Phosphorus (P) Lead (Pb) ~125 Years Remaining 2/19/2016

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Hortense Lee
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1 /9/06 Taking the Next Step: Exploration of Naturally Produced, Organic Compounds to Alter the Mobility and Lability of Soil Elements Joseph (Jay) Weeks Jr. and Ganga M. Hettiarachchi (Akafia et al. 0) Phosphorus (P) ~ Years Remaining Lead (Pb)

/9/06 EPA Residential Screening Limit: 00 mg kg ¹ http://projects.seattletimes.

org/wikipedia/commons/e/e9/brownfield_columbus.

as 0% (Shenoy and Kalagudi 00) What We Know Plants, fungi, bacteria, et cetera use a variety of carbon based

Lead: Remediation is expensive and difficult Efficacy is less than ideal in mildly contaminated soils I Have a

2 /9/06 EPA Residential Screening Limit: 00 mg kg ¹ The Issues Phosphorus: Poor plant availability regardless of total content Fertilizer use efficiency: As low as 0% (Shenoy and Kalagudi 00) What We Know Plants, fungi, bacteria, et cetera use a variety of carbon based compounds to acquire nutrients and alter the lability of contaminants. Lead: Remediation is expensive and difficult Efficacy is less than ideal in mildly contaminated soils I Have a Dream Compound The identity of the compound of interest cannot be divulged at this time Organic molecule that functions within an agriculturally relevant ph range Natural: produced in common living systems

/9/06 Objectives Investigate the ability of an organic compound to improve the plant availability of phosphate in soil.

bioavailability. Understand the mechanisms by which the above may be possible. Total Pb: ~990 mg kg ¹ (0.008 mol kg ¹) Total P: ~997 mg kg ¹ (0.0 mol kg ¹) Pb:P = :6.

jpg Column Investigation Passed mm sieve Ground then placed on roll mill overnight 0 g placed in plastic centrifuge tube Bulk density:.

cm³ Dried at 0 C overnight Lightly ground with pestle in a small plastic cup Analysis Mehlich-III Extractable P and Pb ICP-OES Total P and Pb Aqua regia digestion

3 /9/06 Objectives Investigate the ability of an organic compound to improve the plant availability of phosphate in soil. Our Starting Material Joplin, MO Smelter contaminated Excavated and landfilled Explore the use of an organic compound to immobilize lead thus decreasing bioavailability. Understand the mechanisms by which the above may be possible. Total Pb: ~990 mg kg ¹ (0.008 mol kg ¹) Total P: ~997 mg kg ¹ (0.0 mol kg ¹) Pb:P = :6.7 ph = ~6.7 Column Investigation Passed mm sieve Ground then placed on roll mill overnight 0 g placed in plastic centrifuge tube Bulk density:. g cm ³ Treatment to maximum water holding capacity: - water + buffer - + buffer Samples incubated at C for 7 hours Cut into sections Section -: cm³ Section : 7. cm³ Dried at 0 C overnight Lightly ground with pestle in a small plastic cup Analysis Mehlich-III Extractable P and Pb ICP-OES Total P and Pb Aqua regia digestion ICP-OES ph :0 (soil:water) Mechanistic Inquiry Amorphous Fe (Loeppert and Inskeep 996) Ammonium oxalate in the dark Sequential Extraction (Zhang and Kovar 009) Water or Mehlich-III minutes Exchangeable: M NH₄Cl 0. hour Al-P: 0.M NH₄F hour Fe-P: 0.M NaOH 7 hours Reductant soluble: Na-CBD 0. hour Ca-P: 0.M H₂SO₄ - hour Solution orthophosphate (Murphy and Riley 96)

/9/06 Phosphorus (mg/kg) 0 00 00 600 800 000 00 Percent

0 00 00 600 800 000 00 00 Percent "Available" Lead 0 6 8 0 -

4 /9/06 Phosphorus (mg/kg) Percent Available Phosphorus Total - M - Total - M Lead (mg/kg) Percent "Available" Lead Total - M - Total - M Native ph ph

5 /9/06 What s going on? Sequential Extraction - Phosphorus Alteration in iron mineralogy causing Pb and P release to solution may be chelating Pb and moving deeper in the soil profile prior to resorption Colloidal eluviation is not anticipated due to the failure of P to leach may be an effective treatment for native P mining and/or Pb immobilization in the future Many Unknowns Remain What fraction is being impacted? Speciation investigation next AS Is the P really plant available? Microbial contribution Are multiple applications possible? Can the application rate be increased? Will immobilization be a factor? Leaching concerns? Acknowledgements Advisor: Dr. Ganga Hettiarachchi K-State Agronomy Department K-State Soil Chemistry Group Caleb Gravesen and Oshadi Athukorala Arachchige Kansas State Research and Extension Vernon Schaffer and the Agronomy North Farm Thank You! %Fprotection-information%F&bvm=bv.0790,d.eY&psig=AFQjCNENsKZCAYnwrIBPiqrLsQhSQ0w&ust= der.com%fchart-of-the-day-arable-land-per-capita-0-&psig=afqjcnf6adowoauiseibhj8o7b0ekcg&ust=807 in.org%f%ftag%dlead-mining&psig=afqjcnhhlmokcs8wksnvjf_qc_ql-hq&ust=

The lack of soil phosphorus (P)

The lack of soil phosphorus (P) What About Fluid P Fertilizers In Moderately Calcareous Soils? Do they excel? Joy Pierzynski and Dr. Ganga Hettiarachchi The Fluid Journal Official Journal of the Fluid Fertilizer Foundation Winter 2016