ABSTRACT
Various pollutants like heavy metals, oils, and other industrial discharges are known to contaminate water. Currently, membrane technology is considered as more efficient than other conventional methods for water treatment. Several treatment technologies for wastewater have been adopted for the management of aquatic systems. Pressure-driven membrane processes remove around 99% of contaminants. Different combinations of pressure-driven processes are in use for the treatment of wastewater. A pressure-driven method uses hydraulic pressure for the removal of heavy metals from wastewater. Polymer-enhanced ultrafiltration is another method that helps to remove sulfate ions from industrial wastewater. Forward osmosis (FO) is known to be helpful in recovering water from oily wastewater. Concentration polymerization is common to all membrane filtration processes. For purification of drinking water, various hybrid membrane processes have been used. Nanofiltration (NF), ultrafiltration, and microfiltration (MF) are some of the other methods used for the treatment of wastewater. The deposition of solid particulates, microbes, organic materials onto the membrane surface or within the membrane pores may cause fouling of the membrane. The fouling of the membrane can be controlled by using various cleaning methods. Biochemical cleaning is the most sustainable method among all the other methods. On the contrary, physical and chemical methods are not suitable as they use harsh conditions and chemicals for cleaning purposes. Pretreatment of wastewater helps in utilization of energy as it also reduces the chances of membrane fouling. Shortage of clean water at the global level requires that more research be undertaken for the treatment of wastewater.
