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Dry Flue Gas Desulfurization Byproducts as Amendments for Acid Agricultural Soils
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Dry flue gas desulfurization (FGD) byproducts result from the removal of SO2 from the stack gases of coal-fired boilers and are mixtures of coal fly-ash, CaS04 and unspent sorbent. Dry FGD byproducts frequently have neutralizing values greater than 50% CaC03 equivalency and thus have potential for neutralizing acid agricultural soils. Owing to the presence of soluble salts and various trace elements, however, soil application of dry FGD byproducts may have adverse effects on plant growth and soil and water quality. The use of a dry FGD by-product as a limestone substitute was investigated in a field study on three acid agricultural soils (pH 4.6,4.8, and 5.8) in eastern Ohio. The by-product (60% CaC03 equivalency) was applied in September, 1992, at rates of 0,0.5, 1.0, and 2.0 times the lime requirement of the soils, and alfalfa (Medicago sativa L.) and corn (Zea mays L.) were planted. Soils were sampled in April, 1993 and analyzed for pH and water soluble concentrations of 28 elements. Soil pH was increased by all FGD rates in the zone of incorporation (0-10 an), with the highest rates giving a pH slightly above 7. At 10- to 20-cm, pH was increased from 4.7 to 5.2 in two soils; there was no effect on pH at 20- to 30-cm. Calcium, Mg, and S increased, and Al, Mn, and Fe decreased with increasing dry FGD application rates. No trace element concentrations were changed by dry FGD application except B which was increased in the zone of incorporation. Dry FGD increased alfalfa yield on the most acidic soil, and decreased corn grain yield on another soil. Application of dry FGD equivalent to the lime requirement of acid soils appears to be beneficial to acid-sensitive crops such as alfalfa. No detrimental effects on soil quality were observed in this study.
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... The amount of B added with the by-products was low except for the FBC and FGD+lime treatments, and most of the B added with these by-products leached from the columns (Table 2). However, increases in soil exchangeable B have been reported when B-containing CCBs were applied to soil (Stehouwer et al., 1994). ...
Application of coal combustion by-products (CCBs) to acid soils can have beneficial or detrimental effects. A column study was conducted to determine the effects of CCBs on mitigating acid soil properties after leaching with 138 cm deionized water. Columns containing 105 cm acidic Lily soil (Typic Hapludult) had mixed in the top 15 cm the following treatments (g/kg soil): no CCB or limestone (check); dolomitic limestone (lime) at 3.98; high-calcium sulfate (CaSO4) flue gas desulfurization (FGD) by-product (BP) at 15.88; combination of lime+FGD at rates given; high-CaSO4 FGD BP enriched with Mg (FGD+Mg) at 15.88; and fluidized bed combustion (FBC) BP at 6.45. After being leached for 39 days, the columns of acid soil treated with high-CaSO4 by-products showed higher subsurface pH, calcium (Ca), and sulfur (S) and lower aluminum (Al) and manganese (Mn). In contrast, the lime alone treatment had little effect on subsurface soil properties. Use of dolomitic limestone to supply magnesium (Mg) in conjunction with the CaSO4 treatments was more effective than supplementation with Mg(OH)2, where 97% of the added Mg leached from the top layer. Substances leached from the CCBs studied were effective in reducing problems associated with subsurface soil acidity.
... Leaching and/or weathering to reduce B content in FBCBAs that may induce plant toxicity have been recommended when fly ash is applied to soil (Sharma et al., 1988; Townsend and Gilliam, 1975). Boron levels were relatively high in the soil incorporation zone when mixtures of FBCBA and fly ash were added simultaneously to reduce soil acidity (Stehouwer et al., 1994). Maize grown on acid soil amended with FBCBA at 10 g kg" 1 in unleached containers (greenhouse) had reduced DM (Clark et al., 1995), and B levels in leaf tissue were sufficiently high to implicate B toxicity (R.B. ...
Fluidized bed combustion bottom ash (FBCBA) from coal burning power plants often contain substances that detrimentally affect plant growth [(e.g., boron (B)] when applied to soil. Leaf symptoms similar to B toxicity appeared when maize (Zea mays L.) was grown during Year-1 of a field experiment where FBCBA was incorporated (6,790 and 13,580 kg ha-1) in an acidic soil (Aquic Hapludult). Soil extractable B increased with increased levels of FBCBA in Year-1 and in Year-2. Although levels in Year-2 were lower than in Year-1 they were still sufficiently high to raise concern about B toxicity. Acquisition of B in leaves of maize grown in Year-1 was relatively high at the 5-leaf stage of growth, and at a normal level in the ear leaf; ear leaf B in Year-1 was greater than ear leaf B in Year-2. Grain and fodder yields of plants grown with added FBCBA were reduced in Year-1, but not in Year-2. A greenhouse study was conducted to determine leachability of B through acidic soil (Typic Hapludult) columns whose surface had been treated with FBCBA at 0, 6, and 12 g kg-1 soil and leached with different amounts of water (25, 200, and 800 mm). Maize was also grown on the leached soil columns to determine effects of compounds leached from FBCBA on growth and B acquisition in leaves. The application of 800 mm of water reduced soil levels B, and increased the amount of B leached from the columns. Maize shoot and root dry matter (DM) were enhanced with FBCBA. Increased DM associated with higher FBCBA levels may reflect increased soil pH in this acidic soil. Shoot B concentrations decreased with greater amounts of water used to leach columns. Shoot B concentrations were closely related to levels of B present in the 0-15 cm layer of soil in the column and field experiments.
Mining and drilling are two methods used for extracting underground fossil fuels. While mining extracts solid fossil fuels and other economically important buried solid resources by way of digging and scraping, drilling extracts liquid (e.g., conventional oil) or gaseous (e.g., natural gas) fossil fuels that are forced to flow to the earth surface. Both processes are equally hazardous and cause serious health and environmental impacts like landscape degradation, vegetation and biodiversity loss, habitat fragmentation, and generation of acid mine drainage (AMD). AMD is formed when water draining through deep mines, surface mines, and mine waste materials come in direct contact with the pyrite (iron sulfide) containing exposed rocks, causing sulfuric acid production that further dissolves other rocks, and heavy metals present in them polluting waterways and groundwater with acid, dissolve ions and heavy metals. The threats of AMD pollution continue even long after the closure of the mine and abandoned mining sites are difficult to restore without treatment due to this acidic AMD effect. Unlike mining and drilling that cause direct damage to natural ecosystems, burning coal for thermal energy produces a huge quantity of coal combustion products (CCPs), disposal of which poses another challenge. Five major types of CCPs (bottom ash; boiler slag; fly ash; fluidized bed combustion ash or FBC; flue gas desulfurization ash or FGD) are used in mine reclamation either in a single form or in various combinations. Among the different utilizations of CCPs, mine reclamation is one of the most important beneficiations as the lime content of CCPs can easily neutralize acidic water and prevent or minimize AMD. While the placement of fly ashinto deep mines give structural support to abate subsidence, placement of fly ash into surface mines or other open pits or mine overburdens help in fights against AMD as the strong packing and absorbing nature of the fly ash reduces the permeability of mine strata and divert away water from acid-generating materials. The final step of reclamation is covering the fly ash treated underground and surface mining lands with the plantations that aid in the containments of the pollutants or phytostabilize them and accelerate phytorestoration of the pre-mining habitat. Therefore, scientifically sound rehabilitation of the mines through proper phytomanagement with native plants should be designed to produce a sustainable fuelwood or bioenergy crop plantation and contribute to the prevention of climate change through encouraging clean green energy.
With the continued use of coal to generate electricity for the world's power needs, coal combustion by-products (CCPs) will be produced in greater quantities during the ensuing decades. About 130 million tons of CCPs are produced annually from the 600 coal-fired power plants currently operating in the USA, with estimates of 500 million tons produced worldwide. Five major types of CCPs exist: bottom ash; boiler slag; fly ash; fluidized bed ash; flue gas desulfurization ash. Bottom ash does not generally constitute a disposal problem because it is extensively used as aggregate fill material for construction projects, filler in construction materials (wall board and dry wall) and de-icing solids for roads. Boiler slag is used for similar purposes as bottom ash, but it can be used as a glassy grit material for sand blasting. Fly ashes constitute 70% of the by-products generated and these ashes are produced in several ways in a power plant depending on the boiler type and the emission control system employed at the power plant. These fine-textured ash materials may be dry fly ash from conventional coal-fired boilers, dry ashes collected in flue-gas desulfurization or other collection devices (bag houses or scrubber filters), or they may be collected in wet scrubber systems producing a fly ash slurry.
In the present paper, the potential use of lignite fly ash in the control of acid generation from sulphidic tailings disposed of at Lavrion, Greece was studied. Long-term laboratory column kinetic tests were performed on tailings containing 27% S, which were homogeneously mixed with various amounts of fly ash, ranging from 10 to 63% w/w. The drainage quality of the columns was monitored over a test period of 600 days. Chemical and mineralogical characterisation of column solid residues was performed after a 270-day test period. The hydraulic conductivity of the mixtures was also measured to evaluate the potential of fly ash to form a low permeability layer. Based on the results, the addition of fly ash to sulphidic tailings, even at the lower amount, increased the pH of the drainage at values of 8.6-10.0 and decreased the dissolved concentrations of contaminants, mainly Zn and Mn, to values that meet the European regulatory limits for potable water. Higher fly ash addition to tailings, at amounts of 31 and 63% w/w also reduced the water permeability of material from 1.2 x 10(-5) cm/sec to 3 x 10(-7) and 2.5 x 10(-8) m/s, respectively.
Previous version: Mylavarapu, Rao, and Elizabeth Kennelley. 1. “UF/IFAS Extension Soil Testing Laboratory (ESTL) Analytical Procedures and Training Manual”. EDIS 2002 (5). https://doi.org/10.32473/edis-ss312-2002.
During the winters of 1974-1975 and 1975-1976 food habits of the Entiat mule deer (Odocoileus hemionus hemionus) herd were quantified in sites with high, medium and low antelope bitterbrush (Purshia tridentata) abundance. Using a microscopic technique, 27 plant species were identified in fecal samples. Bitterbrush, buckwheat (Eriogonum spp.), arrowleaf balsamroot (Balsamorhiza sagittata) and lupine (Lupinus spp.) combined made up 87%-93% of the diet in the three sites. Bitterbrush use was heavy in sites where it was available; however, as its availability declined, buckwheat replaced it in the herd's diet. In the site with a low bitterbrush abundance lupine also replaced bitterbrush in the herd's diet. Balsamroot use remained relatively constant in all sites during both winters. Changes in bitterbrush abundance significantly affected the diet of the mule deer herd; however, these changes were not thought to adversely affect the winter survival of the deer herd.
A method of plot sampling for canopy volume of shrubs in plant communities is described. The method requires a three dimensional plot and an estimation of canopy volume by classes for each species in the plot. Midpoint values for the volume classes are used to calculate averages from an appropriate sample size. The method eliminates the necessity of measuring height and canopy diameters of individual species and provides an acceptable index to species dominace in the vegetation.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations.
Differences in aboveground tissue concentrations of trace elements were assessed for sweetgum (Liquidambar styraciflua L.) and sycamore (Plantanus occidentalis L.) growing on two abandoned coal fly ash basins and a control soil. The wet basin (pH = 5.58) had originally received precipitator ash in an ash-water slurry, while the dry basin (pH = 8.26) had received both precipitator and bottom ash in dry form. In general, trees from the wet basin exhibited elevated trace element concentrations in comparison to the controls, while the dry basin trees exhibited reduced concentrations. On eof the most striking differenced in elemental concentrations among the ash basin and control trees was observed for Mn, with the control trees exhibiting concentrations orders of magnitude greater than the ash basin trees. Differences in foliar trace element concentrations among the sites can generally be explained by differences in substrate trace element concentrations and/or substrate pH. While trees from the wet ash basin generally had the highest trace element concentrations, these trees also attained the greatest height and diameter growth, suggesting that the elevated trace element concentrations in the wet basin substrate are not limiting the establishment of these two species. The greater height and diameter growth of the wet basin trees is presumably a result of the greater water-holding capacity of the substrate on this site. Differences in growth and tissue concentrations between sweetgum and sycamore highlight the importance of using more than one species when assessing metal toxicity or deficiency on a given substrate.
Uptake of trace elements in annual ryegrass (L. multiflorum Lam.) grown in mixtures of three gasification ashes and two soils under greenhouse conditions is reported. The gasification ashes selected were those produced in fluidized-, fixed-, and entrained-bed gasification processes. Soils consisted of a surface agricultural soil and a subsurface weathered shale. Plant uptake was evaluated under two management regimes, with and without lime and fertilizer amendments. Six harvests were made over 180 d. Ryegrass yields were highly dependent on application of lime and fertilizer regardless of quantity or type of ash in the soil-ash mixtures. Yields from unlimed/unfertilized treatments were low because of the limited supply of N, P, and K and phytotoxic levels of Al, Cd, Ni, and Zn. The entrained-bed ash contained a relative high S concentration (38 g/kg) that oxidized and made the soil-ash mixtures very acid (pH < 4). Ryegrass grown in unlimed/unfertilized soil-ash mixtures of this ash contained very high concentrations of Al, B, Cd, Co, Mo, Ni, and Zn (up to 2449, 97, 24, 38, 5, 532, and 1109 mg/kg, respectively). Many of these concentrations were considered to be phytotoxic and/or sufficiently high to be toxic to animals under continuous long-term grazing conditions. However, applications of the same gasifier ash to soils that were limed and fertilized with N, P, and K produced ryegrass that did not contain phytotoxic levels of any of the trace elements examined or concentrations that would be of concern in the transport of these metals along food chains to man. Risk was related to soil pH, a factor that can be managed with proper liming and fertilizing practices.