Determining the possibility of using selected composts to remove aqueous solutions from zinc ions in concentrations of up to 1000 mg.L^-1

Czestochowa University of Technology (CUT), Faculty of Infrastructure and Environment, Institute of Environmental Engineering, 42-215, Czestochowa, Brzeznicka 60 a, Poland

^* Corresponding author: ikupich@is.pcz.pl

Abstract

The high sorption capacity of compost indicates that it can be a cheap alternative to the currently used sorbents, also in the case of heavy metals. The sorption of zinc from aqueous solutions with the use of the selected compost types not meeting standards was carried out in accordance with the batch method in the constant contact conditions of a liquid (100 mL) and a solid (5,0 g) when the concentrations of Zn²⁺ were 100, 250, 500, 750 and 1000 mg·L^-1. The efficiency of the process decreased with an increasing Zn²⁺ concentration and was strongly dependent on the quality of the compost and the composition of the initial compost mixture. For the highest concentration of zinc, the best efficiency (nearly 70%) was obtained in case of the commercial compost, while the lowest one (only 25%) in the case of the compost made only from green waste and prepared in a garden compost bin. The experimental results were described using the Freundlich isotherms and the obtained equation parameters show the adsorption process. It was found that compost can serve as an efficient sorbent with regard to zinc ions.