SORPTION OF ORGANIC DYE METHYLENE BLUE TO HUMIC SUBSTANCES

Humic substances represent a wide range of organic compounds generated by gradual decomposition of plant residues and dead organisms in our ecosystems. They are among the most widespread compounds in the world that contain a huge amount of carbon in its structure. Is contains a lot of functional groups and mainly carboxyl -COOH group. We decided to use humic acid methylation to investigate the effect of the carboxyl group on our experiments. Humic substances are able to bind various pollutants from Industrial production, agriculture and other human activities (like heavy metals, pesticides, herbicides, dyes, etc.). The interaction possibilities can be different: ion exchange, hydrogen bridge formation, coulombic interactions, hydrogen bridges, van der Waals interactions, hydrophobic interactions, absorption, etc. The purpose of this work is to measure the decrease of selected initial concentrations of the selected organic dye probe (methylene blue) with a sample of lignitic humic acid and a methylated sample of that humic acid. The obtained humic acid sample will undergo a desorption experiment under the same time conditions. The output of the work will also monitor the ratio between the amount of adsorbed and desorbed methylene blue. The results can provide more details about the stability dye-humic complexes and the mobility of dye in systems containing humic substances.