Chemically assisted gold phytoextraction in sorghum halepense

Chemically Assisted Gold phytoextraction in Sorghum halepense
Mayra Rodriguez-Lopez a, c *, Victor Wilson-Corral a, b, c, Chris Anderson d, Joel Lopez-Perez a, c

a b

Centro de Estudios JustoSierra (CEJUS), Surutato, Sinaloa, 80600, México. Escuela Preparatoria Guasave Diurna, Universidad Autónoma de Sinaloa (UAS), M. Leyson Perez y Adolfo Lopez Mateos, Colonia Ejidal, Guasave, Sinaloa,81020, México. c Centro de Innovación y Desarrollo Educativo (CIDE) A.C., Surutato, Sinaloa, 80600, México d Institute of Natural Resources, Massey University, Palmerston North, 4414, New ZealandCorresponding author: Phone and Fax: ++(687) 8726081; E-mail: mayraceciliarguez@gmail.com

Abstract In 1998, it was reported for the first time that Brassica juncea plants could be forced to accumulategold using thiocyanate as a soil amendment to increase the solubility of the metal in soil1. This technique is known as induced hyperaccumulation. Since then, various studies have been conductedworldwide to achieve higher levels of accumulation of gold in plant tissues2, 3, 4, 5. The discovery of induced hyperaccumulation is now the basis for the development of a new mining technique known as goldphytomining2. This technique is being actively researched in Mexico. To evaluate its potential for use in gold phytoextraction, plants of the species Sorghum halepense were cultivated in a greenhouseusing a temperature range of 24-33° Mine tailings collected from C. the active El Magistral gold mine, located in the northwest region of Mexico, with a pH of 7.2 and a gold average concentration of2.35 g/ton, was used as a medium for plant growth. Seeds were germinated in a commercial growth mix, and six weeks later, plants were transplanted into pots containing 1 kg of mine tailings. Chemicalfertilizers: nitrogen (N), phosphorus (P) and potassium (K) were applied to the substrate at the time of transplanting. Four weeks later, replicate pots were treated with: thiourea SC(NH2)2 at rates...