Treatment of Geothermal Water from Geothermal Plant using Hydrotalcite for Removal of Harmful Anions

摘要

We tried to remove harmful anions (As, B and Si) from geothermalwater using hydrotalcite. Non-calcined hydrotalcite and calcinedhydrotalcite was used to remove anions from geothermal waterobtained from the Sumikawa geothermal plant in Japan. Calcinedhydrotalcite indicated more effective removals of harmful elementsthan non-calcined hydrotalcite. Using calcined hydrotalcite, theconcentrations of As and B dropped to below Japanese effluentstandard level (0.1 mg/L and 10 mg/L, respectively), and silicaconcentrations the level to prevent silica scale (100 mg/L), respectively.These removal abilities are almost constant in the range of temperaturebetween 25 ℃ and 80 ℃.