Removal of Silver (Ag) from Artificially Contaminated Soil Using Acetic Acid as Electrolyte with Electrokinetic Remediation

Abstract

The electrokinetic remediation of artificially silver (Ag) contaminated soils was evaluated. In this study, the soil sample was taken from locations A and C near silver handicraft workshop assuming has similar natural geochemistry with silver contaminated soil. While control soil was taken from locations B and D at Kotagede, Yogyakarta, Indonesia. All soil samples were contaminated with a silver (100 mg AgNO3/Kg soil) and they were treated in six cycles of saturation process using deionized water and air-dried before being aged for one year and subjected to electrokinetic (EK) remediation treatment. The physical and chemical properties of soil were measured using flame atomic absorption spectrophotometric. Soil components such as organic matter, total nitrogen, CEC, soil texture, and soil buffer capacity were also evaluated. Desorption of silver with different acetic acid concentrations (i.e 0.1, 0.5, 1.0 and 1.5 M) was also studied in a batch system. Electrokinetic remediation treatment was conducted by a graphite electrode in a constant voltage of 1 Vcm-1 for 7 d. The current flow during EK remediation treatment was recorded by data logger for every 10 mints. The results showed that high removal of silver from soil was achieved when using 1.0 M acetic acid as the electrolyte. In this regard, the EK remediation treatment could achieve high silver removal from soil A (92 to 93%) and soil C (82 to 92%) compared with soil B (75 to 96%) and soil D (26 to 74%), respectively.