bioremediated, respectively. The highest specific growth rate observed was 0.15/
day.
2. Scenedesmus spp. are green algae (family Scenedesmaceae) commonly found in
freshwater. Scenedesmus spp. are used often related to phycoremediation studies
and also as a source of oil for biodiesel production. Ansari et al. (2019) reported
an interesting data on the application of Scenedesmus obliquus for municipal
wastewater phycoremediation and simultaneous production (w/w of dry weight)
of lipids (26), proteins (28), and carbohydrate (27). In addition, the authors
described an unusual economic analysis of wastewater phycoremediation. It is
worth noting that high specific growth rate of 0.42/day and phycoremediation
yields were obtained as 81% NH 4
+ , 100% NO 3
À , and 94% PO 4
3À . Infrared
spectroscopy analysis indicated functional groups as N-H, CH 3 , CH 2 , C¼O,
C-N, P¼O, and Si-O on the biomass surface—accumulation of biochemical
elements. When amortization, operating costs (including energy), and environmental benefits were taken into account, the net profit of phycoremediation was
16,885 US$/year.
3. Spirulina spp., in particular Spirulina platensis, can be used specifically for the
phytoremediation of waters polluted by toxic compounds. Compared to other
microalgae genera, Spirulina spp. have low generation time (fast biomass formation). Some specific metabolites of Spirulina spp. can induce heavy metals
complexion. Other interesting advantage of Spirulina spp. is easier biomass
separation from wastewater, since their vacuoles inflate (as aging), as a result
Spirulina spp. float (Adamia et al. 2018).
Adamia et al. (2018) applied Spirulina platensis for the bioremediation of 2,4,6trinitrotoluene—phycoremediation. The authors described that S. platensis adsorbed
%90% of 2,4,6-trinitrotoluene (22.5 ppm) during 15 days, in addition it was
observed that a relative low biomass accumulation decreases. The cultivation
parameters are illustrated in Table 4.1. The lag phase lasted 4 days, whereas the
log phase 13 days and the stationary phase 5 days (0.3 at 750 nm ). Thus, S. platensis is
an efficient and sustainable tool for the bioremediation of 2,4,6-trinitrotoluene.
Therefore, each microalga has an optimal growth rate, which should be related to
its specific wastewater. Thus, a correlation between yield of phycoremediation and
cultivation conditions is briefly described below (Table 4.1).
Since there is a wide structural diversity of microalgae species and also their
cultivation condition, regarding phycoremediation, some criteria should be taken
into account such as (a) growth rate, (b) key compounds removal rate, (c) cultivation
adaptation, and (d) biomass and/or bioproducts production rate (Arita et al. 2015;
Kesaano and Sims 2014). Phycoremediation should achieve removal rates higher as
56.5%, 68.5% and 90.6% of chemical organic demand, total nitrogen and phosphorus, respectively (Wang et al. 2010; Wang and Lan 2011). These nutrients (N and P)
are removed through assimilation; on the other hand, heavy metal removal is
performed through bioaccumulation and biosorption (Jais et al. 2017). Heavy metals
are successfully removed from wastewater by microalgae, since microalgae have a
wide range of polymers on their surface that are negatively charged (functional
4 Phycoremediation: A Sustainable Biorefinery Approach
107
day.
2. Scenedesmus spp. are green algae (family Scenedesmaceae) commonly found in
freshwater. Scenedesmus spp. are used often related to phycoremediation studies
and also as a source of oil for biodiesel production. Ansari et al. (2019) reported
an interesting data on the application of Scenedesmus obliquus for municipal
wastewater phycoremediation and simultaneous production (w/w of dry weight)
of lipids (26), proteins (28), and carbohydrate (27). In addition, the authors
described an unusual economic analysis of wastewater phycoremediation. It is
worth noting that high specific growth rate of 0.42/day and phycoremediation
yields were obtained as 81% NH 4
+ , 100% NO 3
À , and 94% PO 4
3À . Infrared
spectroscopy analysis indicated functional groups as N-H, CH 3 , CH 2 , C¼O,
C-N, P¼O, and Si-O on the biomass surface—accumulation of biochemical
elements. When amortization, operating costs (including energy), and environmental benefits were taken into account, the net profit of phycoremediation was
16,885 US$/year.
3. Spirulina spp., in particular Spirulina platensis, can be used specifically for the
phytoremediation of waters polluted by toxic compounds. Compared to other
microalgae genera, Spirulina spp. have low generation time (fast biomass formation). Some specific metabolites of Spirulina spp. can induce heavy metals
complexion. Other interesting advantage of Spirulina spp. is easier biomass
separation from wastewater, since their vacuoles inflate (as aging), as a result
Spirulina spp. float (Adamia et al. 2018).
Adamia et al. (2018) applied Spirulina platensis for the bioremediation of 2,4,6trinitrotoluene—phycoremediation. The authors described that S. platensis adsorbed
%90% of 2,4,6-trinitrotoluene (22.5 ppm) during 15 days, in addition it was
observed that a relative low biomass accumulation decreases. The cultivation
parameters are illustrated in Table 4.1. The lag phase lasted 4 days, whereas the
log phase 13 days and the stationary phase 5 days (0.3 at 750 nm ). Thus, S. platensis is
an efficient and sustainable tool for the bioremediation of 2,4,6-trinitrotoluene.
Therefore, each microalga has an optimal growth rate, which should be related to
its specific wastewater. Thus, a correlation between yield of phycoremediation and
cultivation conditions is briefly described below (Table 4.1).
Since there is a wide structural diversity of microalgae species and also their
cultivation condition, regarding phycoremediation, some criteria should be taken
into account such as (a) growth rate, (b) key compounds removal rate, (c) cultivation
adaptation, and (d) biomass and/or bioproducts production rate (Arita et al. 2015;
Kesaano and Sims 2014). Phycoremediation should achieve removal rates higher as
56.5%, 68.5% and 90.6% of chemical organic demand, total nitrogen and phosphorus, respectively (Wang et al. 2010; Wang and Lan 2011). These nutrients (N and P)
are removed through assimilation; on the other hand, heavy metal removal is
performed through bioaccumulation and biosorption (Jais et al. 2017). Heavy metals
are successfully removed from wastewater by microalgae, since microalgae have a
wide range of polymers on their surface that are negatively charged (functional
4 Phycoremediation: A Sustainable Biorefinery Approach
107