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A desalination plant, which is based on reverse osmosis technology, is aimed to decrease the shortages in potable water. Desalination technologies can be classified into two major types due to their separation mechanisms. The first is based on thermal distillation, while the second is based on membrane separation via reverse osmosis (RO).The main issue of using RO membranes is the sensitivity of these membranes to fouling by different suspended solids, such as algae, microbes, and other foulants. Therefore, pre-treatment is needed to remove the undesirable components from the seawater. UF membranes are considered an effective pre-treatment solution for RO-desalination processes by using them in the removal of microbiological contaminants. The main focus of this research however, is on ultrafiltration membranes via surface modification on those membranes. Biofouling, which is an irreversible deposition and accumulation of bioorganic materials onto the surface of the UF membranes, is one of the major challenges for the technology of membranes used in desalination processes. As a result, anti-biofouling coatings are needed to be applied to reduce biofouling on hydrophobic polymers such as polysulfone UF membranes. The first stage involved in the fabrication of these membranes has been done by applying different types of coatings include; a thin layer coating of polydopamine and polydopamine-initiator primer onto the membrane surface. The second stage is known as secondary treatment process, which was to grow biopassive and/or bioactive coatings on the membrane surfaces using Atom transfer radical polymerization technique ARGET-ATRP. These types of coatings should be hydrophilic, are charge neutral, have high surface energy, have a stable surface hydration, and have the ability to form coatings with a low surface roughness to reduce bacterial affinity on such membranes. In order to produce effective coatings that reduce fouling on different Ps UF membranes, many polymers have been used to apply biopassive low fouling coatings. Some of these coatings have been reported as biopassive coatings including polymers with zwitterionic structure such as; phosphabetaine, phospholipids, and sulfobetaine (SBMA). Other types of coatings are known as bioactive coatings based on antimicrobial agents such as (2-methacryloyloxyethyl) trimethyl ammonium chloride (MTAC). All types of coatings were characterised by ATR-FTIR (Attenuated Total Reflectance-Fourier transform infrared spectroscopy), Thermo gravimetric analysis (TGA), and Scanning electron microscopy (SEM). Also, the measurements of the water flux rate (pure water permeability) have been done using the stirred cell experiments. It has been found in this research that biopassive surface coatings reduce the proteins adsorption and thus the adhesion of bacteria, typically through the incorporation of hydrophilic well-hydrated polymers that are either covalently immobilized or physisorbed on the surface. Zwitterionic materials display high resistance to the adhesion of bacteria and biofilm formation in long-term cell adhesion tests. Similarly, the bioactive polymers discussed within this research can kill the bacteria on contact through the immobilization of antibiotics and antimicrobial agents due to the ability of antimicrobial polymers to be attached to the surfaces without losing their biological activity.
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