. Comparison of sorption properties of zoocompost in relation to Cd2+, Zn2+, Cu2+ ions

Abstract

The study of relationships between zoocompost containing humic acids and metal ions is of great importance not only for predicting the redistribution of humic compounds and heavy metals in the environment, but also for developing methods for controlling the processes of migration of pollutants in natural environments, creating new materials for protecting the environment and remediating soils contaminated with heavy metal ions. The article compares the sorption capacity of zoocompost cultivated by the Black Lionfly fly, containing humic acids and to Zn2+, Cd2+, Cu2+ ions. It was established that with an increase in the dose of zoocompost, the concentration of heavy metal ions in the solution decreases and the cleaning efficiency reaches 94.6% for Cd2+, 75.2% for Zn2+ and 70.4% for Cu2+. A comparison of the stability constants of complex ions of cadmium, zinc and copper showed that more stable metal-humic acid complexes are formed by Cd2+ and Zn2+, while Cu2+ is characterized by a lower degree of connectivity. The obtained sorption isotherms and values of the sorption capacity of zoocompost for Cd2+ (0.490 mmol/g), Zn2+ (0.225 mmol/g) and Cu2+ (0.145 mmol/g) indicate the specific interaction between the heavy metal ions and functional groups of humic acids included in the composition of zoocompost, and also confirm the theoretical series of stability of chelates Cd < Zn < Cu.