all about discovery! new mexico state university situ ... · all about discovery! new mexico state...

All About Discovery!New Mexico State University

nmsu.edu

™

Rapid and in‐situ analysis of metal concentrationsin agricultural fields in San Juan County using

Portable X‐ray fluorescence (PXRF)

Gaurav JhaDepartment of Plant and Environmental Sciences

All About Discovery!New Mexico State Universitynmsu.edu

™™

Basic Principle of PXRF

Applications in environmental

sciences

Extension and Outreach

Response to GKM spill


™™

• Soil scientists have long differentiated

soils based on chemical properties.

Pedocal

Pedalfer

Curtis Marbut’sNormal Soil concept

• Soil scientists have long differentiated

soils based on chemical properties.

Curtis Marbut’sNormal Soil concept


™™

• Historically, many chemical

determinations were made

via titration or colorimetry.

• More recently, lab based

instruments have offered

greater accuracy

• ICP-AES/MS

• AAS

Rapid

Large number

of samples

Cost Effective


™™

http://www.sun.org/encyclopedia/electromagnetic-spectrum

The colors we see!


™™

Working Principle of PXRF

Activation of X-Ray Tube

Sample Excitation

Fluorescence

Capture Spectrum

Results

https://www.olympus-ims.com/en/xrf-xrd/delta-handheld/delta-mining/#!cms[tab]=%2Fxrf-xrd%2Fdelta-handheld%2Fdelta-mining%2Fapplications

http://www.equipcoservices.com/support/tutorials/introduction-to-xrf-spectrometry/

https://www.olympus-ims.com/en/applications/portable-xrf-technology-archaeometry-authentication-conservation-art-objects/


™™

Specifications for GKM sample analysis

• X Ray tube operated at 10-40 keV. Not an active source of radiations.

• Standards: Stainless steel ‘316’ alloy chip• 16.13% Cr

• 1.78% Mn

• 68.76% Fe

• 10.42% Ni

• 0.20% Cu

• 2.10% Mo

• Verified by NIST soil standards

• Scan time- 90 seconds for three beams (30 seconds per beam)

• Instrument is operated in proprietary standard configurations :

1. Geochem mode

2. Soil mode

3. Mining mode


™™

Note-PXRF reports total elemental concentration; not ionic species (e.g.

Fe+2 vs. Fe+3) or compounds (gypsum, calcite, etc.)


™™

Disadvantages

• Cannot determine H,C or Na

• Soil heterogeneity (example Fe and Mn concretions)

Advantages

• Portable

• Simple, non-destructive analysis

• Rapid (90 sec scan)

• Multi-element analysis

• Low limit of detection and wide dynamic range


™™



sciences


™™

On-site metal determination via PXRF

• Heavy metal content

• Sediment and soil spatial analysis

• Plant tissue analysis

• Water analysis

Site specific proxy-determinations of soil parameters via PXRF

• Soil cation exchange capacity (CEC)

• Soil pH

• Soil salinity


™™

Proxy-determinations of soil CEC via PXRF

• CEC is directly associated with soil fertility.

• Lab methods are very accurate but

arduous.http://scienceofagriculture.org/ch-cation.php

Sharma et al. (2015)

• In-situ prediction of soil CEC to develop a

predictive model based on enhanced lab

based data.

R2 = 0.908


™™

Proxy-determinations of soil pH via PXRF

• PXRF cannot read Hydrogen ion directly.

• Soil system pH is commonly associated with

other elements.

Alkaline system-Ca, Mg

Acidic system-Al, Fe

• These elements can be used as a proxy for pH

determination specially where traditional

sampling is not possible-frozen and lithified soils.

https://cosmosmagazine.com/climate/what-happens-if-permafrost-disappears

https://maui-mike.smugmug.com/keyword/lithified%20sand%20dunes/

https://www.uidaho.edu/cals/soil-and-water-systems/research/pedology-laboratory/fosberg-monoliths


™™



sciences



™™


™™

https://i.kinja-img.com/gawker- edia/image/upload/c_ scale,fl_progressive,q_80,w_800/13755 78641640044175.jpg


™™

• Monitor selected metal concentrations in agricultural fields and crop grown within the Animas and San Juan River watershed.

• Characterize spatial variability of selected metals

Gold King Mine Spill- A case study using PXRF


™™


™™

Sampling sites with increasing distance from the GKM (Colorado and NM border through Shiprock)

ColoradoNew Mexico

Shiprock

FarmingtonBloomfield

Aztec

Sampling locationsP

FV

P F V

Pasture (Grass) Forage (Alfalfa) Vegetables


™™

On-site Metal determination for soil spatial analysis

Total Arsenic concentration (parts per million)


™™

What we observed?


™™

Metal RSL (mg kg-1)

Concentration (mg kg-1) in

Pasture land

Concentration (mg kg-1) in Forage land

Concentration (mg kg-1) in

Vegetable Field

Arsenic 7.07 7.19 6.92 7.13

Lead 400 83.28 48.09 17.50

Calcium - 10450 16609 37006

Zinc 2300 223.46 116.64 71.47

Copper 310 38.98 29.43 21.35

Manganese 180 874.92 545.04 312.84

Iron 5500 23838 23160 22860

Average total metal(loid) concentrations (mg kg-1) in fields irrigated by Animas river water


™™

Spatial distribution of Arsenic in agricultural fields

Pasture grass

14.1 hectares

Aztec

Forage (alfalfa)

3.04 hectares

Farmington

Vegetables1.27 hectares

Shiprock

Total Arsenic concentration

(parts per million)

RSL-7.07 mg kg-1


™™

Spatial distribution of Manganese in agricultural fields

Pasture grass

14.1 hectares

Aztec

Forage (alfalfa)

3.04 hectares

Farmington

Vegetables1.27 hectares

Shiprock

Total Manganese concentration

(parts per million)RSL-180 mg

kg-1


™™

Soil Arsenic and Plant growth

• Environmental toxin.

• Inhibits root proliferation and extensions.

• Slows expansion and biomass accumulation.(Finnegan et al, 2012)

https://edu.glogster.com/glog/arsenic/2dxuahjh3rg

http://arsenic-33.narod.ru/groundwater-arsenic-contamination-in-west-bengal-india.html

Keratosis

Hyperaccumulation Into Food chain

https://www.aljazeera.com/indepth/features/2016/01/indias-arsenic-belt-water-project-brings-relief-160128090612395.html


™™

Metal Conc. (mg/kg)

35

ND

ND

82

50

3

78

6334

13

CORN

MetalGuideline value

(mg/kg)

Al 7-3410

As 1.7

Cr N/A

Fe 48

Mn 300

Pb 10

Zn 150

Ca N/A

Cu 30

Leaves

Soil

Corn Cob

Designed by-Mathews A.


™™

Metal Conc. (mg/kg)

406

0.5

ND

387

30

3

32

51955

8

Metal Guideline value (mg/kg)

Al 7-3410

As 1.7

Cr N/A

Fe 48

Mn 300

Pb 10

Zn 150

Ca N/A

Cu 30

WATER MELONS

Soil

Leaves Melon



™™

Metal Conc. (mg/kg)

397

0.9

ND

355

33

ND

33

65650

10

SQUASH

Metal Guideline value (mg/kg)

Al 7-3410

As 1.7

Cr N/A

Fe 48

Mn 300

Pb 10

Zn 150

Ca N/A

Cu 30

Soil

Leaves

Honeydew

HONEYDEW



™™



sciences


Extension and Outreach


™™

Scanning contaminated river sediment samples using VisNIR and PXRF at Indian Institute of

Technology (India)


™™

Conclusions

• Portable X-Ray Fluorescence is a rapid, in-situ and non-destructive

technique for site specific proxy determination of soil properties and total

concentration of metal content.

• Exceeded As and Mn total concentration at some of the hotspots in the fields

across Animas and San Juan watershed did not correspond to the increased

concentration in leaf tissue of plants.

• Metal analysis using PXRF helped to respond quickly when GKM spill

happened and also to reach the farmers and growers at teach-in, radio talks

and through factsheets.


™™

References• Peason D., Weindorf, D.C., ., Chakraborty, S, Li B., Koch J., Deventer P.V.. 2018. Analysis of

metal-laden water via PXRF. Journal of Hydrology 561, 267-276• Sharma, A., Weindorf, D.C., Man, T., Aldabaa, A.A.A., Chakraborty, S., 2014. Characterizing

soils via portable X-ray fluorescence spectrometer: 3. Soil reaction (pH). Geoderma 232–234, 141–147.

• Weindorf, D.C., Paulette, L., Man, T., 2013. In-situ assessment of metal contamination via portable X-ray fluorescence spectroscopy: Zlatna, Romania. Environ.Pollut. 182, 92e100.

• Weindorf, D.C., Bakr, N., Zhu, Y., 2014. Advances in portable X-ray fluorescence (PXRF) for environmental, pedological, and agronomic applications. Adv. Agron.128, 1e45.

• Weindorf, D.C., Zhu, Y., Haggard, B., Lofton, J., Chakraborty, S., Bakr, N., Zhang, W., Weindorf, W.C., Legoria, M., 2012b. Enhanced pedon horizonation using portable Xrayfluorescence spectroscopy. Soil Sci. Soc. Am. J. 76 (2), 522–531.http://dx.doi.org/10.2136/sssaj2011.0174.

• Weindorf, D.C., Zhu, Y., McDaniel, P., Valerio, M., Lynn, L., Michaelson, G., Clark, M., Ping, C.L., 2012c. Characterizing soils via portable X-ray fluorescence spectrometer: 2. Spodicand Albic horizons. Geoderma 189–190, 268–277. http://dx.doi.org/10.1016/j.geoderma.2012.06.034.

• Weindorf, D.C., Herrero, J., Bakr, N., Swanhart, S., 2013a. Direct soil gypsum quantification via portable X-ray fluorescence spectrometry. Soil Sci. Soc. Am. J. 77 (6), 2071–2077.

http://dx.doi.org/10.2136/sssaj2011.0174

http://dx.doi.org/10.1016/j.geoderma.2012.06.034


™™

• Farmers in Aztec, Farmington and Navajo nation who allowed access to fields for long

term monitoring of contaminations.

• EPA-NMED State Cooperative Agreement 01F22301

Assistance Program 66.204, Multipurpose Grants to Tribes and States.

• Advisors-Dr. April Ulery, Dr.Kevin Lombard, Dr.Colby Brungard

• B. Hunter, B. Francis, T. Charley, R. Ghorbani, E.Pointer, A. Matthews, H.Winsor,

J.Grijalva.

Acknowledgement


™™

Questions and feedback

all about discovery! new mexico state university situ ... · all about discovery! new mexico state...

Documents