Similarity Siam weed (Chromolaena odorata L.) for phytoremediation of artisanal gold mine tailings

The potential of Chromolaena odorata to remove Hg and Pb from tailings from cyanidation processing of artisanal gold mining at Lombok, Indonesia was investigated in a glasshouse experiment. The tailings were amended with farmyard manure (FYM) and biochar added with 5 and 10 g kg–1 FeSO4 before growing C. odorata plants. Chromolaena odorata grew well on amended tailings, but it did not grow on untreated tailings. Application of organic amendments and FeSO4 decreased tailing pH from 9.2 up to 6.6 (e.g., FYM+10 g FeSO4 kg–1 soil) and increased its organic C and N, P, K levels. Total absorption of Hg in C. odorata plants ranged from 5.8 to 8.7 mg kg–1 and Pb from 55 to 61 mg kg–1 in the amended substrates