(Rastogi 2016; Aydiner et al. 2016; Raghavarao et al. 2005;
Petrotos et al. 2010).
Rastogi (2016) presented a high-quality review which is
possible to obtain high quantity of relevance information.
They exposed the necessity of their paper because of its
novel features, which include the concentration of liquid
foods at ambient temperature and pressure without significant fouling of membrane. Therefore, they exposed that the
characteristics explained made the technology commercially
attractive. They explain that the asymmetric membrane used
for FO poses newer challenges to account both external and
internal concentration polarizations leading to significant
reduction in water flux. They concluded that FO is an
emerging technology for water recovery from liquids due to
its novel features, which include no use of solvent for
extraction, low energy consumption, higher retention of
thermolabile components and attainment of higher concentration. Furthermore, recovery and regeneration of draw
solution is a future challenge to achieve by the scientific
community to scale up forward osmosis in food industry.
Dairy wastewater management is a potential area in
which many improvements can be gotten by implementing
membrane processes. In this sense, Aydiner et al. (2016)
presented an hierarchical prioritization of innovative treatment systems which consist of multiple criteria decision
making. In their study, four innovative systems—which
include membrane distillation, FO, nanofiltration and RO—
are compared to a traditional system in terms of hierarchically prioritized for environmentally benign treatment.
Despite the existence of both greatest importance of energy
consumption and higher energy requirements of novel
solutions, major prominent features to be provided by
real-scale applications of innovative systems were determined as more valuable multiple outcomes in environmental
protection and economic profit. They concluded that sustainable dairy wastewater management in a more desirable
manner than now could be accomplished by means of
technically highly efficient, economically cost-effective and
environmentally eco-innovative achievements by membrane
technology employment.
With liquid foods, we refer to fruit juices and natural
colors. These compounds have gained importance during the
last years in food industry due to the high number of beneficial components for human health. Fruit juices and natural
colors are extracted with a low solid content which inevitably suppose a high water consumption. Therefore a concentration stage previous its commercialization is obligatory.
For this reason, Raghavarao et al. (2005) proposed an
interesting review of the different available techniques for
concentrating liquid foods. Concentrating liquid foods provides a reduction in transport, packaging and storage costs.
Both fruit and natural juices are sensitive to temperature
changes hence process which work at ambient temperature
are needed. In this sense, in their review these authors
exposed the importance of membrane processes since one of
its best characteristics is the operation at around 25–30 °C.
They explain how important is concentration by using
membranes such as ultrafiltration, nanofiltration, reverse
osmosis and forward osmosis for the concentration of liquid
foods (fruit juices and colors).
In the case of Petrotos et al. (2010), an investigation to
concentrate tomato juice was developed by FO application.
They designed a novel membrane module which consists of
a stainless steel flat module in which it can distinguish two
parts of a square flange screwed and a piece of flat membrane between them. The configuration resulted in the formation of two chambers of special morphology which
allowed the flow of tomato juice and osmotic medium in the
two respective sides of the membrane and enabled the
osmotic transfer of pure water from the juice to the osmotic
medium side. By employing sodium chloride as draw solution, tomato juice was concentrated from 5.5°Brix to 16°
Brix, achieving the standard levels of commercial available
tomato sauces. To re-concentrate the post-diluted draw
solution, electrodialysis is proposed as a viable alternative to
the commonly used evaporative process. As main conclusion, these authors affirmed that the use of NaCl brines as
osmotic media in a combined FO–electrodialysis process
operated at ambient temperature and low pressure allows to
produce tomato concentrates of commercial interest (Fig. 8).
4.4 Pharmaceutical Industry
A high value-added industry with high economic benefits
when applying novel low-energy technologies is pharmaceutical industry. In this sense, FO along with other membrane processes is suitable technologies to apply in this
industry and many researchers have developed astounding
applications (Yang et al. 2009; Wang et al. 2011; Xie et al.
2012; Jin et al. 2012; Cui and Chung 2018).
First, Yang et al. (2009) started an important way in the
field of pharmaceutical by demonstrating the prospect
of
dual-layer
polybenzimidazole–polyethersulfone/
polyvinylpyrrolidone hollow fiber nanofiltration membranes. They built the dual-layer hollow fiber membrane via
extrusion technology that has an ultra-thin selective skin
around 10 lm, fully open-cell water channels underneath
and a microporous sponge-like support structure. Afterward,
experimental results show that the newly developed
dual-layer hollow fiber nanofiltration membrane can achieve
a high throughput for lysozyme enrichment and less protein
fouling when using it as a FO membrane. In addition, the
high divalent salt rejection toward Mg
2+ at around 90% of
this dual-layer membrane ensures the enriched lysozyme
product with high purity and without change and denaturing.
8
M. Rodríguez-Galán et al.
Petrotos et al. 2010).
Rastogi (2016) presented a high-quality review which is
possible to obtain high quantity of relevance information.
They exposed the necessity of their paper because of its
novel features, which include the concentration of liquid
foods at ambient temperature and pressure without significant fouling of membrane. Therefore, they exposed that the
characteristics explained made the technology commercially
attractive. They explain that the asymmetric membrane used
for FO poses newer challenges to account both external and
internal concentration polarizations leading to significant
reduction in water flux. They concluded that FO is an
emerging technology for water recovery from liquids due to
its novel features, which include no use of solvent for
extraction, low energy consumption, higher retention of
thermolabile components and attainment of higher concentration. Furthermore, recovery and regeneration of draw
solution is a future challenge to achieve by the scientific
community to scale up forward osmosis in food industry.
Dairy wastewater management is a potential area in
which many improvements can be gotten by implementing
membrane processes. In this sense, Aydiner et al. (2016)
presented an hierarchical prioritization of innovative treatment systems which consist of multiple criteria decision
making. In their study, four innovative systems—which
include membrane distillation, FO, nanofiltration and RO—
are compared to a traditional system in terms of hierarchically prioritized for environmentally benign treatment.
Despite the existence of both greatest importance of energy
consumption and higher energy requirements of novel
solutions, major prominent features to be provided by
real-scale applications of innovative systems were determined as more valuable multiple outcomes in environmental
protection and economic profit. They concluded that sustainable dairy wastewater management in a more desirable
manner than now could be accomplished by means of
technically highly efficient, economically cost-effective and
environmentally eco-innovative achievements by membrane
technology employment.
With liquid foods, we refer to fruit juices and natural
colors. These compounds have gained importance during the
last years in food industry due to the high number of beneficial components for human health. Fruit juices and natural
colors are extracted with a low solid content which inevitably suppose a high water consumption. Therefore a concentration stage previous its commercialization is obligatory.
For this reason, Raghavarao et al. (2005) proposed an
interesting review of the different available techniques for
concentrating liquid foods. Concentrating liquid foods provides a reduction in transport, packaging and storage costs.
Both fruit and natural juices are sensitive to temperature
changes hence process which work at ambient temperature
are needed. In this sense, in their review these authors
exposed the importance of membrane processes since one of
its best characteristics is the operation at around 25–30 °C.
They explain how important is concentration by using
membranes such as ultrafiltration, nanofiltration, reverse
osmosis and forward osmosis for the concentration of liquid
foods (fruit juices and colors).
In the case of Petrotos et al. (2010), an investigation to
concentrate tomato juice was developed by FO application.
They designed a novel membrane module which consists of
a stainless steel flat module in which it can distinguish two
parts of a square flange screwed and a piece of flat membrane between them. The configuration resulted in the formation of two chambers of special morphology which
allowed the flow of tomato juice and osmotic medium in the
two respective sides of the membrane and enabled the
osmotic transfer of pure water from the juice to the osmotic
medium side. By employing sodium chloride as draw solution, tomato juice was concentrated from 5.5°Brix to 16°
Brix, achieving the standard levels of commercial available
tomato sauces. To re-concentrate the post-diluted draw
solution, electrodialysis is proposed as a viable alternative to
the commonly used evaporative process. As main conclusion, these authors affirmed that the use of NaCl brines as
osmotic media in a combined FO–electrodialysis process
operated at ambient temperature and low pressure allows to
produce tomato concentrates of commercial interest (Fig. 8).
4.4 Pharmaceutical Industry
A high value-added industry with high economic benefits
when applying novel low-energy technologies is pharmaceutical industry. In this sense, FO along with other membrane processes is suitable technologies to apply in this
industry and many researchers have developed astounding
applications (Yang et al. 2009; Wang et al. 2011; Xie et al.
2012; Jin et al. 2012; Cui and Chung 2018).
First, Yang et al. (2009) started an important way in the
field of pharmaceutical by demonstrating the prospect
of
dual-layer
polybenzimidazole–polyethersulfone/
polyvinylpyrrolidone hollow fiber nanofiltration membranes. They built the dual-layer hollow fiber membrane via
extrusion technology that has an ultra-thin selective skin
around 10 lm, fully open-cell water channels underneath
and a microporous sponge-like support structure. Afterward,
experimental results show that the newly developed
dual-layer hollow fiber nanofiltration membrane can achieve
a high throughput for lysozyme enrichment and less protein
fouling when using it as a FO membrane. In addition, the
high divalent salt rejection toward Mg
2+ at around 90% of
this dual-layer membrane ensures the enriched lysozyme
product with high purity and without change and denaturing.
8
M. Rodríguez-Galán et al.