Page 171 - Materials Chemistry, Second Edition

152 Life Cycle Assessment of Wastewater Treatment

This single-step technique results in a compact process with high flexibility, which
can be fine-tuned for different biological applications. Recently, the removal of dif-
ferent trace organic pollutants employing a fungal MBR inoculated with a pure cul-
ture of T. versicolor has been tested, and the complete removal of bisphenol A and
diclofenac in sterile batch tests was reported (Yang et al., 2013).

8.6 PERSPECTIVES, DRAWBACKS, AND LIMITATIONS

The study of the fate of PhACs in the environment is still a fairly new topic.
PhACs are known as recalcitrant compounds, and the current WWTPs fail
to remove them effectively (Carballa et al., 2004). The concentration of these
compounds in marine ecosystems is increasing around the globe. The term bio-
pharmaceuticals refers to drugs produced by means other than direct extraction
from a natural source. Very few studies have been performed on these com-
pounds, as the product is often considered to be degraded quickly. Thus, the
environmental relevance of these compounds is not yet clear. The contamina-
tion potential of PhACs, along with their contribution to severe ecotoxicity and
human health problems, necessitates the development of cost-effective and effi-
cient methods for the elimination of PhACs from the environment (Prieto et al.,
2011; Asgher et al., 2008; Yang et al., 2013). The severity of the potential risks
of the PhACs to the ecosystem is dependent on the vulnerability of the con-
taminated ecosystem (Rodarte-Morales et al., 2012; Daughton and Ternes, 1999;
Kümmerer, 2008). Therefore, high-priority PhACs and vulnerable ecosystems
must be identified (Hester and Harrison, 2015).
It is believed that antibiotic resistance genes develop when bacteria are exposed
to sublethal doses of antibiotics. The presence of antibiotics in wastewater dis-
charges and the marine ecosystem is believed to be associated with the develop-
ment of these antibacterial-resistant pathogen bacteria. Bioremediation methods
based on the WRF and their oxidative enzymes are a green alternative to conven-
tional sewage sludge wastewater treatment technologies, and it appears that they
may achieve higher overall degradation yields of antibiotics than the conventional
technologies. Fungal treatment has been shown to be very promising in terms of the
removal of antibiotics in the influent. In addition, the successful use of WRF has
been reported for treating contaminated solid substrates. Treated sewage sludge that
is applied for land improvement must meet specific regulations for microbial patho-
gens and other classic pollutants before being used in land improvement applications
(Henry and Cole, 1997). However, the current regulations are mostly focused on the
reduction of pathogens and metals (Rodríguez-Rodríguez et al., 2012a; Fytili and
Zabaniotou, 2008). It is well known that pharmaceuticals can be accumulated in
sewage sludge in high concentrations. Legislation related to pharmaceuticals does
not exist (Rodríguez-Rodríguez et al., 2012a). Similar legislation must be developed
to address the safe content of pharmaceuticals in biosolids. WRF are promising
candidates for the removal of pharmaceuticals from sewage sludge, especially from
industrial or hospital WWTPs.
It is well known that molecules resulting from the parent compounds due to
structural change may have environmental relevance. The presence of structural