Volume: 5, 2026
5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: E017
DOI: https://doi.org/10.24326/ICDSUPL5.E017
Published online: 22 April 2026
Biochar modification with iron species to improve roxarsone and As(V) adsorption ability
Kinga Morlo*, Ryszard Dobrowolski and Joanna Dobrzyńska
Department of Analytical Chemistry, Maria Curie-Sklodowska University, 3 M. C. Sklodowska Sq., 20-031 Lublin, Poland
* Corresponding author: kinga.morlo@mail.umcs.pl
This study focuses on the development of effective methods for removing arsenic species, particularly using iron-modified biochars. Roxarsone, an organoarsenic compound formerly used as a coccidiostat in poultry feed, has been banned in the European Union since 1999 and in the United States since 2013. Despite these restrictions, its use persists in developing countries such as India and Pakistan. Roxarsone is minimally metabolized and excreted unchanged from animal body, often accumulating in organic fertilizers at concentrations up to 40 mg·kg−1, which can leach into soils and groundwater, where it can transform into more toxic inorganic arsenic species, e.g. As(V). Long-term exposure to arsenic-contaminated water poses serious health risks, including carcinogenic effects. The World Health Organization recommends a maximum arsenic level of 10 μg·L−1 in drinking water, highlighting the need for cost-effective arsenic removal technologies. Adsorption, especially using biochar due to its high efficiency and low cost, is a widely applied method. Iron modified biochars, with their excellent affinity for arsenic species, facilitate the selective adsorption and stabilization of arsenic complexes on their surfaces.
This research involves the synthesis of biochars, their modification with different iron compounds and modification procedures, and the physicochemical characterization of the prepered materials. Additionally, preliminary results of model optimization experiments are presented, focusing on the adsorption data of roxarsone and As(V) onto the studied biochar-iron composites. The research includes the influence of pH on adsorption efficiency, explores adsorption kinetics, and estimation the adsorption capacities of the materials with respect to the target arsenic species. Based on the obtained research data, it can be clearly stated that the method of biochar modification with iron compounds significantly influences on its structural and surface properties. These changes have a direct impact on arsenic contaminants adsorption efficiency. Unmodified biochar shows the lowest adsorption capacity towards As(V) regardless of the pH values in the studied range, highlighting the necessity of chemical modification with iron species. Importantly, the research sheds light that in order to effectively remove both organoarsenic forms, such as roxarsone, and inorganic forms like As(V), a hybrid architecture of the adsorbent is crucial, containing both the biochar as matrix and deposited iron species.
Keywords: adsorption; arsenic species; biochar modification; iron forms
How to cite
Morlo K., Dobrowolski R., Dobrzyńska J., 2026. Biochar modification with iron species to improve roxarsone and As(V) adsorption ability. In: 5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL5.E017