Nutrient and Sulfide Export From aMine Drainage Passive Treatment System

S.A. Yepez & R.W. Nairn29th Annual Meeting of the American

Society of Mining and ReclamationJune 13, 2012

Results

Methods

Introduction

Conclusions

Introduction

Introduction

• Mine drainage – water and oxygen react with rock in mine void

• Elevated metals and sulfate

• Passive treatment system (PTS)

Nuisance Constituents

• Additional impacts – not typically monitored

• “Nuisance constituents” – potentially harmful concentrations of non-target contaminants

• Nutrient and sulfide export

Nuisance Constituent Impacts

• Nutrients, sulfide degrade water quality

• Eutrophication leads to algal blooms

• Algal senescence can impact treatment

MRPTS polishing wetland, 02/2009

Literature Review

• Potential for nuisance constituent export from vertical flow bioreactors

• Export/removal varies with treatment process

Research Objective

• Determine nuisance constituent (nutrient and sulfide) inputs and outputs of each cell of a PTS

• Hypothesis: nuisance constituents seasonally exported by PTS

Methods

Study Site: Mayer Ranch Passive Treatment System (MRPTS)

OXSF

VFRA

LBPW

Photo taken 09/2011

Nuisance Constituent Analysis

• Sampling: Fall 2010-Summer 2011

• Major species of N and P, total sulfide, metals

• Mass balance to determine export

• Plotted for seasonality

• Algal study of polishing wetland

Results

Target Contaminant RemovalSampling site ------------------Loading rate (g/d)------------------

As* Cd* Fe Pb* ZnSeep A 17.8 2.99 31,200 22.0 2,090Seep B 35.5 6.48 66,600 46.0 4,180Seep D 3.97 0.71 7,240 4.95 509Total inflow 57.2 10.2 105,000 73.0 6,770Outflow 7.29 0.25 479 11.9 88.0System removal 51 9.94 105,000 61.1 6,690

*Effluent concentrations below detection limit; 1/2 value of practical quantification limit used for mass balance calculations

Nuisance Constituent Status

Constituent System Effluent (mg/L) Effluent Criteria (mg/L) SourceTotal Nitrogen 0.30—1.01 ± 0.26 0.36 (lakes), 0.69

(streams)EPA, 2000

Total Phosphorus 0.03—0.59 ± 0.14 0.020 (lakes), 0.037 (streams)

EPA, 2000

Total Sulfide <0.5—3.4 (about 40% H2S) 0.002 as H2S EPA, 1986

Nutrient Export------------------TP (g/d)------------------ ------------------TN (g/d)------------------

Fall Spring Summer Fall Spring Summer

Influent 1,180 1,890 1,060 491 565 456

OX export -1,160 -1,830 -1,010 -344 -163 -286

SF export -10 -19 -33 -49 40 -78

VF export 38 46 62 54 -123 77

RA export -7 -24 11 77 -127 20

LB export -19 -11 52 31 -16 50

PW export -26 -13 -2 -64 55 30

Effluent 21 72 283 195 232 509

Net export -1,160 -1,810 -777 -296 -333 53

Total Nitrogen

Inflow OX out SF out VF out RA out LB out PW out0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40 Fall 2010Spring 2011Summer 2011

[TN

] (m

g/L)

Total Phosphorus

Inflow OX out SF out VF out RA out LB out PW out0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50 Fall 2010

Spring 2011

Summer 2011

[TP]

(mg/

L)

Seasonal Removal

Seasonal Export

Removal

Seasonal Export

Seasonal Export

Seasonal

Export

Nitrogen Processes - MRPTS

Phosphorus Processes - MRPTS

Removal

ExportRemoval

Seasonal Removal

Removal

Removal

Polishing Wetland Eutrophication

• N:P ratio 1.15:1• Blue-green algae

dominated• Genera Lyngbya,

Anabaena• Dominant diatom

genera: Nitzschia, Navicula

Potential Treatment Impacts

• BGA not widely grazed by zooplankton

• Algal senescence impedes re-aeration

• Some Anabaena are N2-fixers

• Anabaena produce neurotoxins, hepatoxins, foul odors

Total Sulfide Export---------------------Total Sulfide (g/d)---------------------

Fall Spring Summer

Influent --- --- 132*

OX export --- --- ---

SF export --- --- ---

VF export 1,460 1,670 6,020

RA export -1,380 -1,620 -2,430

LB export -83 -53 -214

PW export --- --- -5,860

Effluent --- --- 1,000

Net export appx. 0 appx. 0 868

*Influent BDL; ½ detection limit used for mass balance

Total Sulfide

Inflow OX out SF out VF out RA out LB out PW out0.0

5.0

10.0

15.0

20.0

25.0

30.0

Fall 2010

Spring 2011

Summer 2011

[Sul

fide]

(mg/

L)

Sulfide Processes - MRPTS

Export

Removal

Removal

Seasonal Removal

N/A

N/A

Conclusions

Nuisance Constituent Export

• All constituents exported by at least one treatment process

• All constituents demonstrated seasonality

• Hypothesis supported

Future Studies

• Nuisance constituent processes within cells

• Changes in nuisance constituent concentrations over system lifetime

• Nuisance constituent mitigation in PTS design

Acknowledgments

• Funding: American Society of Mining and Reclamation, Grand River Dam Authority, University of Oklahoma

• Center for Restoration of Ecosystems and Watersheds: B. Furneaux, J. LaBar, L. Oxenford

• Grand River Dam Authority: R. Simmons, S. Ziara• Oklahoma Biological Survey: L. Bergey, N. Desianti• University of Oklahoma Biological Station: K. D. Hambright, K.

Glenn, T. Ward• Local Environment Action Demanded: Rebecca Jim

Literature CitedU.S. Environmental Protection Agency (EPA). 2000. Ambient water quality recommendations: information supporting the development of state and tribal nutrient criteria, rivers and streams in Nutrient Ecoregion IX. Office of Water, Washington, D.C. EPA 822-B-00-019. http://water.epa.gov/scitech/swguidance/standards/criteria/nutrients/upload/2007_09_27_criteria_nutrient_ecoregions_rivers_rivers_9.pdfU.S. Environmental Protection Agency (EPA). 1986. Quality criteria for water: 1986. EPA 440/5-86-001. http://water.epa.gov/scitech/swguidance/standards/criteria/aqlife/upload/2009_01_13_criteria_goldbook.pdfU.S. Environmental Protection Agency (EPA). 1984. Protection of Environment: Secondary Treatment Regulation. 40 CFR 133.102. http://cfpub.epa.gov/npdes/npdesreg.cfm?program_id=45

Questions?