due to industrialization, population growth and climate change, water is increasingly
polluted which is one of the most serious global challenges and needs to be
urgently solved 1,2. Out of total earth’s water, only around 0.8% is fresh
water. Thus numerous researches have been conducted in an effort to establish
more sustainable technological solutions that would meet increasing water
is the process of removing salts or other minerals and contaminants from
seawater, brackish water, and wastewater effluent and it is an increasingly
common solution to obtain fresh water for human consumption and for
domestic/industrial utilization. Desalination technologies can be classified by
their separation mechanism into thermal and membrane based processes. Thermal
desalination separates salt from water by evaporation and condensation and includes
multistage flash (MSF), multiple effect distillation (MED), and vapor compression
(VC). In membrane desalination, water diffuses through a membrane, while salts
are almost completely retained and includes reverse osmosis (RO) and
electrodialysis (ED) 7–13.
thermal desalination has remained the primary technology of choice in the
Middle East due to easily accessible fossil fuel resources and the poor water
quality of the local feed water, RO membrane processes have rapidly developed
and now surpass thermal processes in new plant installations 3, 14–16. In global
desalination capacity by process, RO has maximum 53% of capacity share 17.
to environmental impact, treatment of industrial effluents and waste water
becomes necessary. Using membrane in water cleaning process has significant
advantage therefor membrane technology become popular in industrial water
treatment. Membrane technology are modular which is easy to scale up, simple in
operation, relatively low energy consumption, no chemical additives, etc.
18–21. Separation with membranes occurs because of the existence of a
gradient across the membrane, and membrane processes may be divided into groups
based on the specific type of gradient. The most common way of categorizing membranes
is to divide them into two groups: non-pressure driven and pressure driven. In
non-pressure driven membrane processes, the driving forces are concentration
gradient (such as gas separation and pervaporation), temperature gradient
(membrane distillation), and electrical potential gradient (electrodialysis).
The pressure driven process having mainly four groups as per the size of
particle they retain: microfiltration (MF), ultrafiltration (UF),
nanofiltration (NF), and reverse osmosis (RO) 22–27.
RO membranes are the major technology for clean water supply, but the main
barrier for universal application of these membranes is fouling. Also, these RO
membranes are vulnerable to chlorine. These two factors can deteriorate membranes
permeability, decrease in salt rejection, rising in energy consumption and
shortening life of membranes. In this paper, surface modification of polyamide
TFC RO membrane to improve fouling resistance and performance of membrane is
reviewed over the years.