Recent Trends in Membrane Processes
for Water Purification of Brackish Water
Muhammad Sarfraz
Abstract
Naturally occurring brackish water, normally containing
500–10,000 mg/L of total dissolved solids, is not safe for
direct consumption due to its salinity. The salinity level
needs to be reduced to a level below 500 mg/L to make it
drinkable as per recommendations of the World Health
Organization (WHO). Reverse osmosis (RO) process for
water desalination purposes is currently considered to be
the most effective, economical, efficient, and optimized
method dominating the water purification market. An
extensive research has been carried out in the field of
membrane-based brackish water reverse osmosis
(BWRO) process to improve its desalting performance.
Various aspects of a BWRO process system such as
nature and type of membrane material, module design
parameters, process configuration, energy recovery
devices, operating parameters, economical aspects are
reviewed in this chapter. Theoretical background of a
BWRO process, transport mechanism through BWRO
membranes, and desalination performance of BWRO
membranes are considered here. An updated review of
different commercially available BWRO membranes,
membrane modules, and process configurations is also
provided. In addition, major components of a typical
BWRO plant such as pretreatment unit, pumping system,
membrane module section, and post-treatment unit are
also described in this review. General process considerations, economic aspects, energy recovery options, and
process optimization of a BWRO system are discussed
here. High-performance BWRO membranes prepared
from polymeric and thin-film composite materials are
inserted in commercial spiral wound modules to make the
desalting process economically efficient. Concentrated
brine rejected from a BWRO plant can be economically
treated by installing solar stills at sunlit places. A double-stage membrane process can enhance water recovery
of BWRO plants from the usual range of 85–90% to
about 95–98%. Brackish water can be purified by BWRO
process at reduced cost by using high rejection membranes, installing larger pressure vessels, and adopting
hybrid membrane design.
Keywords
Brackish water Á Desalination Á Reverse osmosis Á
Reverse osmosis membranes Á Integrally skinned
anisotropic membranes Á Membrane modules Á BWRO
plant Á Water flux Á Salt rejection Á Water pretreatment
Nomenclature
Abbreviations
BWRO Brackish water reverse osmosis
CA
Cellulose acetate
ED
Electrodialysis
MD
Membrane distillation
MEE
Multi-effect evaporation
MSFD Multistage flash distillation
MVCD Mechanical vapor compression distillation
NF
Nanofiltration
PA
Polyamide
PVC
Polyvinyl chloride
RO
Reverse osmosis
SWRO Seawater reverse osmosis
TVCD Thermal vapor compression distillation
WHO
World Health Organization
Symbols
A
Membrane permeability coefficient for water
B
Membrane permeability coefficient for salt
C
Solute concentration (mol/L or mg/L)
M. Sarfraz (&)
Department of Polymer and Process Engineering, University of
Engineering and Technology, Lahore, 54890, Pakistan
e-mail: msarfraz@uet.edu.pk
© Springer Nature Switzerland AG 2021
Z. Zhang et al. (eds.), Membrane Technology Enhancement for Environmental Protection
and Sustainable Industrial Growth, Advances in Science, Technology & Innovation,
https://doi.org/10.1007/978-3-030-41295-1_4
39
for Water Purification of Brackish Water
Muhammad Sarfraz
Abstract
Naturally occurring brackish water, normally containing
500–10,000 mg/L of total dissolved solids, is not safe for
direct consumption due to its salinity. The salinity level
needs to be reduced to a level below 500 mg/L to make it
drinkable as per recommendations of the World Health
Organization (WHO). Reverse osmosis (RO) process for
water desalination purposes is currently considered to be
the most effective, economical, efficient, and optimized
method dominating the water purification market. An
extensive research has been carried out in the field of
membrane-based brackish water reverse osmosis
(BWRO) process to improve its desalting performance.
Various aspects of a BWRO process system such as
nature and type of membrane material, module design
parameters, process configuration, energy recovery
devices, operating parameters, economical aspects are
reviewed in this chapter. Theoretical background of a
BWRO process, transport mechanism through BWRO
membranes, and desalination performance of BWRO
membranes are considered here. An updated review of
different commercially available BWRO membranes,
membrane modules, and process configurations is also
provided. In addition, major components of a typical
BWRO plant such as pretreatment unit, pumping system,
membrane module section, and post-treatment unit are
also described in this review. General process considerations, economic aspects, energy recovery options, and
process optimization of a BWRO system are discussed
here. High-performance BWRO membranes prepared
from polymeric and thin-film composite materials are
inserted in commercial spiral wound modules to make the
desalting process economically efficient. Concentrated
brine rejected from a BWRO plant can be economically
treated by installing solar stills at sunlit places. A double-stage membrane process can enhance water recovery
of BWRO plants from the usual range of 85–90% to
about 95–98%. Brackish water can be purified by BWRO
process at reduced cost by using high rejection membranes, installing larger pressure vessels, and adopting
hybrid membrane design.
Keywords
Brackish water Á Desalination Á Reverse osmosis Á
Reverse osmosis membranes Á Integrally skinned
anisotropic membranes Á Membrane modules Á BWRO
plant Á Water flux Á Salt rejection Á Water pretreatment
Nomenclature
Abbreviations
BWRO Brackish water reverse osmosis
CA
Cellulose acetate
ED
Electrodialysis
MD
Membrane distillation
MEE
Multi-effect evaporation
MSFD Multistage flash distillation
MVCD Mechanical vapor compression distillation
NF
Nanofiltration
PA
Polyamide
PVC
Polyvinyl chloride
RO
Reverse osmosis
SWRO Seawater reverse osmosis
TVCD Thermal vapor compression distillation
WHO
World Health Organization
Symbols
A
Membrane permeability coefficient for water
B
Membrane permeability coefficient for salt
C
Solute concentration (mol/L or mg/L)
M. Sarfraz (&)
Department of Polymer and Process Engineering, University of
Engineering and Technology, Lahore, 54890, Pakistan
e-mail: msarfraz@uet.edu.pk
© Springer Nature Switzerland AG 2021
Z. Zhang et al. (eds.), Membrane Technology Enhancement for Environmental Protection
and Sustainable Industrial Growth, Advances in Science, Technology & Innovation,
https://doi.org/10.1007/978-3-030-41295-1_4
39