Impact of sewage sludge spreading on heavy metal speciation in tropical soils (Réunion, Indian Ocean)

• Published in: Chemosphere (Oxford) Vol. 65; no. 2; pp. 286 - 293
• Main Authors: Dœlsch, Emmanuel, Deroche, Béatrice, Van de Kerchove, Virginie
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2006; Elsevier
• Subjects: agricultural soils; Agronomy. Soil science and plant productions; Applied sciences; Biological and medical sciences; chemical speciation; chromium; copper; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Monitoring; Exact sciences and technology; extraction; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; heavy metals; Indian Ocean; land application; Metals, Heavy - analysis; nickel; Other industrial wastes. Sewage sludge; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Pollution; Pollution, environment geology; Réunion; Sequential extraction; Sewage - analysis; Sewage - chemistry; Sewage sludge; Soil; soil organic matter; Soil Pollutants - analysis; soil pollution; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Speciation; Time Factors; Trace element; tropical soils; Wastes; X-Ray Diffraction; zinc; Reunion; Reunion island; Indian Ocean Islands; Indian Ocean; Indian Ocean, Mascarene Is., Reunion; ISW, Indian Ocean, Mascarene Is., Reunion; Mascarene Is., Reunion; Soil; Trace element; Sequential extraction; Réunion; Sewage sludge; Speciation; Cambisols; Pollutant behavior; Mobility; Agricultural soil; Soil pollution; Heavy metal; Tropical soil; Amendment; Volcanic soils; Upgrading; Risk assessment; Environment impact; Waste reuse; Agriculture; Water pollution; Ground water
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2006.02.046

This study was designed to evaluate the impact of sewage sludge spreading on tropical soilborne heavy metal speciation. Sludgeborne heavy metal speciation was also assessed, and the potential mobility of the elements was classified as follows: Zn > Ni ≫ Cu ≈ Cr. Two sequential extraction procedures were applied to study Cr, Cu, Ni and Zn speciation in control soils and sludge-amended soils. We demonstrated that sewage sludge spreading over a 2-year period did not have an impact on soilborne heavy metal concentrations but affected speciation of the most mobile fractions of Ni and Zn. Both protocols were consistent for the organic matter fractions, with an increase in Cu, Zn and Cr concentrations in the amended soil as compared to the control soil. In addition, we highlighted that the two protocols characterized different pools of organic matter and that organic compounds remained in the solid matrix after extraction. With respect to the reducible fraction, completely opposite results were obtained with the two protocols and the solid residue study revealed that the two schemes were ineffective in characterizing iron and manganese fractions.