Benfdila Arezki

Abstract

The present lecture deals with water purification and treatment advances in the nanotechnology era. Many techniques and procedures have been developed and used to treat and purify water, however some of them are expensive or difficult to implement. The prominent problem for population health is the drinking water accessibility as more than 70% of water goes to agriculture and food supply. The cleaning and treatment process obeys the scheme given in Fig.1. Nanotechnology based techniques have been widely introduced and gave better efficiency and accessibility as well as implantation. Nanomaterials come to be an important issue for water purification and treatment. These nanomaterials have typical properties such as removal of organics, heavy metals, bacteria, (arsenic) and radionuclides, media filters and powders. Adsorption by carbon nanotubes are highly used for water purification and nanomembrane processes are for water treatment (desalination, and wastewater). Photocatalysis is used to remove oxidants and kill pathogens using nanomaterials reaction. Disinfection uses nanoplants that removes bacteria and some viruses without any additional chemical solutions. This is achieved by killing the microorganisms present in water using nanoparticles (silver) which are easily produced and tile lasting, which is suitable for developing countries. Graphene material is found to be an efficient nanofilter and particle absorbent and repellent; it is used in nanomembrane filtration as well as surface adsorption. Nanomaterials can be three classes as shown in Fig.2. Organic, inorganic and polymer nanomaterials. Each type of nanomaterial is used for a specific agent/particle remover. Carbon based nanomaterials are found to be of paramount interest in drinking water production. These materials are not toxic and easy to produce. Figure 2 shows the principle nanomaterials that are the CNTs, the carbon dot and the graphene. CNTs are have three forms and can be used as filters, agent/contaminant trappers or killers. Graphene is mostly used for nanofiltering. In this talk, an overview on nanotechnology developments and applications in the various fields will be discussed. A special consideration is given to nanomaterials, structures, properties, and application in order to emphasize their application in water cleaning and treatment. Water treatment and purification technology is discussed according to Fig. 1. Nanomaterial engineering and technology is introduced in this process while the benefits and drawbacks are highlighted. Case study of accessibility to the nanotechnology water processing in developing countries is discussed.