Assessment and management of arsenic contamination in groundwater from Sanso, Ghana: Health risk implications, source identification, adsorption and immobilization for safe disposal

Arsenic contamination in groundwater poses global health risks, but safe removal and disposal remain a significant concern for groundwater owners in developing countries. This study aimed to evaluate the health risks, sources, and concentration of arsenic species in groundwater from Sanso, Ghana, and further synthesize and characterize magnetic activated carbon (Fe-CAC) for arsenic removal, and solidify and stabilize the arsenic loaded onto Fe-CAC using cement, nickel oxide, and eggshell waste (AFCNE). Groundwater samples were collected from the Sanso community in Ghana. Arsenic speciation was determined using standard analytical methods and a flame atomic absorption spectrophotometer. Scanning electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy analysis were used to characterize the materials. The findings revealed that mean concentrations of total arsenic (15.463 μg/L) and arsenite (13.645 μg/L) did not conform to the WHO guideline value of 10 μg/L. The multivariate analysis revealed impacts of illegal mining activities, geological influences, and geochemical conditions strongly influencing arsenic enrichment and transport in aquifers. Children showed a higher chronic daily exposure to arsenic than adults, with oral exposure being significantly higher than dermal exposure. The cumulative carcinogenic and non-carcinogenic risk exceeded 10^-4 and 1, respectively, indicating a high potential for skin cancer, bronchitis, and skin lesions. The Fe-CAC adsorption minimized arsenic concentrations from 15.463 to 0.0302 μg/L, accomplishing a removal efficiency of 99.769 %, proving its effectiveness in treating arsenic in groundwater. The leaching test showed a significant reduction in arsenic release, ranging from 1.32 to 0.20 μg/L below the USEPA limit of 5 μg/L, indicating AFCNE long-term stability in immobilizing arsenic and its suitability for safe landfill disposal. This study suggests the need for integrated remediation strategies for long-term arsenic mitigation, continuous monitoring, community awareness, and swift implementation of effective water policy interventions for sustainable groundwater quality.