Influence of nanoporous carbon materials surface morphology and functional groups on pesticide adsorption from water solution

Due to the fact that surface characteristics of carbon material depend of carbon precursor nature and manufacturing parameters, the main objective of this work was to find appropriate carbonization and activation parameters in order to obtain activated hemp fibers (ACh) and carbon monolith (CM) with good adsorption properties toward pesticides. Chemical modification of short hemp fibers prior to carbonization was used to examine the influence of carbon precursor chemical structure and morphology on carbonized material characteristics. The factor of the influence on the final porous texture and adsorptive properties of activated carbon materials by production conditions are as follows: carbonization temperature, activating agent/carbon material ratio and activation temperature. Optimal production conditions were selected based on the adsorption properties of carbonized materials toward pesticides. Activated hemp fibers and carbon monolith surface were characterized by specific surface area and porosity, obtained from adsorption and desorption isotherms of N2 and by the amount and nature of surface oxygen groups, obtained by temperature-programmed desorption (TPD). As a specific test for surface activity, adsorption of silver was used. Obtained carbon materials impregnated with silver were also used for water disinfection. The possibility of using obtained materials in water purification was tested through adsorption of heavy metals and pesticides. Adsorption of heavy metal ions was tested through adsorption isotherms and kinetics. The experimental data obtain in this way was used for development of the mathematical model that would describe both the phenomenon of metal ions transport through the porous matrices, and the structure of carbonized hemp fibers. For the pesticides adsorption study, pesticides with different chemical structure were chosen: acetamiprid, dimethoate, nicosulfuron, carbofuran and atrazine. Decrease of pesticide concentration, as a consequence of the adsorption, was determined by liquid chromatography–tandem mass spectrometry technique. The possibility of using carbonized and activated hemp fibers as a sorbent in the solid-phase extraction (SPE) for pesticide analysis in water samples were also tested. Abstract The removal of lignin by chemical modification of carbon precursor brings the increase in the amount of surface oxygen groups, while polymorphic transformation of Cell I to Cell II increases specific surface area. Scanning elect