PURIFICATION TECHNOLOGY AND SELECTION CRITERIA FOR WASTE WATER TREATMENT; A REVIEW.

This paper presents different methods for water purification and selecting the best techniques of wastewater treatment. Contamination word indicates pollution. It makes water completely unfit for the use of drinking. The accepted goals of the treatment are to remove unwanted constituents in the water and to make it safe to drinking or fit for domestic usage, but water purification may also be designed for a variety of other purposes, including fulfilling the requirements of medical, pharmacological, chemical and industrial applications. In this paper, a practical approaches are presented for selecting the wastewater treatment process based on the organic and inorganic pollutants present on surface water. The aim of this review of wastewater treatment is the protection of the environment in a manner commensurate with public health and socio-economic concerns. Understanding the nature of wastewater is fundamental to design an appropriate treatment technology in order to ensure the safety, efficacy and the quality of the treated wastewater. Further, improved public education to ensure awareness of the technology and its benefits, both environmental and economic, is recommended. The utility of any water recycling technique at a commercial level depends on the cost of construction, maintenance and operation. Taking all these points into consideration, ion exchange and adsorption is the best and most universal technique as it is used for the removal of a wide variety of organic and inorganic pollutants. It is also a rapid process with a low cost. In this review, we present a summary of advance technologies for water purification and its application. The source of pollutants and impurities present in water are first introduced, and then the primary secondary and tertiary treatment process for removing various water pollutants, such as salt, metallic ions, anions, nanoparticles, organic chemicals, and biological substrates, are discussed. In addition, this work will be valuable for readers to understand the design and fabrication of various nonporous membranes, and their potential purification mechanisms towards different water pollutants.