of recovery factor. Both MD and MCr could be implemented
in the industrial wastewater treatment consisting high
Na 2 SO 4 . Direct treatment using unfiltered wastewater might
be more suitable for these both technologies compared to
NF-treated wastewater (Quist-Jensen et al. 2017).
3.2 Electrical-Driven
Most of the materials will involve with the electrical charge
when dispersed in polar media. The charge properties of
the ions involved could be a driven factor for the separation process. So, separation rate of the colloids or fine
particles will depend on the surface charge of those particles. Therefore, in membrane technology, the separation
process by the electrically-driven membrane was occurred
due to the alternate ion exchange membranes. There are
two main ED membranes in separation field, cation
exchange membrane (CEM) and anion exchange membrane
(AEM) where the positive charged ions and negative
charged are transported selectively depend on the which
type of the membrane used. The ED processes are potentially feasible for the (partial) desalination of high salinity
waters including PW.
There are several ED-related processes are involved for
treatment of FPW consisting reverse electrodeionization
(REDI) (i.e., the combination of EDI and reverse electrodialysis (RED)) (Lopez et al. 2016), electrodeionization
(EDI), (CDI), ion-concentration polarization desalination
(ICP) (Kwak et al. 2016) and membrane capacitive deionization. A typical EDI unit has same configuration with the
ED, but at least one channel is filled with ion exchange resin.
Contrary to ED, which uses energy to remove salts, RED is a
membrane-based process that producing electricity by mixing two solutions at different concentrations [225]. Lopez
et al. (2016) state that the incorporating ion exchange wafers
in each cell could enhance the REDI performance in order to
shorten the passage ways for the diffusion process and limit
the shadow spacer effect. As compared to a conventional ED
system, a degree of enhanced ion selectivity occurred by
increasing the wafer size and varying the wafer
compositions.
Capacitive deionization (CDI) is a desalination process in
which an electrical energy is used to high surface area
electrodes in order to adsorb organic and inorganic species
that have charger. The factor parameter for this technology is
the capacity of the electrode adsorption. Biesheuvel and van
der Wal (2010) had performed a research to examine the
performance of a pilot-scale membrane CDI that involved an
ion exchange membrane. The energy efficiency of CDI
membrane with low salinity of feed water is higher compared to RO technology. The clear superiority of membrane
CDI in current efficiency and specific energy consumption
has also been recorded in the previous study by Kim et al.
(2010). Efficiency of salt removal was enhanced by 32.8–
55.9% by using the CDI membrane, and it is depending on
the operating condition. Zhao et al. (2013) showed that the
current efficiency was up to four times reading for membrane
CDI because the “co-ion” effect could be avoided by the
usage of the ion exchange membranes.
ICP can be applied in treating high salinity solutions by
using desalination process. Kim et al. (2016) demonstrated
that brine salinity up to 100,000 mg/L of TDS could be
treated by using ICP desalination and resulting in 70% of
salt rejection. This happens due to the implementation of
multi-stage operation with less membrane fouling/scaling
than ED. Kim et al. (2010) run the ICP studies with high
salinity water (TD *30,000 mg/L) and manage to get
*99% rejection of TDS (at 50% recovery rate) with low
power consumption below 3.5 kWh/m
3 . Kwak et al. (2016)
examined the behaviours of a novel ICP desalination
approach by adopting unipolar ion conduction. For example,
conducting only cations (or anions) with the unipolar ion
exchange membrane stack and the salt removal was recorded
at a given current. As compared to the convention ED, the
power consumption excellently decreased by 50% with the
unipolar cation conduction. Only 3.08 $/m
3 with minimal
power consumption of 5.6 kWh/m
3 are required for optimal
water cost when using ICP at a salt rejection ratio of 50%
(Kim et al. 2017).
3.3 Biological
Biological membrane of bio-membrane is a separating
membrane that works together with a biological activity or
process. The main challenge in the FPW treatment by using
biological processes is the high salinity whereby the
hypersaline pressure is bigger than plasmolysis and osmotic
stress of bacterial cells. However, study by Akyon et al.
(2015) had proved that the engineered microbial mats had
the ability to treat saline FPW with TDS reading of
>100,000 mg/L; 1.45 mg of chemical oxygen demand
(COD). While Freedman et al. (2017) confirmed that biologically active filtration (BAF) could be adapted to treat
SOG wastewater (TDS = 10.5–18.2 g/L, COD = 770–
6360 mg/L), with 80% of COD removal. Besides, the
FPW treatment at the Piceance and DJ Basins demonstrates
that BAF had treated about 67–87% organics in DOC
removal. However, tryptophan-like compounds are difficult
to be removed due to complexation bound to humic/fulvic.
Lester et al. (2014) reported with increasing TDS concentrations of 22,000–45,000 mg/L after 31 h, dissolved COD
removal reduced from 90 to 60%. It shows the need for
further research into the potential and robustness of biological treatments for PW.
Hydrocarbon Separation and Removal Using Membranes
85
in the industrial wastewater treatment consisting high
Na 2 SO 4 . Direct treatment using unfiltered wastewater might
be more suitable for these both technologies compared to
NF-treated wastewater (Quist-Jensen et al. 2017).
3.2 Electrical-Driven
Most of the materials will involve with the electrical charge
when dispersed in polar media. The charge properties of
the ions involved could be a driven factor for the separation process. So, separation rate of the colloids or fine
particles will depend on the surface charge of those particles. Therefore, in membrane technology, the separation
process by the electrically-driven membrane was occurred
due to the alternate ion exchange membranes. There are
two main ED membranes in separation field, cation
exchange membrane (CEM) and anion exchange membrane
(AEM) where the positive charged ions and negative
charged are transported selectively depend on the which
type of the membrane used. The ED processes are potentially feasible for the (partial) desalination of high salinity
waters including PW.
There are several ED-related processes are involved for
treatment of FPW consisting reverse electrodeionization
(REDI) (i.e., the combination of EDI and reverse electrodialysis (RED)) (Lopez et al. 2016), electrodeionization
(EDI), (CDI), ion-concentration polarization desalination
(ICP) (Kwak et al. 2016) and membrane capacitive deionization. A typical EDI unit has same configuration with the
ED, but at least one channel is filled with ion exchange resin.
Contrary to ED, which uses energy to remove salts, RED is a
membrane-based process that producing electricity by mixing two solutions at different concentrations [225]. Lopez
et al. (2016) state that the incorporating ion exchange wafers
in each cell could enhance the REDI performance in order to
shorten the passage ways for the diffusion process and limit
the shadow spacer effect. As compared to a conventional ED
system, a degree of enhanced ion selectivity occurred by
increasing the wafer size and varying the wafer
compositions.
Capacitive deionization (CDI) is a desalination process in
which an electrical energy is used to high surface area
electrodes in order to adsorb organic and inorganic species
that have charger. The factor parameter for this technology is
the capacity of the electrode adsorption. Biesheuvel and van
der Wal (2010) had performed a research to examine the
performance of a pilot-scale membrane CDI that involved an
ion exchange membrane. The energy efficiency of CDI
membrane with low salinity of feed water is higher compared to RO technology. The clear superiority of membrane
CDI in current efficiency and specific energy consumption
has also been recorded in the previous study by Kim et al.
(2010). Efficiency of salt removal was enhanced by 32.8–
55.9% by using the CDI membrane, and it is depending on
the operating condition. Zhao et al. (2013) showed that the
current efficiency was up to four times reading for membrane
CDI because the “co-ion” effect could be avoided by the
usage of the ion exchange membranes.
ICP can be applied in treating high salinity solutions by
using desalination process. Kim et al. (2016) demonstrated
that brine salinity up to 100,000 mg/L of TDS could be
treated by using ICP desalination and resulting in 70% of
salt rejection. This happens due to the implementation of
multi-stage operation with less membrane fouling/scaling
than ED. Kim et al. (2010) run the ICP studies with high
salinity water (TD *30,000 mg/L) and manage to get
*99% rejection of TDS (at 50% recovery rate) with low
power consumption below 3.5 kWh/m
3 . Kwak et al. (2016)
examined the behaviours of a novel ICP desalination
approach by adopting unipolar ion conduction. For example,
conducting only cations (or anions) with the unipolar ion
exchange membrane stack and the salt removal was recorded
at a given current. As compared to the convention ED, the
power consumption excellently decreased by 50% with the
unipolar cation conduction. Only 3.08 $/m
3 with minimal
power consumption of 5.6 kWh/m
3 are required for optimal
water cost when using ICP at a salt rejection ratio of 50%
(Kim et al. 2017).
3.3 Biological
Biological membrane of bio-membrane is a separating
membrane that works together with a biological activity or
process. The main challenge in the FPW treatment by using
biological processes is the high salinity whereby the
hypersaline pressure is bigger than plasmolysis and osmotic
stress of bacterial cells. However, study by Akyon et al.
(2015) had proved that the engineered microbial mats had
the ability to treat saline FPW with TDS reading of
>100,000 mg/L; 1.45 mg of chemical oxygen demand
(COD). While Freedman et al. (2017) confirmed that biologically active filtration (BAF) could be adapted to treat
SOG wastewater (TDS = 10.5–18.2 g/L, COD = 770–
6360 mg/L), with 80% of COD removal. Besides, the
FPW treatment at the Piceance and DJ Basins demonstrates
that BAF had treated about 67–87% organics in DOC
removal. However, tryptophan-like compounds are difficult
to be removed due to complexation bound to humic/fulvic.
Lester et al. (2014) reported with increasing TDS concentrations of 22,000–45,000 mg/L after 31 h, dissolved COD
removal reduced from 90 to 60%. It shows the need for
further research into the potential and robustness of biological treatments for PW.
Hydrocarbon Separation and Removal Using Membranes
85