Resumen de Ecological Risks of Post-artisanal Mining Sites and Their Sustainable Cleaning Techniques

Martin Kofi Mensah, Carsten Drebenstedt, Ibukun Momoriola Ola, Precious Uchenna Okoroafor, Edward Debrah Wiafe

• This study assessed the residual contaminant load of three groups of artisanal gold mining (ASM) impacted lands, thereafter, phytoremediation techniques using Jatropha curcas, Manihot esculenta and organic amendments were used for mitigation. A total of 110 soil samples from 30 ASM sites were investigated for their total contents of Cd, As, Pb, Hg, Zn, Fe and Al. After sample digestion, ICP-MS was used for content determinations. Using activated neem seed extracts (NE) and poultry manure (PM) at different application rates, the phytoremediation potentials of Jatropha curcas and Manihot esculenta were assessed for 270 days after planting. The obtained data were analyzed with SPSS statistics 28 for the ANOVA. The results indicated mining spoils were suppliers of toxic elements in the soil however, their distributions per contaminant varied based on the properties of the ore materials mined. As a result, mine spoils created the processing of oxide and underground rock ores supplied contents of As, Fe, Al, Cd and Zn much more than alluvial mining sites and above tolerable threshold levels. Both J. curcas and M. esculenta exhibited phytostabilizing potentials as larger portions of absorbed elements were stored in their root organs. However, the application of a 25% mixture of neem seed extract and poultry manure or 25% poultry manure only (w/w) to soils reduced the uptake capacity of potentially toxic elements by J. curcas and M. esculenta by 19-38% and 10.4-45% respectively.