Abstract:
Pressure-driven processes have come a long way since they were introduced. These
processes, namely Ultra-Filtration (UF), Nano-Filtration (NF), and Reverse-Osmosis (RO), aim to
enhance the efficiency of wastewater treatment, thereby aiming at a cleaner production. Membranes
may be polymeric, ceramic, metallic, or organo-mineral, and the filtration techniques differ in
pore size from dense to porous membrane. The applied pressure varies according to the method
used. These are being utilized in many exciting applications in, for example, the food industry,
the pharmaceutical industry, and wastewater treatment. This paper attempts to comprehensively
review the principle behind the different pressure-driven membrane technologies and their use in
the removal of heavy metals from wastewater. The transport mechanism has been elaborated, which
helps in the predictive modeling of the membrane system. Fouling of the membrane is perhaps the
only barrier to the emergence of membrane technology and its full acceptance. However, with the
use of innovative techniques of fabrication, this can be overcome. This review is concluded with
perspective recommendations that can be incorporated by researchers worldwide as a new problem
statement for their work.
