As and Sb speciation in relation with physico-chemical characteristics of hydrothermal waters in Java and Bali

The distribution and geochemical behavior of As and Sb redox couples in hydrothermal waters from Bali and Java, Indonesia were investigated. Simultaneous speciation analysis of As and Sb was carried out using SF-ICP-MS coupled to HPLC. The concentration and distribution of As and Sb were closely related to host rock-water interaction and water types (Cl-rich, SO4-rich and HCO3-rich), e.g. in HCO3-rich samples, As(V) was the main form. Arsenic concentrations on Java were generally much higher (up to 9220.83 mu g L-1) than those from Bali (with the highest concentration of < 40 mu g L-1). In five samples (B1, B2, B3, B7 and J1), an unknown As species was detected. In B7 and J1, the unidentified species was even dominant, probably due to the involving of seawater feeding. Antimony concentrations were generally two orders of magnitude lower than As. In addition, Sb was less mobile than As, and Sb species were much easier affected by various processes after discharge, e.g. adsorption and/or (co-) precipitation. Noteworthy, in J1 and J2 extremely high concentration of Cl was detected (8671.8 mg L-1 for J1 and 5948.7 mg L-1 for J2), and As and Sb distributions were found of significant difference. (C) 2016 Elsevier B.V. All rights reserved.