Sorption of sulfanilic acid and copper ions by activated carbon modified with metal oxides

The possibility of using activated carbon brand Filtrasorb 300 modified with metal oxides (F300 M) in comparison with unmodified (F300 H) for the simultaneous extraction of organic compounds and copper ions from water has been established. A solution of metal chloride obtained by acidthermal activation of waste from alumina production "red mud" is used as a modifier. The process of sulfanilic acid and copper ions sorption by modified and unmodified activated carbon Filtrasorb 300 (AC F300) is investigated. The structural-sorption characteristics of the studied materials, such as: static exchange cationic and anionic capacities and the number of surface groups (carboxyl, lactone, phenolic), are determined. Positive effect of activated carbon modification by metal oxides that has been obtained as a result of acid-thermal treatment of “red mud” is shown. The presence of negatively charged active centers on modified activated carbon surface makes it possible to increase by 59 % the value of sulfanilic acid adsorption due to the interaction of the material surface with –NH₂ group of the acid with the absence of copper ions in the solution, which is 24 % more than AB F300. Simultaneous presence of copper ions and sulfanilic acid reduces their adsorption on the modified sorbent as a result of blocking the active groups and reducing the electrostatic interaction. Taking into account the complex nature of physical-chemical interactions in a system that contains sulfanilic acid with acidic and basic groups, and the competing effect under certain conditions, it can be expected that the modification of activated carbon with a metal chloride solution (obtained by acidic activation of alumina production wastes with their subsequent conversion to oxide form), is a promising direction in water treatment in case of containing both organic compounds and non-ferrous metal ions

sorption; modified activated carbon; structural-sorption characteristics; sulfanilic acid; copper ions; water treatment