Removal of emerging contaminants in water treatment by an application of nanofiltration and reverse osmosis

Abstract Any unwanted harmful material is known as contaminant. Contaminant can be natural or manmade origin. Pollutants which were not previously or not regularly present in environment are known as emerging contaminations. They are categorized according to their properties, utility or sources. Emerging contaminations include personal health care products, industrial chemicals, heavy metals, biocides, surfactants, gasoline additives, flame retardants etc., which are harmful at above their tolerance level to living systems. By various activities or discharge of effluent, these emerging pollutants enter to the water body. So, their elimination is compulsive as they are toxic if present inside of human, animal or other living creatures. Various filtration methods are used for their removal like, microfiltration, ultrafiltration, nanofiltration and reverse osmosis. This chapter mainly comprises study of nanofiltration and reverse osmosis for removal of various toxics. As microfiltration and ultrafiltration has limitations for removal of impurities nowadays, reverse osmosis, and nanofiltration techniques are used to overcome these barriers. Nanofiltration and reverse osmosis are mainly influenced by pressure, temperature, viscosity, transmembrane pressure, osmotic pressure, flux rate, concentration polarization, pore size of the membrane, and fouling. Both of these methods have some advantages and limitations over others. However, due to more advantages, one can use these methods for treatment of landfill leachate or emerging contaminations containing waste water to make it potable.