Separation of Boron and Arsenic from Geothermal Water Using a Glucamine-Based Chelate Adsorbent

Abstract

Geothermal water contains several important metals, and the separation and recovery of these elements from the geothermal water has attracted interest. However, geothermal water also contains harmful elements, such as boron (B) and arsenic (As), that need to be removed. In the present work, separation of B and pentavalent As(V) from geothermal water was investigated using a glucamine-based chelate fiber as an adsorbent. In single-metal systems, the adsorption of B was high in the neutral pH region, while the adsorption of As(V) was high in the acidic pH region. In a B/As(V) binary system, adsorption of boron at acidic pH was inhibited by the presence of As(V). The adsorption isotherms of the metals in the single-metal systems at three different equilibrium pH values were of the Langmuir type. The adsorption isotherms in the B/As(V) binary system were described by a modified Langmuir model, which indicated that the adsorption was inhibited or promoted by the co-existing metals. Simultaneous removal of the metals from geothermal water was achieved by column adsorption.

Keywords

• Boron
• Arsenic
• Geothermal water
• Adsorption
• Separation