Comparison of sorbents for extraction of nickel (II) cations from aqueous media

An urgent ecological and technological problem is the purification of natural and waste water from nickel cations and control of their content, since nickel cations belong to the third class and are hazardous to human health. To date, a large number of methods for removing nickel (II) cations from water have been created, the main of which can be considered sorption. In turn, the literature contains a variety of information about the most effective sorbents for cleaning from nickel cations, which sometimes contradict each other. The work determined the equilibrium characteristics of the sorption of nickel (II) cations on various polar sorbents on cation exchangers porous carboxyl Tokem 200, chelated iminodicarboxylic Amberlite IRC 748, gel sulfonic cation exchanger KU-2, experimental phosphoric acid gel KFP; strongly basic gel anion exchanger AV-17, as well as natural adsorbents flint and shungite. Sorption isotherms were obtained and described by the Langmuir equation, and the most promising materials for removing nickel cations from aqueous media were established. It has been determined that the studied sorbents, according to their equilibrium sorption characteristics, can be arranged in the following order: Tokem 200> KFP> Amberlite IRC 748> AV-17> KU-2> Flint> Shungite. The most effective sorbents for removing nickel (II) cations from aqueous solutions can be considered a prototype of a phosphate cation exchanger for gel CFP and a carboxyl porous cation exchanger Tokem 200. separating nickel cations from an aqueous solution.