Environmental Engineering Reference
In-Depth Information
fronds and dry mass of Lemna minor (Casieri et al.
2008
). Cytotoxicity and
genotoxicity have been evaluated using Allium cepa root cells (Carita and Marin-
Morales
2008
; Jadhav et al.
2011
; Phugare et al.
2011
). Microbial toxicity has been
analysed using Kocuria rosea, P. aerugenosa, Azotobacter vinelandii (Parshetti
et al.
2010
), Sphingomonas paucimobilis (Ayed et al.
2011
), Vibrio
scheri (Gar-
cia-Montano et al.
2008
; Anastasi et al.
2011
), Sinorhizobium meliloti (Enayati-
zamir et al.
2011
), P. putida (Bohmer et al.
2010
), Sinorhizobium meliloti
(Enayatizamir et al.
2011
), P. vulgaris, Rhizobium radiobacter, Acinetobacter sp.,
Pseudomonas desmolyticum, Cellulomonas biazotea, Escherichia coli and Micro-
coccus glutamicus (Saratale et al.
2009
,
2010
) or by the inhibition of cellular
growth of the green unicellular alga Pseudokirchneriella subcapitata (Anastasi
et al.
2011
). The oxidative stress response is a newly studied parameter for the
assessment of the toxic effects caused by textile ef
uents. Reactive oxygen species
(ROS) are chemically reactive molecules containing oxygen, which include the
superoxide anion (O
2
−
), H
2
O
2
and the hydroxyl radical (OH
). These molecules are
by-products of the partial reduction of oxygen metabolism, and they play a crucial
role in cell signaling and development in plants, including the plant defence
response, cell death and oxidative stress. However, ROS can also cause protein,
lipid and DNA damage. Plant systems possess defence mechanisms against such
oxidative stress, which are composed of antioxidants or scavenging enzymes, such
as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX),
glutathione reductase and peroxiredoxins (Jadhav et al.
2011
). Thus, the analysis of
oxidative stress must include the analysis of these antioxidant enzymes, lipid per-
oxidation and protein oxidation. Allium cepa root cells have been used to carry out
this type of analysis (Jadhav et al.
2011
; Phugare et al.
2011
). The same model has
also been used to study chromosomal aberration and cell division (Phugare et al.
2011
). The most employed, well-established and standardized acute lethality test
uses Daphnia magna (Elisangela et al.
2009
; Porri et al.
2011
; Rizzo
2011
).
·
6 Future Prospectives
The treatment of textile wastewater has become a great challenge over the past
decades. Till recently, there is no single and economically attractive treatment
method that can effectively decolorize and detoxify the textile wastewater. As
regulations have become more stringent, companies are forced to use more tech-
nologically sophisticated methods. There is also a concomitant increase in cost for
waste management that many companies may not be able to handle. Thus, effective
wastewater treatment is not the only problem, but reductions in the waste and the
reuse of water are also necessary. It is of the most importance to develop effective,
accessible, cheap and environmentally friendly treatment processes. Taking into
consideration the advances in this
eld, we believe that future research activities
should focus on four principal areas: (a) achieve dye mineralization in addition to
decoloration. This idea is very important because an additional problem with
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