Surface Application Of Biosolids Research Articles

Macronutrient and Trace Element Leaching Following Biosolids Application on Semi-arid Rangeland Soils

The objective of this study was to quantify the leachate concentration of macronutrients and trace elements obtained through intact soil columns containing two rangeland soils with different texture and amended with biosolids. This was done to evaluate the possibility that surface application of biosolids could adversely affect subsurface water quality via leaching. Biosolids were applied on the surface of the soil columns at 0 (control), 7, 18, 34, or 90 Mg ha−1 in dry basis. Results indicated that biosolids did not increase NO3 − − N leaching, except for the application of 90 Mg ha−1 in the Stellar soil (Calciargid), the finer-textured soil. In the Armesa soil (Haplocalcid), the coarser-textured soil, all leachate NO3 − − N concentrations were higher than the maximum contaminant limit (MCL) for drinking water established by USEPA, irrespective of biosolids treatment. Orthophosphate leaching occurred mostly in the Stellar soil and was favored by biosolids application. Of the trace elements that are regulated by USEPA, Cd, Ba, Cr, and Be were found below the MCL for drinking water irrespective of the biosolids application rate or soil type. The application of 90 Mg ha−1 of biosolids represented a significantly higher potential of leaching for many elements and compounds (NO3 − − N, SO4 =, Cl−, Ca, K, Mg, Na, and Sr) than applications of 34 Mg ha−1 or lower. In general, the application of biosolids up to 34 Mg ha−1 did not pose potential adverse effects for subsurface water quality.

Surface Biosolids Application: Effects on Infiltration, Erosion, and Soil Organic Carbon in Chihuahuan Desert Grasslands and Shrublands

Land application of biosolids is a beneficial-use practice whose ecological effects depend in part on hydrological effects. Biosolids were surface-applied to square 0.5-m2 plots at four rates (0, 7, 34, and 90 dry Mg ha(-1)) on each of three soil-cover combinations in Chihuahuan Desert grassland and shrubland. Infiltration and erosion were measured during two seasons for three biosolids post-application ages. Infiltration was measured during eight periods of a 30-min simulated rain. Biosolids application affected infiltration rate, cumulative infiltration, and erosion. Infiltration increased with increasing biosolids application rate. Application of biosolids at 90 dry Mg ha(-1) increased steady-state infiltration rate by 1.9 to 7.9 cm h(-1). Most of the measured differences in runoff among biosolids application rates were too large to be the result of interception losses and/or increased hydraulic gradient due to increased roughness. Soil erosion was reduced by the application of biosolids; however, the extent of reduction in erosion depended on the initial erodibility of the site. Typically, the greatest marginal reductions in erosion were achieved at the lower biosolids application rates (7 and 34 dry Mg ha(-1)); the difference in erosion between 34 and 90 dry Mg ha(-1) biosolids application rates was not significant. Surface application of biosolids has important hydrological consequences on runoff and soil erosion in desert grasslands that depend on the rate of biosolids applied, and the site and biosolids characteristics.

Using municipal biosolids in combination with other residuals to restore metal-contaminated mining areas

High metal waste materials from historic mining at the Bunker Hill, Idaho (ID) Superfund site was amended with a range of materials including municipal biosolids, woody debris, wood ash, pulp and paper sludge, and compost. The existing soil or waste material has elevated metal concentrations with total Zn, Pb and Cd ranging from 6000 to 14 700, 2100 to 27 000 and 9 to 28 mg kg −1 , respectively. Surface application of certain amendments including biosolids mixed with wood ash resulted in significant decreases in subsoil acidity as well as subsoil extractable metals. This mixture was sufficient to restore a plant cover to the contaminated areas. At the Bunker Hill site, a surface application of high N biosolids (44 or 66 tons ha −1 ) in combination with wood ash (220 tons ha −1 ) with or without log yard debris (20% by volume) or pulp and paper sludge (44 tons ha −1 ) was able to restore a vegetative cover to the metal contaminated materials for 2 years following amendment application. Plant biomass in 1999 was 0.01 mg ha −1 in the control versus a mean of 3.4 tons ha −1 in the residual amended plots. Metal concentrations of the vegetation indicated that plants were within normal concentrations for the 2 years that data were collected. Surface application of amendments was also able to reduce Ca(NO3)2 extractable Zn in the subsoil from about 50 mg kg −1 in the control to less than 4 mg kg −1 in two of the treatments. Use of conventional amendments including lime alone and microbial stimulants were not sufficient to support plant growth. These results indicate that surface application of biosolids in combination with other residuals is sufficient to restore a vegetative cover to high metal mine wastes.

Surface Application of Biosolids in the Chihuahuan Desert: Effects on Soil Physical Properties

Surface-applied biosolids can affect the physical properties of the topsoil and promote the rehabilitation of degraded soils. In this study, the effects of time after biosolids application (1-3, 6, 12, and 18 months) and biosolids application rate (0, 7, 18, 34, and 90 Mg ha-1) were assessed on selected physical soil properties, from shrubland (Ustic Calciargid) and grassland (Vertic Paleargid) soils. The bulk density (BD) of the 0- to 2.5-cm soil depth was significantly (P

Application of Biosolids to Degraded Semiarid Rangeland: Nine‐Year Responses

AbstractRangeland restoration through surface application of biosolids (municipal sewage sludge) is an increasing practice. Biosolids supply both organic matter and available nutrients that are lacking in degraded rangeland soils. This study investigated the effects of biosolids applications of 0, 22.5, 45, and 90 Mg ha−1 to a degraded rangeland in 1985 on the soil chemical properties and N mineralization potentials 8 and 9 yr after the application, respectively. Following an initial increase in proportion to the application rate, levels of water‐extractable Ca, Mg, Na, nitate (NO3‐N), and electrical conductivity declined to that near the control soils after 8 yr. Nearly all diethylenetriaminepentaacetic acid (DTPA)‐extractable metals (Fe, Zn, Cu, Cd, and Pb) were highest in the collection 4 yr after application, but were near concentrations in the control soil after 8 yr. Nitrogen mineralization potentials were significantly higher (P < 0.05) in the 45 and 90 Mg ha−1 applications after 9 yr, indicating that site fertility remained higher even though most soil chemical properties were returning to untreated levels.