# Presentation: 182537

## INTEGRATED PROCESSES FOR TREATMENT OF BERKELEY PIT WATER

- ACTIVITY III, PROJECT 21

## BACKGROUND

- The Berkeley Pit (Butte, Montana) - is currently filling at a rate of  3 million gallons per day of acidic, metals laden water
- EPA issued a Record of Decision in 1994; the Berkeley Pit will be allowed to fill until approximately 2021, at which time the water level will approach the Critical Water Level

**Notes:**
must be prevented from further rise by pumping and treating water for discharge

## BACKGROUND (cont.)

- Treatment technologies will be revisited approximately 2009; treatment required essentially forever
- ROD designated hydroxide precipitation with aeration (followed by reverse osmosis if necessary) as preferred treatment technology
- Over 1000 tons per day of dewatered sludge will be produced

## PROJECT CONCEPT

- Value of contained metals presents opportunity for offsetting treatment costs via product recovery/resale
- Acid mine drainage a worldwide problem
- Project will evaluate both proven and new technologies for optimizing overall economics of producing compliant water

## PROJECT CONCEPT (Cont’d.)

- All aspects of problem will be included
- Challenges
- Distance of Butte, Montana from markets
- Dilute feed stream (though extremely contaminated)
- Low-value base metals present

**Notes:**
Including  sludge handling/storage)

## CURRENT PROJECT SCOPE

- Develop two optimized flowsheets
- Water Treatment-Only
-  Water Treatment-Plus-Product Recovery
-  If results economically attractive, pursue pilot             testing of optimized product recovery process at Berkeley Pit

**Notes:**
(minimize the cost of producing compliant effluent  water)
(attempt to improve water treatment economics with selected product recovery)

## CURRENT PROJECT SCOPE (Cont’d.)

- Major Tasks
- Prepare standardized cost-estimating methodology
- Develop optimization strategy (identify/prioritize potential process improvements)

**Notes:**
Verify technical/cost aspects of reference flowsheets with which to compare potential improvements
Water treatment: ROD treatment process
Water treatment-plus-product recovery: MSE-developed process 

## PROJECT STATUS AS OF APRIL 2000

- Work plan complete
- Conceptual design of sludge repository complete
- Cost estimating methodology document complete
- Document verifying technical and cost aspects of reference flowsheets complete
- Optimization strategy in development
- Preliminary optimization efforts underway (gathering cost/technical data applicable to both flowsheets)

## PROJECT SCHEDULE

- Final report describing optimized flowsheets due for publication in November 2000

## IMPROVEMENTS IN ENGINEERED BIOREMEDIATION OF ACID MINE DRAINAGE Activity III, Project 24

## Project Objectives

-  Objectives for improvements of engineered
-  features of a passive SRB-bioreactor include:
- Selection of media
- Design of a permeability and contact time enhancing system (PACTES),
- Design of an organic carbon replaceable cartridge system (RCS),
- Development of computer software to _model_ SRB bioremedial processes in the bioreactor.

**Notes:**
with the optimum organic carbon,

## Scope of Work

- The scope of work of the project includes seven tasks:
- _Task I_
- Selection of organic carbon media that:
- is permeable when saturated with water,
- contains sufficient mass of organic carbon to minimize treatment rates, and
- Could be economically used for passive SRB bioreactors.

## Scope of Work, cont.

- _Task II_
-    PACTES design, evaluation through a bench test study, and implementing it in the field.
- _Task III_
-    Designing of an organic carbon RCS that would be easy to install and replace in a bioreactor at a remote location.

## Scope of Work, cont.

- _Task__ __**IV**_
-  Development or adaptation of computer software to model SRB bioremedial processes in the bioreactor.
*This task includes efforts on:*
*Software development and validation*
*Lab experiments for bioreaction kinetics*

**Notes:**
Insomuch, that a designer could efficiently design the bioreactor, and quantify the expected rate of organic carbon depletion.

## Scope of Work, cont.

- _Task V_
-     Implementation of the results of _the _four previous tasks in a bioreactor constructed for this purpose.
- _Task VI_
-     Project management activities.
- Task VII
-     Site selection and characterization

**Notes:**
Task V  - This bioreactor will serve as an ultimate "testing ground" for the final examination of the accomplishments of each task. 
Task VII - if the Calliope site can not be used for the field implementation.

## Status of Work(as of 03/31/00)

- Task I was initiated in February, 2000.
- Data base structure is 60% developed.
- Search of information is advanced approximately 30%.

## SLUDGE STABILIZATION

- Activity IV ; Project 2

## OBJECTIVE

- Formation, properties and stability of sludge generated during treatment of acid mine waste water
- Physically and chemically characterize sludges
- Study the stability of sludges created by treatment techniques
- Apply to acid mine water
- Point source
- Non-point source

## Stabilization Techniques will be Developed for Hazardous Sludge

- Commonly used additives for metallurgical waste solids
- Thermal Processing
- Effective for arsenic bearing waste
- Recovery of metal values or removal of hazardous constituent/recycling to metallurgical processes
- In particular, sulfide sludge

**Notes:**

Three Characteristic Sludges will be generated for further study
Base initiated precipitation
Inorganic Sulfide initiated precipitation
Sulfate reducing bacteria generator sludges

## DEMONSTRATION OF ARSENIC REMOVAL TECHNOLOGY

- Activity IV ; Project 5

## OBJECTIVES

- Remove Arsenic from Solution
- Characterize Solid Products
- Determine Stability During Storage

## CONCEPT

- Produce an apatite mineral-like structure with the substitution of arsenate for phosphate in the structure

**Notes:**
The product of apatite is based on lime precipitation in the presence of phosphate

## REMOVAL OF ARSENIC FROM WASTE SOLUTIONS

- 	WHAT IS WRONG WITH SIMPLE LIME PRECIPITATION??

**Notes:**
COMPOUNDS FORMED ARE NOT STABLE IN OUTDOOR STORAGE PONDS.  THE COMPOUNDS REACT WITH CARBON DIOXIDE IN THE AIR TO FORM CALCIUM CARBONATE.

## EPA’s BDAT FOR As BEARING WASTEWATERS

- Ferrihydrite precipitation is an adsorption phenomena
- Potential Problem
- Long-term storage

**Notes:**
Ferrihydrite is effective for Arsenic, heavy metals.
But the problem is the long-term storage because the ferrihydrite converts to Goethite

## ASARCO DEMO RESULTS

- Scrubber Blowdown Water
- >3,000,000 ppb As to <10ppb As
- Thickener Overflow
- 6,000 ppb As to <15 ppb
- Long-term Aging Presently Being Conducted (ASARCO and Mineral Hill Products)

**Notes:**
For long term aging: pH, Eh is measured monthly; solubility of solids is measured at 2 years; structure is evaluated at 1, 1.5, and 2 years.

## MINE WASTE BERKLEY PIT LAKE CHARACTERIZATION PROJECT

- Activity IV ; Project 8

## CHARACTERIZATION PROJECTS

- DEPTH PROFILES
- ORGANIC CARBON
- SRB ACTIVITY IN SEDIMENTS
- SURFACE WATER REACTION KINETICS

**Notes:**
DEPTH PROFILES: PH, TEMPERATURE,METALS,DISSOLVED OXYGEN ARE EVELUATED AT DIFFERENT DEPTHS
ORGANIC CARBON: DETERMINE THE TYPES AND AMOUNTS OF ORGANIC CARBON IN BERKLEY PIT WATER
RESULTS:ORGANIC CARBON HAS BEEN FOUND BUT THE EXACT SOURCE HAS NOT BEEN IDENTIFIED
TOC WITH DEPTH
SRB ACTIVITY: DETERMINE IF SRBS EXIST IN THE SEDIMENTS AND IF THEY CAN BE USED FOR REMEDIATION
RESULTS: NO SRBS ACTIVITY NOTICED AND NO SRBS WERE IDENTIFIED
SURFACE PROFILE: TO UNDERSTAND AND DUPLICATE IN THE LAB THE CONDITION THAT OCCURS IN TOP FEW METERS OF THE BERKLEY PIT WATER
RESULTS: SURFACE PROFILES WERE DUPLICATED; UV LIGHT HAS SOME EFFECT ON SURFACE WATER REACTIONS

## SUMMARY

- Berkley Pit Lake system is complex and requires much more research to fully understand
- Knowledge gained through work on Berkley Pit may be used on other pit lakes through out the world

## Artificial Neural Networks As An Analysis Tool for Geochemical Data

- Activity IV ; Project 14

## WHY USE NEURAL NETWORK?

- TO SORT THROUGH OR ANALYZE VERY LARGE
- DATA VOLUMES
- NN’s basically think like the human brain

**Notes:**
LIKE THE HUMAN BRAIN, BUT ARE CAPABLE OF LOOKING AT MULTIDIMENSIONAL DATA WHEN ANALYZING CHARACTERISTICS OF THAT DATA - -  THE BRAIN CAN USUALLY HANDLE 2 OR 3 DIMENSIONAL DATA

## ALGAL REMEDIATION DATA OF BERKELEY PIT

- 4 Classes of Data with 15 Samples
- Within each class, 5 subclasses exist with 3 samples each

**Notes:**
This is a good example for Neural Networks

## Self- Organizing Map

- Groups Data According to Trends Within the Data
- For Algae, the SOM Output Compared to Known Data Classes
**NOTE:  Neural Networks can also be used to predict data**

**Notes:**
For Algae – to analyze the types of trends found; if NN is reliable (90-95% accurate), unknown data may be classified

## Future Possibilities for NN Analysis of Algae

-  Look for behavior trend within Algae species
- Compare similarities and differences
- Train network to recognize different Algae species and concentrations
- Develop network to predict Algae types and concentrations from pit-water metal concentrations