Given the chemical treatment applied to sugarcane bagasse in adsorption of heavy metals how can I exclude the effect or factors that the chemical modification affects?
You can study comparative adsorption between the chemically treated and pristine sugarcane bagasse for the heavy metals adsorption. Only then you can access the effects of the modificane based on the adsorption efficiency between the two adsorbents.
Though most chemical treatments will improve adsorption, i think it's better if you compare the performance of the native and chemically treated sorbent