The Effect of Addition Humic and Fulvic Acid on the Adsorption of Copper in Gypsum Soils

Abstract

In order to study the interaction between humic acids and gypsum levels and their effect on the adsorption of copper in soil, three soil levels with gypsum content were chosen and prepared in the laboratory. They were treated with three levels of humic acids: (H0) with no addition (0%), (H1) with an addition of (1%), and (H2) with an addition of (2%). Copper ions were measured for the adsorption experiment. The data were treated using Langmuir and Freundlich equations to describe the adsorption nature. The results were as follows: both soils had high values for both Freundlich (82%) and Langmuir (92%) equations. Thus, the second equation outperformed the first equation by a difference of 10%. The adsorption values using the Langmuir equation ranged from (2500-588), while for the Freundlich equation, the sorption capacity values ranged from (186.98-47.53). Only the Langmuir equation recorded values for binding energy, which ranged from (53.76-1.059), and the highest binding energy values were associated with humic acid additions compared to untreated soil.