|
||
|
||
| April 19, 2024 | ||
| Search |
| Current Training |
By Course Title |
| Course Catalog |
| By Course Title By Training Partner By Delivery Method |
| Students |
View Registrations/Transcripts |
| About Trainex |
| Overview Contact Us Help! |
| OLEM Training Coordination Team |
| Locate
Team Members Regional/State Training Brochure |
| Other Training Resources |
| EPA Other U.S. Government |
Internet-based seminar
| Hosted by U.S. EPA |
Two laboratory-scale packed bed column experiments were conducted to study the impact of ZVI on the treatment of acid rock drainage by sulfate reduction, imitating a biologically active permeable reactive barrier (PRB). A control column was packed with a compost and limestone mixture. A complete treatment reactor was composed of a compost, limestone and ZVI mixture (ZVI 10% by volume). Both reactors were inoculated with a mixed culture containing sulfate reducing bacteria. The reactors were fed with a synthetic acid rock drainage (SARD) containing 250 mg/l of sulfate and copper (10 to 25 ppm). The SARD was fed at a hydraulic retention time of 24 h. Initially the pH of the synthetic acid rock drainage was set at 7; however. the pH of this influent was progressively decreased to 3 so as to imitate the severely acidic conditions of real acid rock drainage.
The complete treatment with ZVI provided: two-fold greater levels of sulfate reduction while discharging 3-fold less sulfide compared to the control reactor. Sulfide formed in the ZVI-containing reactor was thus effectively precipitated as FeS. The ZVI containing column had effluent pH values that were on the average 3 units higher compared to the effluent of the control reactor lacking ZVI, emphasizing the large impact of ZVI on generating additional alkalinity. During the operation of both columns, copper was effectively removed. The copper removal efficiency was 96.8% (±1.1) and 93.4% (±2.2) in the treatment and control columns, respectively.
The results taken as a whole clearly indicate that inclusion of a small percentage of ZVI in the PRB greatly increased the increased sulfate reduction, decreased release of sulfide, and produced more alkalinity compared to the control column. This was achieved while maintaining nearly complete removal of copper. For general information contact Justin Crane by telephone at 919 794-4702
| Upcoming Events No upcoming events. Archives of past CLU-IN internet seminars are available in the CLU-IN Studio at http://clu-in.org/studio/. You will be able to view the slide and hear an audio stream of the presentation as it occurred.  |
Previous Events (click to view/hide)
|
Live Online Class, Internet Based 
