Organoarsenic feed additives are widely used in many developing countries to promote growth and suppress bacterial and parasitic diseases of livestock. However, these compounds are barely metabolized in the animal bodies and can degrade to the more toxic inorganic forms of arsenic, namely, arsenite and arsenate, after being introduced into the environment.
New insights on the abiotic transformation of organoarsenic feed additives in soil environment have been gained through the research in the research group led by Prof. Hefa Cheng at Guangzhou Institute of Geochemistry, CAS. Dr. Lingling Wang systematically investigated the degradation of p-arsanilic acid (p-ASA) mediated by a common manganese oxide, birnessite (δ-MnO2). The adsorption and degradation of p-ASA, arsenite generation and oxidation, arsenate adsorption and release under different pH conditions, as well as the formation of inorganic and organic degradation products and the degradation pathways were studied. This work was published recently in the journal of Environmental Science & Technology (49:3473-3481, 2015). The results could help better understand and predict the fate of p-ASA in surface soils rich in birnessite (e.g., the acidic red soil in southern China).
This work was supported in parts by the Natural Science Foundation of China (Grant Nos. 41322024 and 41472324), the Postdoctoral Science Foundation of China (2013M540670), and the National Program for Support of Top-notch Young Professionals.
Article Links: http://pubs.acs.org/doi/abs/10.1021/es505358c
(Supplied by the State Key Laboratory of Organic Geochemistry & Science and Technology Department, CASGIG)