Volume 5, Issue 10 (November 2008)
A Review on Advanced Treatment Methods for Arsenic Contaminated Soils and Water
A number of treatment methods have been investigated in the laboratory or full scale to remove arsenic from drinking water and to remediate arsenic-contaminated sites. This paper gives a review on the advanced technologies for the treatment of arsenic-contaminated soils and water. Treatment methods such as oxidation, anion exchange, membrane separation, and adsorption/precipitation have been developed to remove arsenic from drinking water or groundwater. However, further research is needed to find new and more efficient substitute materials for the ion exchange resins, membranes, and adsorbents to improve the treatment and cost efficiencies. A stabilization/solidification method has been demonstrated successfully to contain arsenic in contaminated soils, sediments, and solid wastes. Vitrification is also applicable but may be more expensive due to the high energy requirements. Electrochemical methods based on electrokinetics are emerging. Especially, electrokinetics and electrodialysis are suited for fine-grained soils. Chemical extraction, either in-situ or ex-situ, can be efficient to remove bulk arsenic from contaminated soils and solid wastes. Selection of proper extractants is the key to the success of this method. Bioremediation, phytoremediation, and natural attenuation show great potential for future developments because of their environmental compatibility and cost effectiveness. Generally, it is critical to recognize that no single specific technology may be considered as generally applicable. Combination of existing technologies may provide an efficient and cost-effective treatment alternative. Use of biodegradable and environmentally benign products to enhance the remediation processes should be further investigated.