Arsenic Remediation from Water in Burkina Faso Using Local Materials as Adsorbents: Overview, Mitigation and Prospects

In Burkina Faso, arsenic is one of pollutants which affect the quality of water and food, mainly the vegetables. To mitigate this arsenic pollution, it is important to develop a cheap and efficient technology using a mixture of adsorbents, which is eco-friendly and cost-effective and based on laterite soils. The present study aimed to contribute to the development of an effective method for the treatment of arsenic contaminated water using the local materials. Batch experiments were carried out for arsenic removal using As(V) aqueous solutions. Experimental results indicated an improvement of removal capacity of new material and the yield of water treatment increased. Indeed, the increase of flow rate caused a decrease in the efficiency of the water treatment from 98.25 to 88.14% while the increase in the mass of doped laterite showed an increase in the service times. From column experiments, best efficiency (≈99%) in arsenic removal was obtained for pH values between 3 and 5 with a flow rate of 9 mL/min and 12 g of doped laterite. From batch studies, the mechanism of As(V) removal was described by a physico-chemical adsorption following pseudo-second order kinetic. The adsorption capacity of doped laterite (0.83 mg/g) was higher compared to the one of natural laterite (0.79 mg/g) indicating the better efficiency of doped laterite. Consequently, the doping of laterite increased the iron content which is responsible of high arsenic removal regarding the affinity iron-arsenic.