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Potential availability of heavy metals to phytoextraction from contaminated soils induced by exogenous humic substances.
Chemosphere. 2003 Jul; 52(1):265-75.C

Abstract

Effective phytoremediation of soils contaminated by heavy metals depends on their availability to plant uptake that, in turn, may be influenced by either the existing soil humus or an exogenous humic matter. We amended an organic and a mineral soil with an exogenous humic acid (HA) in order to enhance the soil organic carbon (SOC) content by 1% and 2%. The treated soils were further enriched with heavy metals (Cu, Pb, Cd, Zn, Ni) to a concentration of 0, 10, 20, and 40 microg/g for each metal and allowed to age at room temperature for 1 and 2 months. After each period, they were extracted for readily soluble and exchangeable (2.5% acetic acid), plant-available (DTPA, Diethylentriaminepentaacetic acid), and occluded (1 N HNO(3)) metal species. Addition of HA generally reduced the extractability of the soluble and exchangeable forms of metals. This effect was directly related to the amount of added HA and increased with ageing time. Conversely, the potentially plant-available metals extracted with DTPA were generally larger with increasing additions of exogenous HA solutions. This was attributed to the formation of metal-humic complexes, which ensured a temporary bioavailability of metals and prevented their rapid transformation into insoluble species. Extractions with 1 N HNO(3) further indicated that the added metals were present in complexes with HA. The observed effects appeared to also depend on the amount of native SOC and its structural changes with ageing. The results suggest that soil amendments with exogenous humic matter may accelerate the phytoremediation of heavy metals from contaminated soil, while concomitantly prevent their environmental mobility.

Authors+Show Affiliations

Halim M
Départment de Chimie, Université Mohamed V, Rabat, Morocco.
Conte P
No affiliation info available
Piccolo A
No affiliation info available

MeSH

Biodegradation, EnvironmentalBiological AvailabilityHumic SubstancesMetals, HeavyPlantsSoil PollutantsTemperatureTissue Distribution

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

12729711

Citation

Halim, M, et al. "Potential Availability of Heavy Metals to Phytoextraction From Contaminated Soils Induced By Exogenous Humic Substances." Chemosphere, vol. 52, no. 1, 2003, pp. 265-75.
Halim M, Conte P, Piccolo A. Potential availability of heavy metals to phytoextraction from contaminated soils induced by exogenous humic substances. Chemosphere. 2003;52(1):265-75.
Halim, M., Conte, P., & Piccolo, A. (2003). Potential availability of heavy metals to phytoextraction from contaminated soils induced by exogenous humic substances. Chemosphere, 52(1), 265-75.
Halim M, Conte P, Piccolo A. Potential Availability of Heavy Metals to Phytoextraction From Contaminated Soils Induced By Exogenous Humic Substances. Chemosphere. 2003;52(1):265-75. PubMed PMID: 12729711.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Potential availability of heavy metals to phytoextraction from contaminated soils induced by exogenous humic substances. AU - Halim,M, AU - Conte,P, AU - Piccolo,A, PY - 2003/5/6/pubmed PY - 2003/6/25/medline PY - 2003/5/6/entrez SP - 265 EP - 75 JF - Chemosphere JO - Chemosphere VL - 52 IS - 1 N2 - Effective phytoremediation of soils contaminated by heavy metals depends on their availability to plant uptake that, in turn, may be influenced by either the existing soil humus or an exogenous humic matter. We amended an organic and a mineral soil with an exogenous humic acid (HA) in order to enhance the soil organic carbon (SOC) content by 1% and 2%. The treated soils were further enriched with heavy metals (Cu, Pb, Cd, Zn, Ni) to a concentration of 0, 10, 20, and 40 microg/g for each metal and allowed to age at room temperature for 1 and 2 months. After each period, they were extracted for readily soluble and exchangeable (2.5% acetic acid), plant-available (DTPA, Diethylentriaminepentaacetic acid), and occluded (1 N HNO(3)) metal species. Addition of HA generally reduced the extractability of the soluble and exchangeable forms of metals. This effect was directly related to the amount of added HA and increased with ageing time. Conversely, the potentially plant-available metals extracted with DTPA were generally larger with increasing additions of exogenous HA solutions. This was attributed to the formation of metal-humic complexes, which ensured a temporary bioavailability of metals and prevented their rapid transformation into insoluble species. Extractions with 1 N HNO(3) further indicated that the added metals were present in complexes with HA. The observed effects appeared to also depend on the amount of native SOC and its structural changes with ageing. The results suggest that soil amendments with exogenous humic matter may accelerate the phytoremediation of heavy metals from contaminated soil, while concomitantly prevent their environmental mobility. SN - 0045-6535 UR - https://www.unboundmedicine.com/medline/citation/12729711/Potential_availability_of_heavy_metals_to_phytoextraction_from_contaminated_soils_induced_by_exogenous_humic_substances_ DB - PRIME DP - Unbound Medicine ER -