Technologies for boron removal

Boron has been widely used in various manufacturing industries, and the level of boron in the industrial effluent can range from as high as several grams per liter to as low as a few micrograms per liter. Due to the potential adverse health effect of boron on human beings, the World Health Organization (WHO) has provided a guideline for the boron concentration in drinking water to be less than 0.5 mg/L. Therefore, the boroncontaining effluents or solutions should be treated before they could be discharged into natural water bodies. This paper critically reviews various technologies used for boron removal, including those recently developed, electrocoagulation (EC) and double-layered hydroxide (DLH) compounds, as well as conventional and advanced treatment technologies such as chemical precipitation, ion exchange, reverse osmosis, adsorption, liquidliquid extraction, and electrodialysis.