title: Land application of aerobic sewage sludge does not impair methane oxidation rates of soils.
abstract: The aim of this study was to measure and compare methane oxidation rates of arable and grassland soils that received 7.5t ha⁻¹ y⁻¹ of noncontaminated aerobically treated sewage sludge for ten years. Arable soils showed generally lower methane oxidation rates (from 6 to 15∗10⁻³ h⁻¹) than grassland soils (from 26 to 33∗10³ h⁻¹). Oxidation rate constants (k) of soils amended with sewage sludge were remarkably close to their respective untreated controls, but a soil, that had received a tenfold sewage sludge application (i.e. 75 t ha⁻¹ y⁻¹), showed a statistically significantly higher k-value. Laboratory addition of up to 1000 mg Pb g⁻¹ soil to this soil did not cause any significant change in methane oxidation, but caused a decrease from 13.9 to 10.9×10⁻³ h⁻¹ in the control soil. Addition of Zn was much more toxic than Pb, with a significant decrease at 300 μg g⁻¹ soil rate and an almost complete inhibition at 1500 μg g⁻¹ soil rate. Higher resistance was evident of sewage sludge treated soil in comparison to control soil, for both biomass C and CH₄ oxidation activity.
authors.affiliation: Department of Agriculture and Environmental Sciences, University of Udine, Via delle Scienze 208, 33100 Udine, Italy. marco.contin@uniud.it
authors.forename: Marco
authors.initials: M
authors.lastname: Contin
authors.forename: Daniele
authors.initials: D
authors.lastname: Goi
authors.forename: Maria
authors.initials: M
authors.lastname: De Nobili
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000378:metabolism*; D018533:Biomass; D004784:Environmental Monitoring; D007558:Italy; D007854:Lead / Q000378:metabolism / Q000633:toxicity; D008697:Methane / Q000378:metabolism*; D010084:Oxidation-Reduction; D012722:Sewage; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity; D013997:Time Factors; D015032:Zinc / Q000378:metabolism / Q000633:toxicity
chemical_list: D012722:Sewage; D012989:Soil Pollutants; D007854:Lead; D015032:Zinc; D008697:Methane