Materials, Methods & Technologies, Volume 17, 2023

Abstract: In order to satisfy man's existential needs for food and energy, two major problems arise in the environment. Excessive use of herbicides based on acetochlor (ACT) in order to maximize food production causes surface water contamination. Its effect on endocrine disorders in humans and animals has been proven. By burning coal in thermal power plants, in addition to electricity, we also get huge amounts of by-products in the form of fly ash and boiler ash, the disposal of which requires large areas of land, a huge amount of water and energy. These problems represent a major health, environmental and economic problem. In this work, the feasibility of using adsorbent based on fly ash as a cheap adsorbent for the removal of herbicide acetochlor from water was investigated instead of using commercial activated carbon. This study recognizes that fly ash (FA) is a promising adsorbent for the removal of various pollutants. Fly ash from the Morava thermal power plant was simply chemically treated with CaO and water to give modified fly ash (MFA), which proved to be an effective adsorbent for the removal of acetochlor (ACT) from water. The content of lime (CaO and water) in the fly ash was optimized in relation to the adsorption capacity of acetochlor using the D-Optimal Design method of response surfaces (RSM). For this purpose, the commercial software "Design expert 9" was used. The results showed that the pseudo-second-order rate equation effectively describes the adsorption kinetics and that the adsorption equilibrium is established after 60 minutes. The Freundlich model showed a better fit to the adsorption isotherm than the Langmuir model. The maximum Langmuir capacity of the adsorbent for ACT was 102.6mg g-1 at 25 °C at a solution pH of 8.