Oxyanions are ubiquitous in soils, organisms and the environment. Due to their unique chemical structure, oxyanions can be easily transferred into other systems. Carbonate (CO 3 2− ), nitrate (NO 3 − ), phosphate (PO 4 3− ), silicate (SiO 4 2− ) and sulfate (SO 4 2− ) are the major oxyanions in organisms and the soil environment, whereas arsenate (AsO 4 3− ), antimonate (SbO 4 3− ), borate (BO 3 3− ), selenate (SeO 4 2− ), and...