPX) by ozone
treatment and 80%–100% for ibuprofen (IBP) by the photo-Fenton system (Rodarte-
Morales et al., 2012). These systems often fail at effectively removing other PhACs
(partial removal of 50%–70%) (Gagnon et al., 2008; Mendez-Arriaga et al., 2010).
In addition, the implementation of ozonation treatment, for example, is still far from
being economical, which makes this method unfeasible (Ternes et al., 2003). MBR
and activated carbon–based methods are also expensive methods, which are effective
in the removal of some PhACs but fail to remove others (Snyder et al., 2007).
The other emerging alternative treatment of pharmaceutical compounds in
WWTP effluent is a biological method based on the employment of bioremediation
techniques. Bioremediation is an attractive alternative technique, which employs the
metabolic potential of biological agents such as fungi to remove contaminants from
soil or water (Keharia and Madamwar, 2003). Recently, the use of white-rot fungi
(WRF) for the effective removal of pharmaceuticals from wastewater has attracted
attention. WRF are capable of degrading lignin, dyes, polycyclic aromatic hydrocar-
bons (PAHs), and several PhACs with degradation of up to 100% employing their
nonspecific enzymatic system, including extracellular lignin-modifying enzymes
and intracellular enzymes (Rodarte-Morales et al., 2012; Wesenberg et al., 2003;
Field et al., 1992; Asgher et al., 2008; Prieto et al., 2011).

8.2 PHARMACEUTICS AND PHARMACEUTICAL
COMPONENTS IN EFFLUENTS
8.2.1 poTenTial sources of pHarMaceuTical
polluTanTs in THe environMenT
Persistent organic pollutants (POPs) are toxic substances that can be released into
the environment by the application of agrochemicals in agricultural areas, through
agroindustry applications, or by the application of biosolids for soil improvement.
Agrochemicals are chemicals used in agriculture, such as pesticides or fertilizers.
Huge agro-industrial processes, including oil extraction procedures, bleaching (i.e.,
of cotton for the pulp and paper industries), and distilleries, produce several billion
liters annually of colored and toxic effluents, often rich in persistent compounds
(i.e., phenol compounds, chlorinated lignin, and dyes), which are a potential risk to
the environment (Adhoum and Monser, 2004; Pokhrel and Viraraghavan, 2004).
Another source of persistent pollutants in agricultural practice is the employment