Ecotoxicity, phytotoxicity and extractability of heavy metals from different stabilised sewage sludges

• Published in: Environmental pollution (1987) Vol. 143; no. 2; pp. 355 - 360
• Main Authors: Fuentes, Ana, Lloréns, Mercedes, Sáez, José, Aguilar, M a Isabel, Pérez-Marín, Ana Belén, Ortuño, Juan F., Meseguer, Victor F.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-09-2006; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Applied sciences; Biological and medical sciences; Chemical Fractionation; DTPA-extractable metals; Ecosystem; Ecotoxicity assay; Environmental Pollutants - toxicity; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Heavy metals; Hordeum - growth & development; Hordeum vulgare; Lepidium - growth & development; Lepidium sativum; Metals, Heavy - toxicity; Other industrial wastes. Sewage sludge; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Pentetic Acid; Phytotoxicity assay; Plant Development; Plant Roots - growth & development; Pollution; Seeds - growth & development; Sewage; Sewage sludge; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Toxicity Tests; Waste Management; Wastes; Water Purification; Europe; Spain; Ecotoxicity assay; Phytotoxicity assay; DTPA-extractable metals; Sewage sludge; Heavy metals; Monocotyledones; Stabilization; Waste treatment; Cultivated soil; Lepidium sativum; Amendment; Cruciferae; Gramineae; Anaerobe; Upgrading; Dicotyledones; Risk assessment; Angiospermae; Agriculture; Biological treatment; Ecotoxicology; Hordeum vulgare; Pollutant behavior; Germination; Aerobe; Heavy metal; Phytotoxicity; Environment impact; Waste reuse; Spermatophyta
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2005.11.035

The presence of heavy metals in the sludges produced in wastewater treatment plants restricts their use for agricultural purposes. This study compares different types of sludges (aerobic, anaerobic, unstabilised and sludge from a waste stabilisation pond) in order to assess the extractability of heavy metals using simple extraction, water and DTPA. The stabilisation treatment undergone by the sludges influenced the heavy metals extractability. The least mineralised sludges (unstabilised and aerobic) showed higher metal extractability. The sewage sludges were subjected to chemical characterisation and toxicity testing (ecotoxicity and phytotoxicity assays) in absence of substrate, to provide a preliminary assessment of their suitability for land application. The ecotoxicity assays confirmed that no sludge constituted a hazardous waste. The sludge extracts had significant adverse effect on the germination index (GI) of barley (
Hordeum vulgare L.) and cress (
Lepidium sativum L.), a fact which indicates that some characteristics affected root growth.
Ecotoxicity and phytotoxicity assays provide a preliminary assessment of sludge suitability for land application.