factors, which directly affect the dewatering efficacy in sludge (Houghton et al.
2001; Houghton and Stephenson 2002; More et al. 2010). Similarly, these EPSs are
used as bioflocculant materials in dewatering of sludge. One of the studies reveals
that EPS obtained from the bacteria Klebsiella sp. showed sludge dewatering
efficiency similar to chemical flocculant such as alum at particular concentrations
(Yang et al. 2012). Similarly, Zhang et al. (2010) reported that at 0.17% (w/w)
concentration of P. mirabilis with the combination of 1.3% (w/w), CaCl 2 will
increase the sludge dewatering efficacy. These combination and conditions worked
out well at neutral pH (7–7.5). As of now, very few scientific reports are available,
and it needs to explore detailed investigations on EPS in sludge dewatering process
in the near future.
2.7 Removal of Toxic Organic Compounds
Several studies and scientific reports show the role of exopolysaccharides (EPS) in
removal of various organic pollutants from wastewater, sludge, and contaminated
site. In particular, degradation of polycyclic aromatic hydrocarbons (PAHs), bioremediation by using microorganisms (Zhang et al. 2011). Several EPS-producing
bacterial species were applied to remove PAHs from contaminated soils (Jia et al.
2011; Zhang et al. 2011). When we applied EPS to the contaminated site, the
interaction of EPS and PAHs, mostly exothermic hydrophobic interactions, take
place. In situ application of PAHs, degrading bacteria species with EPS-producing
potential will increase their degradation efficacy of PAHs (Zhang et al. 2011).
Similarly, Liu et al. (2001) studied EPS-producing bacteria species that, increase
the release of soil-bound phenanthrene. Jia et al. (2011) reported that Zoogloea
sp. and Aspergillus niger showed more than 30% of pyrene degradation potential
after 35 days, the rate of pyrene degradation increased with increase in EPS
concentration as well as increased specific surface area of the EPS (Fig. 7.4).
Fig. 7.4 Interaction
mechanisms for the
processes of elimination of
organic pollutants
144
P. Muthukumaran et al.
2001; Houghton and Stephenson 2002; More et al. 2010). Similarly, these EPSs are
used as bioflocculant materials in dewatering of sludge. One of the studies reveals
that EPS obtained from the bacteria Klebsiella sp. showed sludge dewatering
efficiency similar to chemical flocculant such as alum at particular concentrations
(Yang et al. 2012). Similarly, Zhang et al. (2010) reported that at 0.17% (w/w)
concentration of P. mirabilis with the combination of 1.3% (w/w), CaCl 2 will
increase the sludge dewatering efficacy. These combination and conditions worked
out well at neutral pH (7–7.5). As of now, very few scientific reports are available,
and it needs to explore detailed investigations on EPS in sludge dewatering process
in the near future.
2.7 Removal of Toxic Organic Compounds
Several studies and scientific reports show the role of exopolysaccharides (EPS) in
removal of various organic pollutants from wastewater, sludge, and contaminated
site. In particular, degradation of polycyclic aromatic hydrocarbons (PAHs), bioremediation by using microorganisms (Zhang et al. 2011). Several EPS-producing
bacterial species were applied to remove PAHs from contaminated soils (Jia et al.
2011; Zhang et al. 2011). When we applied EPS to the contaminated site, the
interaction of EPS and PAHs, mostly exothermic hydrophobic interactions, take
place. In situ application of PAHs, degrading bacteria species with EPS-producing
potential will increase their degradation efficacy of PAHs (Zhang et al. 2011).
Similarly, Liu et al. (2001) studied EPS-producing bacteria species that, increase
the release of soil-bound phenanthrene. Jia et al. (2011) reported that Zoogloea
sp. and Aspergillus niger showed more than 30% of pyrene degradation potential
after 35 days, the rate of pyrene degradation increased with increase in EPS
concentration as well as increased specific surface area of the EPS (Fig. 7.4).
Fig. 7.4 Interaction
mechanisms for the
processes of elimination of
organic pollutants
144
P. Muthukumaran et al.