|
Application of Phosphate and EDTA on As(V) Removal in Gold Mine Tailings by Electrokinetic Remediation |
|---|---|
| รหัสดีโอไอ | |
| Creator | 1. Udomsak Boonmeerati 2. Pantawat Sampanpanish |
| Title | Application of Phosphate and EDTA on As(V) Removal in Gold Mine Tailings by Electrokinetic Remediation |
| Publisher | Thai Society of Higher Education Institutes on Environment |
| Publication Year | 2563 |
| Journal Title | EnvironmentAsia |
| Journal Vol. | 13 |
| Journal No. | 3 |
| Page no. | 1-12 |
| Keyword | Arsenic, Gold mine tailing, Electrokinetic remediation, Phosphate, EDTA |
| URL Website | http://www.tshe.org/ea/index.html |
| Website title | EnvironmentAsia |
| ISSN | 1906-1714 |
| Abstract | The use of phosphate and/or EDTA to enhance the removal of arsenate (As(V)) from gold mine tailings by electrokinetic remediation (EKR) was investigated. The effect of different concentrations of phosphate or EDTA on As (50 mg/L) movement was first evaluated in a two-layered agar matrix with EKR at 2 V/cm for 72 h. Subsequently, the assay was repeated for As-contaminated mine tailings (60 mg/kg), by applying the EKR for 168 h and using the additive concentrations that gave maximal levels of As at the anode. The upper 10-cm layer of agar was uncontaminated, while the lower 10-cm layer was contaminated with As with or without the added phosphate (P) and/or EDTA (E) at 25, 50, or 75 mg/L of agar. The As was translocated and accumulated at the anode at higher levels in the presence of 50 mg/L of phosphate (P50) or EDTA (E50) than in the control. With the addition of P50, the As level increased in the upper layer, whereas with E50 the As mainly accumulated in the lower layer. The co-addition of both P50 and E50 (P50/E50) led to As accumulation in both the upper and lower layers at essentially the same level. The pH, Eh, and EC in the tailing under EKR changed less in P50 and E50 than in the control, but differed between each other. P50 supplementation caused As to accumulate at the anode by electromigration, whereas in the control As migrated to accumulate at the cathode and also in-between the cathode and anode by electro-osmosis. In contrast, E50 and the combined P50/E50 addition did not result in a significant As concentration in each zone, but showed a trend of a decreased concentration at the cathode. |
