Showing papers in "Journal of Environmental Quality in 1990"

Application of Radioactive Fallout Cesium-137 for Measuring Soil Erosion and Sediment Accumulation Rates and Patterns: A Review

Abstract: Radioactive fallout Cs (cesium-137) deposited across the landscape from atmospheric nuclear tests is strongly absorbed on soil particles limiting its movement by chemical and biological processes Most Cs movement in the environment is by physical processes; therefore, Cs is a unique tracer for studying erosion and sedimentation Cesium-137 loss from a watershed has been shown to correlate strongly with soil loss calculated by the Universal Soil Loss Equation (USLE) or measured from small runoff plates By measuring spatial patterns of Cs in vertical and horizontal planes across the landscape, rates of soil loss or deposition can be measured for different parts of a watershed Even within landscape units, redistribution of soil can be mapped and erosion or deposition rates for different parts of individual fields measured and mapped Sediment accumulation rates can be measured by comparing the vertical distribution of Cs in sediments with the temporal deposition of fallout Cs from the atmosphere to locate sediment horizons Using these dated sediment horizons, sediment accumulation rates can be measured Interpretations about the location of these dated horizons must consider particle size of the sediments, reworking of deposited sediments, diffusional movement of Cs, and time rates of physical process in the sedimentation process The Cs technique can be used to determine sediment accumulation rates in a wide variety of depositional environments including reservoirs, lakes, wetlands, coastal areas, and floodplains The bibliography shows that Cs has been used widely for studying erosion and sedimentation in many different environments around the world

Nitrous oxide emissions from fertilized soils: summary of available data.

Abstract: Direct measurements of fertilizer-derived N₂O emission data from 104 field experiments reported in agriculture and soil science literature that were obtained between 1979 and 1987 were summarized and used to estimate worldwide fertilizer-derived N₂O emissions. Although without statistical determination, there appears to be a trend between emissions and type and quantity of fertilizer applied; the available data does not indicate a trend between emissions and a particular soil type or agriculture system. Using the fraction of the N fertilizer evolved as N₂O and fertilizer consumption estimates for five fertilizer types, 0.1 to 1.0 Tg N₂O-N (avg. 0.3; median 0.2) were estimated to be released during the “sampling period.” If these estimates are doubled to account for emissions after the sampling period and emissions from fertilizer lost in drainage water and ground-water, the expected range would be 0.2 to 2.1 Tg N₂O-N (avg. 0.7; median 0.5) emitted into the atmosphere in 1984. The magnitude of this estimate is in agreement with recent global estimates. If 100 Tg N fertilizer are consumed worldwide in the year 2000, the global release of fertilizer-derived emissions into the atmosphere will probably not exceed 3 Tg N₂O-N in the year 2000. It is estimated that 23 to 315 Gg N₂O-N were emitted into the atmosphere from fields of cultivated leguminous crops in 1986. Future research needs were suggested. This paper does not necessarily reflect the official position of the USEPA.

An ultraviolet absorbance method of estimating the percent aromatic carbon content of humic acids.

Abstract: (...) A rapid method of estimating the aromatic C content of humic acids would be useful in studies of the fate of nonpolar organic solutes in soils and natural waters. The relationship between the UV absorptivity of nine different dissolved humic substances, measured at a wavelength of 272 nm, and their aromatic C content, as determined by 13 C CPMAS NMR, was evaluated. (...)

Plant Responses to Rising Carbon Dioxide and Potential Interactions with Air Pollutants

Abstract: As global population increases and industrialization expands, carbon dioxide (CO 2 ) and toxic air pollutants can be expected to be injected into the atmosphere at increasing rates. This analysis reviews a wide range of direct plant responses to rising CO 2 , increasing levels of gaseous pollutants, and climate change, and to potential interactions among the factors. Altough several environmental interactions on stomata and foliage temperatures are reviewed briefly, a comprehensive review of effects of potential climatic change on plants is not a major objective of this analysis

Geochemical factors controlling the mobilization of inorganic constituents from fossil fuel combustion residues: II. Review of the minor elements.

Abstract: Past studies of the environmental aspects of fossil fuel waste disposal have focused on determining elemental concentrations, elemental distributions, and empirical rates of elemental extraction. The concentration data for the minor elements (i.e., As, B, Ba, Cd, Cr, Cu, Pb, Mn, Hg, Mo, Ni, Se, Sr, V, and Zn) are extremely variable and are dependent on fuel composition and combustion processes. Studies of elemental extraction rates have provided empirical information on short-term leaching behavior that is relevant only to a specific waste sample. Extraction studies serve to characterize the initial states of wastes prior to disposal but generally have not provided information on the dominant weathering reactions that will control the long-term concentrations of minor elements in the disposal environment. We propose that a more useful approach for understanding leachate chemistry involves the consideration of the thermodynamics of specific dissolution/precipitation, adsorption/desorption, and redox speciation reactions that occur during weathering in addition to empirical data. Because fossil fuel wastes are composed of high-temperature solids that formed under conditions of combustion, this approach can be used to describe the reaction paths governing the alteration of the high-temperature solids to assemblages of secondary solids and aqueous species that are stable in weathering environments. The depiction of leaching behavior through solubility and speciation relationships rather than through empirical interpretations of extraction rates allows one to establish bounds for the aqueous concentrations of various elements, given information on the chemistry of waste solids and on physical and chemical conditions. The determination of thermodynamic data and application of those data to understanding the leachate chemistry of the minor elements in the disposal environment remains an area where much research is needed. Research supported by the Electric Power Res. Inst., Palo Alto, CA, under contract 2485-8.

The fate of nitrogenous fertilizers applied to turfgrass

Abstract: The purpose of this paper is to provide a review and critical analysis of the current state of knowledge of the effect of nitrogenous fertilizers applied to turfgrass on groundwater quality. This review can be useful in providing information on the development of best management practices to minimize the impact of turfgrass fertilization on groundwater quality and to indicate gaps in the knowledge base, which can emphasize future research needs

Geochemical factors controlling the mobilization of inorganic constituents from fossil fuel combustion residues

Abstract: Etude du lessivage dans le sol lors de l'epandage de dechets de combustibles fossiles: cendres volantes, particules en suspension et boues de desulfuration d'effluents gazeux

Constructed Wetlands for Wastewater Treatment: Municipal, Industrial, and Agricultural

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A Review of the Response of Epicuticular Wax of Conifer Needles to Air Pollution

Abstract: The effects of air pollutants on the epicuticular wax structure of conifer needles and the ecophysiological consequences of the injuries are reviewed on the basis of published literature and the authors' recent investigations. Degradation of the epicuticular waxes, which appears as a fusion of wax tubes in the epistomatal chambers and finally results in an amorphous appearance of the waxes, is the most common micromorphological injury type observed in studies on the genera Abies, Larix, Picea, and Pinus. The rate of erosion correlates well with the level of air pollution, but clear evidence for the specificity of the symptoms for different air pollutants has not been observed. It is concluded that the erosion of the epicuticular waxes, a phenomenon with a large geographic distribution, is a relevant factor of the multiple forest decline syndrome. Erosion of the waxes can change needle wettability and rain retention. Increased needle wettability and permeability of the cuticles can result in enhanced leaching of nutrients and uptake of pollutants. Increased or decreased stomatal and cuticular diffusion resistance of the needles leads to altered transpiration rates. Due to the changed chemical microenvironment of the needles, the conifers are predisposed to various biotic and abiotic stresses. Because the epicuticular waxes are one of the first targets of a variety of air pollutants, they can widely be used as an early indicator of air pollution effects. This work was supported by the Academy of Finland. Contribution from the Dep. of Botany, Univ. of Oulu.

Adsorption and Desorption of 2,4,6-Trinitrotoluene by Soils

Abstract: : Soil samples collected from 12 Army Ammunition Plants were characterized by chemical and physical tests. Tests included pH, particle size distribution, cation exchange capacity, electrical conductivity, percent organic carbon, and extractable iron, manganese, aluminum, and calcium. Soils were found to be primarily silty loams, low in organic carbon. Trinitrotoluene (TNT) reached a steady state of adsorption with test soils (i.e., no change in TNT solution concentration) within 2 hr of contact. Desorption kinetics indicated that desorption was also rapid. A steady state of desorption occurred within 2 hr with more than half of the adsorbed TNT being removed. Batch adsorption isotherms were linear with an average adsorption coefficient (soil concentration/solution concentration, or Kd of 4.0. However, Kd varied with soil type. The TNT adsorption correlated most highly with cation exchange capacity, extractable iron, clay content, and present organic carbon. Sequential desorption indicated that almost all of the adsorbed TNT was desorbed after three desorption cycles. Therefore, soil sorption of TNT will not effectively prevent mobility of TNT in the environment unless more strongly adsorbed degradation products are formed.

Effect of conventional vs. No-tillage on pesticide leaching to shallow groundwater

Abstract: Atrazine was found in groundwater all year, while cyanazine, alachlor, and carbofuran were present only for a short period (<3 mo) after pesticide application. Fairly constant background levels of <0.5 μg L −1 atrazine were found under fields treated before 1986, while levels under continuously treated fields were <2.0 μg L− 1 for 22 of 25 samplings. Pesticide residues in unconfined groundwater were usually higher (ca. 2 to 4×) than in confined groundwater. Rainfall timing relative to pesticide application was critically important to pesticide leaching

Soil nitrate accumulations following nitrogen-fertilized corn in Pennsylvania

Abstract: Devenir des nitrates issus de la fertilisation des cultures de mais (Zea mays) dans le sol et les eaux souterraines

Influence of Fly Ash on Soil Microbial Activity and Populations

Abstract: Incubation studies were conducted to assess the influence of various combination levels of alkaline (pH 12.2) powerplant fly ash and sewage sludge on soil microbial activity and numbers. A Glynwood (fine, illitic, mesic. Aquic Hapludalf) silt loam soil was mixed with 0, 5, 10, or 20% (w/w) ash and 0 or 5% composted sewage sludge. Respiration was strongly depressed in the 10 and 20% ash treatments over 28 d. Sludge addition improved respiration in all ash treatments except the 20% treatment. Total bacterial, actinomycete, and fungal counts in the soil typically decreased with increasing ash content. Counts were depressed by 57, 80, and 86%, respectively, at the 20% ash application rate. Sludge application increased microbial numbers but all populations were lower at the highest ash rates compared to the untreated control. Soil phosphatase, sulfatase, dehydrogenase, and invertase were inhibited as ash treatment levels increased. Catalase activity was not significantly affected by ash concentration. Addition of the sludge to the ash-soil mixtures generally enhanced enzyme activity. The results indicate that high rates of fly ash to soils may hinder normal decomposition and nutrient cycling processes. This may be partially alleviated, however, by coapplication of a readily oxidizable organic substrate such as sewage sludge.

Content and fractionation of heavy metals in water treatment sludges.

Abstract: Mesure des teneurs en cadmium, cuivre, chrome, nickel, plomb et zinc dans les boues residuaires de traitement d'eau potable par coagulation

Virus transport and survival in saturated and unsaturated flow through soil columns

Abstract: Etude comparative au moyen de colonnes de sol des effets de l'ecoulement sature et non sature sur la survie et le transport d'un virus, bacteriophage MS-2

Oxygen Transport through Aquatic Macrophytes: The Role in Wastewater Treatment

Abstract: Laboratory experiments were conducted to determine the effectiveness of three floating and six emergent aquatic macrophytes in improving domestic wastewater quality, based on their capacities for O₂ transport into the effluent Oxygen transport into the rooting zone of the plants created an oxidized microenvironment, thereby stimulating C and N transformations critical to wastewater treatment Plants were cultured in flasks containing deoxygenated primary and secondary sewage effluent for an 8-d period Oxygen transport by the plants was measured in terms of both O₂ consumed by the effluent (biological O₂ demand reduction—BOD₅) and increased effluent dissolved O₂ Two floating plants, pennywort (Hydrocotyle umbellata L) and waterhyacinth [Eichhornia crassipes (Mart) Solms], and the emergent plants pickerelweed (Pontederia cordata L) and common arrowhead (Sagittaria latifolia L), were superior in improving primary sewage effluent quality, by reducing BOD₅ up to 88%, NH₄-N up to 77%, and increasing dissolved O₂ up to 61 mg L⁻¹ Nitrification rates in pennywort- and water hyacinth-based water treatment systems were calculated to be in the range of 12 to 47 kg NH₄-N ha⁻¹ d⁻¹ Oxygen transport through plants accounted for up to 90% of the total O₂ transported into the effluent In separate batch experiments, the effectiveness of diffuse mechanical aeration (5 and 50 mL air min⁻¹) and of biological aeration (O₂ transport by selected plants including pennywort, waterhyacinth, pickerelweed, and common arrowhead) on the rate of contaminant removal from deoxygenated primary sewage effluent were compared for a 26-d period Biological and mechanical aeration effected similar BOD₅ removal First-order reaction rate constants for BOD₅ removal were from 00066 to 00079 h⁻¹ and from 00041 to 00051 h⁻¹ for biological and mechanical aeration, respectively Rate constants for NH₄-N removal were from 00024 to 00107 h⁻¹ for the plant treatments Virtually complete BOD₅ removal occurred in biological and mechanical aeration treatments within 20 d Complete nitrification of NH₄-N had occurred within 12 d after mechanical aeration was initiated, but subsequent N-loss by denitrification was inhibited In the biological aeration treatments, negligible effluent (NO₃ + NO₂)-N levels were measured, but 65 to 100% NH₄-N loss occurred both by plant assimilation and by sequential nitrification-denitrification reactions Florida Agric Exp Stn Journal Series R-00084

Nitrate contamination of groundwater under irrigated Coastal Plain soils.

Abstract: Determination des profils verticaux et saisonniers du lessivage des nitrates au-dessus de sols irrigues. Comparaison du lessivage de sols traites par du fumier de volaille et des engrais commerciaux, des profils de concentration en nitrate dans l'eau souterraine et les sols

Nitrate leaching from systematically tiled potato fields in New Brunswick, Canada.

Abstract: Drain outflow volumes averaged 75 and 115 nm per unit area in 1987 and 1988, respectively. Considerable drain flow occurred during snowmelt each year before data collection began. Measured NO 3 -N concentrations ranged from 1 to 65 mg L −1 and there were substantial changes in NO 3 -N concentrations within flow events. The flow-weighted average annual nitrate concentrations of the drainage effluent, (NO 3 -N) a f , were ≥10 mg L −1 for potato site-years, regardless of whether the sites were established potato rotation fields or not

Aerobic and Anaerobic Degradation of Alachlor in Samples from a Surface‐to‐Groundwater Profile

Abstract: Estimates of pesticide degradation rates in subsoils are needed to improve models predicting pesticide movement to groundwater. Biodegradation rates of the herbicide alachlor [2-chloro-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] in surface soil, vadose zone, and aquifer samples collected from a single site near Plains, GA were determined in the laboratory under aerobic and anaerobic conditions. Degradation was described by first-order kinetics during 126 d of incubation. Under aerobic conditions the halflife (t₁/₂) of alachlor in the surface soil (t₁/₂ = 23 d) was less than in the vadose zone (t₁/₂ = 73 to 285 d) and aquifer samples (t₁/₂ = 320 to 324 d). Alachlor in anaerobic samples degraded less rapidly in the surface (0 to 0.6 m) and the next deepest (0.6 to 2.4 m) subsoil than under aerobic conditions (t₁/₂ = 100 and 144 d, respectively). Degradation in anaerobic aquifer samples was very slow (t₁/₂ = 337 to 553 d). Addition of organic nutrients enhanced aerobic degradation in subsurface soils and one aquifer sample, indicating that nutrient availability limits biodegradation. Total aerobic microbial populations ranged from 6.6 × 10³ to 2.5 × 10⁶ cells per gram of soil in the subsoils and aquifer samples, but were not correlated with aerobic or anaerobic degradation rates. The lower degradation rates in vadose zone and aquifer materials may be due to less microbial activity or the absence of alachlor degraders.

Nutrient cycling in forests of Walker Branch Watershed, Tennessee : roles of uptake and leaching in causing soil changes

Abstract: Previous studies showed that subsoil exchangeable Ca 2+ and Mg 2+ decreased over the period 1971 to 1982 in several plots on Walker Branch Watershed. It was hypothesized that wood accumulation (i.e., uptake and sequestering in both living and dead tree biomass) was the dominant cause of the exchangeable Ca 2+ decreases, whereas atmospheric deposition-induced leaching was the dominant cause of the exchangeable Mg 2+ decreases

Sensitivity of Tree Seedlings to Aluminum: III. Red Spruce and Loblolly Pine

Abstract: (...) Results of experiments with seedlings grown in solution, sand, and soil indicate minimal involvement of Al in the decline of loblolly pine. However, both controlled studies and field data indicate that reductions in tissue Ca and Mg may occur at Al concentrations well below those causing direct injury. Thus, Al may be involved in reductions in pine growth through interference with nutrient uptake and translocation. (...)

Tracked vehicle impacts on vegetation at the Pinon Canyon Maneuver Site, Colorado.

Abstract: (...) Changes in cover in untracked areas was attributed to above average precipitation and the cessation of domestic livestock grazing. Overall (tracked plus untracked areas), total cover increased on PCMS, but the proportion of annual cover also increased. Woody plant density decreased an average of 9% from 1985 to 1987. Long-term management of the soil and vegetative resources of PCMS are discussed