Lead Speciation and In Vitro Bioaccessibility of Compost‐Amended Urban Garden Soils
| Autor: | M.D. Ransom, Ganga M. Hettiarachchi, Gary M. Pierzynski, Qing Ma, Chammi P. Attanayake |
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| Rok vydání: | 2017 |
| Předmět: |
Environmental Engineering
media_common.quotation_subject Amendment Biological Availability 010501 environmental sciences Management Monitoring Policy and Law engineering.material 01 natural sciences Soil Soil Pollutants Waste Management and Disposal 0105 earth and related environmental sciences Water Science and Technology media_common Compost Chemistry Composting Extraction (chemistry) 04 agricultural and veterinary sciences Pollution Bioavailability Soil conditioner Speciation Lead Environmental chemistry Soil water 040103 agronomy & agriculture engineering 0401 agriculture forestry and fisheries Gardens |
| Zdroj: | Journal of Environmental Quality. 46:1215-1224 |
| ISSN: | 1537-2537 0047-2425 |
| Popis: | In situ soil amendments can modify the Pb bioavailability by changing soil Pb speciation. Urban soils from three vegetable gardens containing different total Pb concentrations were used. The study evaluated how compost amendment and aging of soil-compost mixture in situ affected the following: (i) soil Pb speciation in the field and (ii) change of soil Pb speciation during an in vitro bioaccessibility extraction mimicking gastric phase dissolution at pH 2.5. X-ray absorption fine structure spectroscopy was used to determine Pb speciation in amended and nonamended soils and residues left after in vitro bioaccessibility extraction of those soils. Compost amendment and aging of compost in the field had a negligible effect on Pb bioaccessibility in the soils. Major Pb species in the soils were Pb sorbed to Fe oxy(hydr)oxide (Pb-Fh) and to soil organic C (Pb-Org). The fraction of Pb-Org was increased as soil-compost mixture aged in the field. During the in vitro extraction, the fraction of Pb-Fh was decreased, the fraction of Pb-Org was increased, and hydroxypyromorphite was formed in both amended and nonamended soils. Freshly incorporated compost enhanced the dissolution of Pb-Fh during the extraction. As soil-compost mixture aged in the field, the dissolution of Pb-Fh was low, demonstrating more stability of the Pb-Fh during the extraction. Compost amendment showed potential to contribute to reduced bioaccessibility of Pb as compost aged in the soil by increasing Pb-Org fraction in the field and stability of Pb-Fh during the in vitro bioaccessibility extraction. |
| Databáze: | OpenAIRE |
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