Assessment of Mercury Levels in Water Bodies of Kambele-Batouri, East Region of Cameroon and Treatment with Activated Carbon

Abstract

Mercury contamination levels in selected water bodies of the Kambele-Batouri gold mining area were assessed to evaluate the potential of locally produced activated carbon as an adsorbent for mercury removal. Wastewater samples were collected from three strategic locations (upstream, downstream, and wastewater from the mining area). Mercury levels were quantified using a spectrophotometer. The physical parameters of the wastewater samples (pH and hardness) were determined. Activated carbon (AC) was produced from wood and treated with compounds to enhance the mercury adsorption capacity. The results revealed varied mercury concentrations: upstream (0.64 Mg/l), downstream (0.40 Mg/l), and wastewater from company (1.17 Mg/l). 0.5 g and 5 g of activated carbon were employed for mercury remediation from wastewater. The results showed a remarkable potential for mercury removal under laboratory conditions. The 0.5 g of AC had a removal range of 59% to 95%, whereas 5 g of AC had a removal range of 85% to 100%. The adsorption efficiency increased with the contact time, highlighting that the optimization of these parameters can enhance the treatment performance. These findings highlight serious environmental and public health risks associated with mercury use in artisanal and small-scale gold mining communities, as well as their effective removal by AC. Continuous exposure through drinking water and aquatic food chains can lead to bioaccumulation and chronic toxicity in local populations. Immediate intervention measures through the introduction of mercury-free gold-recovery technologies are recommended.