Seasonal and Temporal Distribution of Arsenic

In this study seasonal and temporal distribution of arsenic was assessed over a period of one year.During the study water and soil samples were taken from streams, rivers, old and active process ponds, tailings dams, tailings footprints, heap leach sites, arsenic trioxide storage sites, waste rock dumps as well as gold processing plants which treat arsenic ores. The study concluded the temporal distribution of arsenic in surface water follows a linear seasonal trend whereas all year round it generally follows a polynomial trend. It is not advisable to attempt to predict the concentration of arsenic in groundwater on the basis of the Fe contents alone. However, the presence of high Fe is a possible indication of high arsenic in groundwater. It is noted however that wells with low Fe will tend to have low arsenate concentration. There is a temporal nonlinear relationship between As and Fe concentrations which proposes a natural remediation of the polluted water source and indicates how long it may take for the water to revert to a compliant concentration when measures are taken to stop activities that mobilize arsenic. This suggests that if the current anthropogenic activities releasing arsenic is halted and with the appropriate concentration of iron in solution, the surface water may demobilize arsenic back into the host mineralogy. There are seasonal changes in arsenic content of the monitoring boreholes in Arsenic-trioxide Storage Area (ASA) suggesting the mobility of arsenic with inï¬ ltrating water as an important transport pathway to groundwater.