Analytical survey of arsenic in geothermal waters from sites in Kyushu, Japan, and a method for removing arsenic using magnetite

Abstract

The objective of this study was to survey the cation and anion contents of geothermal waters to gather fundamental information on geographical variations. Sixteen sites in hot spring areas on the island of Kyushu in Japan were studied. The study focused on the arsenic content of the samples. Very high arsenic concentrations (more than 0.1 mg/l) were detected in most of the geothermal waters sampled. High contents of boron and fluoride (more than 1.0 mg/l) were also detected in some samples. Arsenic removal was performed on a laboratory scale using columns packed with a magnetite-type adsorbent. The reduction of arsenic contamination to a concentration of less than 0.01 mg/l could be achieved in the early stages of adsorption (bed volume = 200).

Arsenic and fluoride contaminated groundwaters: A review of current technologies for contaminants removal

“…Very high concentrations of As can be seen predominant in Mexico, USA, China, Bangladesh, Vietnam and Pakistan. Recently, groundwaters in Japan and Korea were also found to be contaminated with As (Ahn, 2012;Yoshizuka et al, 2010). The major mechanism responsible for the As contamination in groundwater is desorption from iron oxides or hydroxides from natural rocks and their reductive dissolution (Kim et al, 2012;Li et al, 2012).…”

Environmental Geochemistry of Potentially Toxic elements in thermal springs in the Sabalan Volcanic Field, NW Iran

“…Thermal springs are usually enriched in some potentially toxic elements inherited from the same hydrothermal reservoir. According to Smedley and Kinniburgh (2002), and Yoshizuka et al (2010), arsenic is a ubiquitous and persistent element found in volcanic gases and emanations. It is estimated that about 1.9 Gg arsenic are annually released to the atmosphere by volcanoes (Nriagu 1989).…”

Adsorption of Arsenic by Fe3O4, TiO2, and Al2O3 Adsorbents

“…1) Geothermal water contains a variety of valuable minerals, such as lithium (～10 mg/dm 3 ) and boron (～30 mg/ dm 3 ), as a result of hot leaching from the rocks in the aquifer by geothermal water. 2 5) The geothermal water has, however, a disadvantage that high concentration of arsenic is also contained.…”

“…These results are entirely consistent with our previous research. 21) Considering the pH value of geothermal water (around 6 8), 1) all the adsorbents are applicable for As removal, especially As(III) having higher toxicity than As(V), from geothermal water. Based on the batchwise adsorption, the column operation for aqueous solution containing As(III) was conducted.…”