Sustainable and Environmentally Friendly Water Treatment Solutions at the Revenue-Virginius Mine

Transcription

1 Sustainable and Environmentally Friendly Water Treatment Solutions at the Revenue-Virginius Mine Katie Schumacher October 4, 2018

2 Agenda Mine water management Existing system at the Revenue-Virginius Mine Proposed process flow diagram for Mine Pilot system overview Treatability testing summary Preliminary results Recommendations

3 Mine Water Management Mine start-up Regulatory compliance San Juan mining challenges Multiple stakeholders

4 Existing Mine Water Pond

5 Existing Bioreactor

6 Process Flow Diagram Coagulant Addition Portal Water Mine Water Pond Transitional Passive Filter Pond #2 Bioreactor Channel/ Pipeline Aerobic System Pond #3 Aerobic Wetland Discharge to Sneffels Creek

7 Passive Treatment Systems Sulfate-reducing bioreactor (SRB) Constructed Aerobic Wetland Sources: Interstate Technology Regulatory Council and EPA Reference Guides for Passive Treatment Technologies for Mining-Influence Water

8 Revenue Silver Mine Process Flow Diagram

9 Bench-Scale Jar Testing

10 Pilot System MRI Unit to test MWP Aerobic Wetland Units

11 Pilot System SRB Unit Anaerobic Wetland

12 Concentration (mg/l) Example Metal Removal Performance Dissolved Cd System Snapshot Week of 04/02/18 Week of 04/30/18 Week of 05/28/18 Week of 06/25/18 30-Day Avg Permit Limit 0 F2 B1 B2 B3 B4 Sample Location F2 Outlet of MWP B1 Outlet of Aerobic Wetland 1 B2 Outlet of SRB B3 Outlet of Anaerobic Wetland B4 Outlet of Aerobic Wetland 2

13 Concentration (mg/l) Example Metal Removal Performance 6 Dissolved Zn System Snapshot Week of 04/02/18 Week of 04/30/18 Week of 05/28/18 Week of 06/25/18 30-Day Avg Permit Limit 0 F2 B1 B2 B3 B4 Sample Location F2 Outlet of MWP B1 Outlet of Aerobic Wetland 1 B2 Outlet of SRB B3 Outlet of Anaerobic Wetland B4 Outlet of Aerobic Wetland 2

14 Concentration (mg/l) Sulfate Reduction Performance Sulfate System Snapshot Week of 04/02/18 Week of 04/30/18 Week of 05/28/18 Week of 06/25/18 0 F2 B1 B2 B3 B4 Date F2 Outlet of MWP B1 Outlet of Aerobic Wetland 1 B2 Outlet of SRB B3 Outlet of Anaerobic Wetland B4 Outlet of Aerobic Wetland 2

15 ORP (mv) ORP Performance ORP Snapshot F2 B1 B2 B3 B4 Sample Location 5/1/2018 5/15/2018 5/24/2018 6/14/2018 7/3/2018 F2 Outlet of MWP B1 Outlet of Aerobic Wetland 1 B2 Outlet of SRB B3 Outlet of Anaerobic Wetland B4 Outlet of Aerobic Wetland 2

16 Pilot System Results Proof of concept was confirmed for removal of Cd, Fe, Pb, and Zn Results for Train A and Train B mirrored each other Low DOC in effluent of bioreactors Biopolymer formed in effluent of bioreactors

17 Preliminary Findings at 4 Months Cold influent water (6-10 C) impacted biological performance Final aerobic wetlands were not able to reoxygenate Potentially clogged due to biopolymer formation Acted as sand filter So we ve achieved proof of concept on the bench and pilot scale under low-flow conditions what next?

18 Challenge Testing Aeration channel at end of pilot High flow rates through system Effect of abrupt stop of flow through system Clarification testing

19 Clarification Unit

20 Takeaways and Recommendations Preliminary phase of data analysis Treatability testing on the bench- and pilot-scale provides valuable insight for full-scale design Passive water treatment solution Long-term sustainable water management treatment Minimize impacts in a recreation area Hybrid design to manage variable flow and highflow risks to achieve compliance 5-step treatment design Multiple barrier approach

21 Questions? Katie Schumacher Geosyntec Consultants Direct: