Surface Modifications of Activated Carbon and Its Impact on Application

Abstract

The main and new surface modification methods of activated carbon (AC) and their influence on application (adsorption capacity) were reviewed. Adsorption capacity is an important issue, contributing to hazardous substances environment management. According to literature, it is true that surface chemistry strongly affects adsorption capacity. Surface chemistry can be modified by several methods that lead to different activated carbon properties. Furthermore, adsorbate properties, and their relationships with surface structure, can impact adsorption properties. Surface modifications can be conducted by adding some atoms to the surface structure, making the surface more acidic or basic. Introduction of oxygen and ammonia atoms (chemical modification) are the main processes to make the surface more acidic and basic, respectively, although may bring chemical wastes to environment. Surface modification is done by chemical and physical modifications that lead activated carbons to present different properties. The main and new methods of chemical and physical modifications are compared and presented in this paper. Some new physical methods, like corona treatment, plasma discharge and microwave radiation, can be applied to cause surface modifications. Corona treatment can be a practical and new way to cause surface modification on an activated carbon surface.

Adsorption and removal of phenoxy acetic herbicides from water by using commercial activated carbons: experimental and computational studies

“…The surface chemistry of the activated carbon is dictated by the heteroatoms (carbon (88%), hydrogen (0.5%), nitrogen (0.5%), sulfur (1%), oxygen (7%)) and inorganics (3%)) present on it [25]. Those heteroatoms represent organic functional groups at the edges of carbon surface.…”

A critical review of point-of-use drinking water treatment in the United States

“…AC can be chemically modified to have an acidic or basic surface. In most cases, an acidic surface has typical functional groups of carboxylic acid, lactone, phenol, or lactol groups, while a basic surface is represented by the existence of chromene, ketone, pyrone, and nitrogen groups 67 . AC can also be impregnated with metals and metal oxides.…”

Optimizing the performance of As(III) and As(V) adsorption process on magnetic carbon xerogel nanocomposites from aqueous solution and natural groundwater wells

“…The surface modi cation of XMC5-600M and XMC10-600M exhibits surface chemistry heterogeneity strongly due to containing of various functional groups and in uence to increase the adsorption capacity, also the main mechanisms controlling the surface chemistry such as repulsive and dispersive interactions, and hydrogen bonds (Pego et al 2019). The results of porous structural morphology with high surface area and low pore volume, were caused by the increment of the ratio of surface area to overall volume of magnetic carbon xerogels that were…”