Activated carbon fibers water treatment using

Activated carbon is the most important carbon material used to adsorb organic solutes from aqueous solutions, although the use of activated carbon fibers and activated carbon cloths has been continuously growing in recent years. These carbon materials are applied across a wide spectrum of systems such as drinking water and wastewater treatments and are used in the food, beverage, pharmaceutical, and chemical industries. Furthermore, activated carbon adsorption has been cited by the US Environmental Protection Agency as one of the best available environmental control technologies [1]. 

Thermal Insulation is by far the most Important present application of oxide fibers. Transition alumina fibers, e.g., eta-alumina fibers, are produced at Intermediate firing temperatures and are used as supports for catalysts and Insulation tiles such as those used for the space shuttle orbiter [1-2]. Carbon fiber felts are used as internal thermal insulation for vacuum furnaces at extremely high temperatures. Activated carbon fibers, which are obtained by partial oxidation of selected carbon fibers, have extremely small pores and very high specific surface areas, ranging from 500 to 3000 mVg. They are of great interest in ultrafiltration as membranes for the treatment of used waters and liquids [3-5]. 

Dichlorodiphenyltrichloroethane (DDT), DDT is a potential endocrine disrupter even at ng-L-1 levels. It is forbidden as a kind of pesticides from 1980s. While DDT is found in a higher concentration from the lake, river and the atmosphere, water, sediment, soil. It has been detected in many aquatic systems, from the Arctic Antarctic marine mammals to the birds, in the people s milk for human consumption, fish and so on. This raises serious problems in aquatic organisms and animals. Due to their harmful effects on the environment and biological body and the difficulty to degradation by the common treatment methods, it s important to use a suitable adsorbent to remove it activated carbon fiber and nanofiber are good adsorbent to eliminate it [173]. 

Using pitch-based ACFs, Mochida et al. [132] reported 87% conversion at room temperatnre in dry air. Lower conversions were obtained in the presence of water vapor. The anthors found that heat treatment at 1123 K enhanced the activity of the fibers. Such treatment removes oxygen functional groups from the surface of the ACFs the vacant sites created as a result of this treatment were thought to be the active sites for the reaction. On the other hand, the hydrophobic surface obtained after the heat treatment helps to decrease the amount of water adsorbed, which decreases NO conversion in humid air. An interesting point noted by Mochida et al. [131] is that PAN- and pitch-based ACFs exhibited the reverse order of activity for the oxidation of SO2 and NO. Thus, pitch fibers were best for NO oxidation, while PAN fibers were found to be more active for SO2 oxidation. No explanation was provided by the authors for this finding, which certainly reflects the different surface chemical properties of the two fiber types. A detailed kinetic study of this process was presented in a subsequent paper [133], while Guo et al. [134] compared the performances of different carbon fibers (PAN, pitch) and activated carbons. 

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