Pond Ash Research Articles

Soil versus Pond Ash Surfacing of Feedlot Pens: Occurrence of Escherichia coli O157:H7 in Cattle and Persistence in Manure.

Reducing Escherichia coli O157:H7 in cattle and their manure is critical for reducing the risk for human foodborne and waterborne illness. The objective of this study was to evaluate the effects of soil and pond ash surfaces for feedlot pens on the prevalence, levels, and/or persistence of naturally occurring E. coli O157:H7 and total E. coli in cattle (feces and hides) and manure. Cattle (128 beef heifers) were sorted among 16 pens: 8 surfaced with soil and 8 surfaced with pond ash. The prevalence of E. coli O157:H7 in feces decreased (P < 0.0001) during the study from 57.0% on day 0 to 3.9% on day 84 but did not differ (P > or = 0.05) between cattle on soil and on pond ash pens at any sampling period. The prevalence of the pathogen on hides and in feedlot surface material (FSM) also decreased (P < 0.0001), with no effect of soil or pond ash surface (P > or = 0.05). Similarly, levels of E. coli in FSM did not differ (P > or = 0.05) at any sampling period, and there were no clear trends for survival differences of E. coli O157:H7 or E. coli in FSM between pond ash and soil surfaces, although E. coli populations survived at 5.0 log CFU/g of FSM on the pen surfaces 6 weeks after the cattle were removed. These results indicate that housing cattle on pens surfaced with pond ash versus pens surfaced with soil does not affect E. coli O157:H7 in cattle or their manure.

English

The use of coal combustion by-products (CCBs) in mine reclamation has been advocated by some because of their low permeability and potential to generate alkalinity. However, others have argued that these benefits are outweighed by the potential for leaching of trace elements that can enter ground and surface waters. In 1996, an abandoned mine land (AML) site in southwestern Indiana was reclaimed using ponded ash as structural fill in highwall cuts, and fixated scrubber sludge (FSS) as capping material over pyritic refuse. Pre- reclamation and post-reclamation monitoring of surface water discharge from the site, groundwater elevations and chemistry, as well as soil moisture fluctuations in the unsaturated zone have provided a basis for evaluating the effects of CCBs on the hydrochemistry of the site and potential for off-site impacts. Limited recharge through the FSS is supported by barometric efficiency changes in the refuse aquifer, the presence of perched water measured in monitoring wells installed on the cap, and minimal fluctuations in soil moisture within and immediately below the cap. Reductions in oxygenated rainwater reaching the refuse are indicated by groundwater chemistry data, collected from the refuse aquifer between 1995 and 2007, which show an increase in pH along with decreasing trends in total acidity, specific conductivity (SpC), and arsenic. Concentrations of boron, a trace element commonly associated with CCBs, have declined to near pre-reclamation levels at most sites (~1 mg/L) after an increase immediately following reclamation. Although arsenic concentrations at 14 µg/L (EPA maximum contaminant level, or MCL, is 10 µg/L) along with boron (14 mg/L) remain slightly elevated in groundwater associated with ash-filled lakes, improvements in surface water quality leaving the site include significant reductions in total mineral acidity and total iron concentrations, while trace metal concentrations remain below EPA MCLs.

Shear Behaviour of Loose and Compacted Pond Ash

Massive utilization of pond ash in earth works requires thorough understanding of its geotechnical characteristics, especially strength characteristics. Here in this paper, a detailed experimental study carried on the strength and other geotechnical characteristics of pond ash samples, collected from inflow and outflow points of two ash ponds in India, are presented. Strength characteristics were investigated using consolidated drained (CD) and undrained (\( \overline{\text{CU}} \)) triaxial tests with pore water pressure measurements, conducted on loose and compacted specimens of pond ash samples under different confining pressures. Ash samples from inflow point exhibited behaviour similar to sandy soils in many respects. They exhibited higher strengths than reference material (Yamuna sand), though their specific gravity and compacted maximum dry densities are significantly lower than sands. Ash samples from outflow point exhibited significant differences in their properties and values, compared to samples from inflow point. Shear strength of the ash samples from outflow point are observed to be low, particularly in loose state where static liquefaction is observed.

Heavy Metal Pollution in Lentic Ecosystem of Sub-Tropical Industrial Region and its Phytoremediation

Metals and several physicochemical parameters, from four sampling sites in a tropical lake receiving the discharges from a thermal power plant, a coal mine and a chlor-alkali industry, were studied from 2004–2005. Pertaining to metal pollution, the site most polluted with heavy metals was Belwadah, i.e., waters and sediments had the highest concentration of all the metals examined. The reference site was characterized by the presence of low concentrations of metals in waters and in sediments. Further, several wetland plants were harvested from different sites, and simultaneously, these were assessed for their metal concentration efficiency. Following the water quality monitoring and metal concentration efficiency, two-month field phytoremediation experiments were conducted using large enclosures at the discharge point of different polluted sites of the lake. Eichhornia crassipes, Lemna minor, and Azolla pinnata were frontier metal accumulators hence selected for previously mentioned field phytoremediation experiments. During field phytoremediation experiments using aquatic macrophytes, marked percentage reduction in metals concentrations were recorded. The percentage decrease for different metals was in the range of 25–67.90% at Belwadah (with Eichhornia crassipes and Lemna minor), 25–77.14% at Dongia nala (with Eichhornia crassipes, Lemna minor, and Azolla pinnata) and 25–71.42% at Ash pond site of G.B. Pant Sagar (with Lemna minor and Azolla pinnata). Preliminary studies of polluted sites are therefore useful for improved microcosm design and for the systematic extrapolation of information from experimental ecosystems to natural ecosystems.

Liquefaction behaviour of loose and compacted pond ash

Most of the ash produced all over the world is primarily disposed off by wet disposal method onto the ash ponds, which are occupying huge valuable lands. This disposal problem can be minimized by utilizing ash in large geotechnical earthworks. However, its use in earthquake prone areas requires thorough understanding of its liquefaction resistance and nature of development of excess pore pressures under dynamic loading conditions. Investigations have been carried out in this paper on the liquefaction behaviour of pond ash by conducting cyclic triaxial tests on inflow and outflow ash samples collected from two different ash ponds. Distinctly different liquefaction phenomenon was observed for the ash samples from inflow and outflow points of the same ash pond. Inflow samples exhibited higher cyclic resistance than outflow samples and their strengths were comparable with the natural sands. Further studies revealed that the influence of various factors on liquefaction susceptibility of both the types of ashes is similar to that of natural sands.

The Beat

Vol. 118, No. 3 NewsOpen AccessThe Beat Erin E. Dooley Erin E. Dooley Search for more papers by this author Published:1 March 2010https://doi.org/10.1289/ehp.118-a116bAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit EPA Releases Utilities’ Plans for Coal Ash Impoundment SafetySince the December 2008 collapse of the Kingston Fossil Plant coal ash impoundment in Tennessee, which spilled 5.4 million yd3 of ash into the Emory River, the U.S. EPA has been conducting on-site assessments of impoundments at electric utilities across the country. On 4 February 2010 the agency released plans submitted by 22 utilities that detail how they are making their coal ash ponds safer through measures such as adding riprap and vegetation to strengthen earthen impoundment walls. In a press release the EPA said it is “continuing to review the reports and technical recommendations, and is working with the facilities to ensure that the recommendations are implemented in a timely manner.Erosion monitoring and control are key elements of several utilities’ plans.Rating the Sustainability of RoadsIn January 2010 the University of Washington and engineering firm CH2M Hill released Greenroads™, a new system that rates the sustainability of road design and construction projects similarly to how programs such as LEED® rate and certify buildings. Minimum requirements for Greenroads certification include a noise mitigation strategy and a life cycle energy and emissions analysis for paving materials. Extra points are awarded for voluntary measures such as avoiding light pollution, using permeable pavements to reduce stormwater runoff, and adding lanes for bicycles and pedestrians.New Lighting from NanofibersRTI International has developed a novel lighting technology that it says is 5 times more energy-efficient than incandescent bulbs and, unlike compact fluorescent lamps (CFLs), uses no mercury-containing components. RTI’s new technology, which was partially funded by the Department of Energy, pairs high-performance nanofiber-based reflectors with photoluminescent nanofibers to create light its developers say has better color rendering properties than is typically found with CFLs. The new technology could hit the market within 3–5 years.What Cd Means to CVDA study by Junenette Peters and colleagues in the February 2010 issue of Environmental Research adds evidence to the idea that exposure to low levels of cadmium may be linked to cardiovascular disease. Using data from the National Health and Nutrition Examination Survey, the team found that a 50% increase in blood cadmium was associated with a 35% increase in stroke prevalence and a 48% increase in heart failure prevalence, while the same change in urinary cadmium was associated with 9% and 12% increases, respectively. Although smoking explained their findings in part, the researchers believe other exposures to cadmium, such as through food and metal and ceramic food containers, should be considered in both research and risk assessment for cardiovascular diseases.Low-level cadmium exposure may contribute to cardiovascular disease.China Completes First National Pollution CensusOn 9 February 2010 the Chinese government announced it had completed the country’s first national census of pollution, a 2-year effort by almost 600,000 staff that mapped nearly 6 million pollution sources. This survey is the first time Chinese environmental authorities have been able to include agricultural sources of pollution in their data. Among other applications, these findings will help guide China’s next 5-year environmental protection plan to begin in 2011. However, the full survey results are available only to selected government officials. Environmental advocates are calling for the government to release details of the survey to the public.Communities Warm Up to Woodstove Changeout ProgramsAs part of the U.S. EPA’s Great American Woodstove Changeout campaign, more than 45 U.S. communities now provide financial incentives to residents who trade in old stoves for newer, less polluting models or pellet, gas, or propane appliances. Many of the older woodstoves in use can emit up to 10 times as much particulate matter as newer stoves, according to the EPA. As of January 2010, the agency estimated more than 13,000 woodstoves and fireplaces had been replaced under such programs, saving an estimated 248 tons of particulate matter emissions and $84 million in health benefits per year.FiguresReferencesRelatedDetails Vol. 118, No. 3 March 2010Metrics About Article Metrics Publication History Originally published1 March 2010Published in print1 March 2010 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Improvement in liquefaction resistance of pond ash using stone-sand columns

Aim of this paper is to demonstrate improvement in liquefaction resistance of the pond ash (fly ash) due to its strengthening with stone-sand columns. Tests were carried out on a vibration table (shake table) to evaluate the liquefaction resistance of the pond ash without and with stone-sand columns. In the present study, the liquefaction resistance is evaluated in-terms of pore pressure ratio (<i>r_u</i>). The effects of spacing of stone-sand columns on liquefaction resistance of the pond ash have been studied. Tests results indicate that the addition of stone-sand columns increases the liquefaction resistance of the pond ash significantly. Further, increasing the number of stone-sand columns, the liquefaction resistance of the pond ash increases considerably. This also decreases significantly the time for building-up of maximum pore pressure; duration for which maximum pore pressures stays and total time for dissipation of pore water pressure which indicates decrease in drainage path. The proposed technique of improvement is simple and has very much practical significance.

Comparative Study of Leachate Characteristics of Pond Ash from Long‐Term Leaching and Ash Pond Disposal Point Effluent from Chandrapura Thermal Power Station, India

The present paper deals with the leaching characteristics of coal combustion residues from chandrapura thermal power station, Jharkhand, India. The study was made under the laboratory as well as the field condition. From the laboratory study conducted so far it is hereby concluded that the leachates of coal combustion residues from chandrapura thermal power station with respect to potentiometric and trace elements analysis are within the permissible limits as per Indian Standards (IS:2490). From the study it is also found that the elements such as arsenic, boron, nickel, etc. could not be detected. The discharge point leachate also does not pose any environmental problem from the point of view of leaching of trace and/or toxic elements as per IS: 2490.

Large-Scale Nonlinear Conjunctive Use Optimization Problem: Decomposition Algorithm

A cyclic storage (CS) system is defined as physically-integrated and operationally interconnected surface water and groundwater subsystems with full direct interactions between the subsystems. The proposed definition treats surface and subsurface impoundment subsystems as competing and potentially interconnected parallel storage facilities that minimize most of the problems associated with large-scale surface impoundments for water supply purposes. This paper emphasizes on the development and implementation of a hybrid two-stage genetic algorithm (GA)-linear programming (LP) algorithm to optimize the design and operation of a nonlinear, nonconvex, and large-scale semidistributed, CS system in an irrigable area. Performance of the proposed model is tested with a 240-period problem where other approaches failed to locate a feasible solution. For optimal operation of the system, a set of operating rules are developed for the joint utilization of surface and subsurface storage capacities to meet a predefined ...

Balancing Act: Creating the Right Regulation for Coal Combustion Waste

With the 22 December 2008 collapse of a Tennessee Valley Authority (TVA) ash pond in Kingston, Tennessee, and the arrival of the Obama administration the following month, the regulatory ground is shifting in regards to coal combustion waste (CCW), the millions of tons of waste left over each year from burning coal for electricity. The U.S. Environmental Protection Agency (EPA) is pursuing a host of initiatives that could directly or indirectly affect the disposition of CCW. States, too, are revisiting their regulations. The goal of these initiatives is to ensure public health; the challenge is to do so without compromising a recycling industry that the American Coal Ash Association (ACAA) says keeps about 56 million tons of CCW per year out of the landfilled waste stream.

Element mobility from fresh and long-stored acidic fly ashes associated with an Australian power station

Abstract The mobility of major and trace elements in a series of ashes from pulverised coal combustion, stored in dams and similar repositories for up to 25 years, has been investigated. Comparison with the mobility of the same elements from equivalent fresh, dry ash material has been used to provide a basis for assessing the long-term changes in element mobility during ash storage. Laboratory testing at different initial pH values indicates an increase in the natural (acidic) pH and a decrease in the buffering capacity of the ash by contact with water during handling and storage, suggesting loss of components such as SO 4 from the surfaces of the ash particles with even relatively brief water contact. Most elements show lesser degrees of mobility from ashes that have been stored under water, even if only for a relatively short period, than from the fresh dry material. There are, however, some exceptions, such as Mo, which appear to have increased mobility from the longer-stored ashes due to a progressive rise in pH levels. Relatively little difference is noted between the mobility of most elements in the water-stored ashes, regardless of whether they were only recently emplaced or have been in the dam for 20 years or more. This suggests that equilibrium has been established between the ash and the pore water, and that once the readily leached fraction had been removed the ash–water system remained relatively stable with time. Ash that had been deposited under water in a trial ash pond and then drained and exposed to dry storage conditions for many years, however, showed many similar leaching characteristics to the fresh dry ash material. This suggests that at least some elements or ions (e.g. SO 4 2− ) may be re-adsorbed on to the ash particles with exposure after drying, or that additional elements of similar characteristics may be released, allowing a new set of equilibrium conditions to be established. The concentrations of most elements in the laboratory test leachates are of a similar order of magnitude to the concentrations of the same elements in the water in the present-day ash pond. This increases confidence in the use of laboratory tests to provide guidance on the expected behaviour of ash when exposed to water in actual field situations.

Bulk use of pond ash for cultivation of wheat–maize–eggplant crops in sequence on a fallow land

In India, presently 85 existing thermal power plants (TPPs), contributing to about 70% of the total energy requirement, produce 118 million tons of fly ash per year. This huge quantity of fly ash not only poses serious problems of environmental concerns but occupies large areas of land for its dumping and needs urgent and appropriate measures for its safe disposal and gainful utilization on sustainable basis. Besides, reclamation of a vast area of uncultivated wasteland for agriculture and forestry is another challenge for the fast-growing population of the country. A field experiment was conducted to evaluate the effect of pond ash application on the yield and nutrient composition of wheat, maize and eggplant crops grown in sequence on an uncultivated fallow land. Pond ash collected from the Anpara TPP, India was mixed with soil at 100 t ha −1. Ash application had a beneficial effect on the wheat yield. Addition of pond ash resulted in a significant increase in the contents of N, P, K, S, Ca, Mg, and micro-nutrients. The uptake of toxic trace elements (Pb, Se, Cr, and Cu) was below the threshold levels. The residual effect of ash on crop yield and nutrient composition of the subsequent maize and eggplant crops were also significant. The overall beneficial effect of pond ash on crops could be attributed to the improvement in the soil physical quality due to ash amendment. The results indicated that pond ash could be applied safely for reclamation of uncultivated fallow soils.

Deposition characteristics of coal ash slurries at higher concentrations

High concentration slurry disposal system (HCSD) for transportation of coal ash to ash ponds from coal fired thermal power plants using pipelines has emerged as an economical and environmental friendly method. Coal Ash in slurry form is deposited in the ash pond and hence the deposition characteristics at higher concentrations ( C w >60% by weight) are very important. The settled solid profile in the ash pond at high concentrations is of great interest to the ash pond designers. The present study is an attempt to establish the relationship between the settled solid profile and the physical/rheological properties of coal ash slurry at high concentrations. The settled solid profile is experimentally measured in terms of cone angle for slurries of fly ash as well as mixture of fly ash (FA) and bottom ash (BA) in the ratio of 4:1 at high concentrations. The values of cone angle if the slurries are poured on either a pervious or impervious bed have also been measured. The results obtained from the experiments show that the cone angle depends on rheological properties like yield stress and Bingham plastic viscosity which in turn depend on various properties like solid concentration, particle size distribution etc. Also, cone angle for fly ash slurry is higher than that for the mixture of FA and BA slurry at any given concentration. Further, it was also observed from the experiments that cone angle is higher for pervious bed as compared to impervious bed for both types of slurries.

Studies of lagoon ash from Sarawak to assess the impact on the environment

Coal utilization, mainly in thermal power plants, has increased significantly from 4.2 to 13 million tonnes within 2000 to 2005, which resulted in the production of approximately 2 million tonnes of coal ash in Malaysia. Of this only a small percentage is used as a cement ingredient, in concrete industry, as a fill material, etc. and with the rest of the amount being disposed in ash ponds or lagoons. If the lagoons are not properly designed with a landfill liner or if there is spillage from the ash pond, the toxic heavy metal present in coal ash can result in the contamination of the subsurface soil and the ground water. The concentration of heavy metals or trace elements in coal residues depends on the composition of a particular parent coal and the bulk utilization of lagoon ash for various purposes requires a complete characterization of the ash. Hence, this paper analyzes the coal ash for its trace element content and characterizes mainly physical, chemical, mineralogical, morphological and thermal properties of the lagoon ash from a local coal based thermal power plant from Sarawak, Malaysia. The results also indicated that, the concentration of some trace elements is quite high from the environmental perspective in this particular lagoon ash.

Compaction Characteristics and Bearing Ratio of Pond Ash Stabilized with Lime and Phosphogypsum

Recycling of waste material is one of the effective solutions of its disposal problem. Fly ash produced by coal-based thermal power plants and phosphogypsum (PG) produced by fertilizer plants producing phosphoric acid as constituent of fertilizers, take huge disposal area and creates environmental problems. Stabilization/solidification of fly ash improves the engineering properties and reduces the environmental problem like leaching and dusting. This paper presents the laboratory test results of a Class F pond ash alone and stabilized with varying percentages of lime (4, 6, and 10%) and PG (0.5, and 1.0), to study the suitability of stabilized pond ash for road base and subbase construction. Standard and modified Proctor compaction tests have been conducted to reveal the compaction characteristics of the stabilized pond ash. Bearing ratio tests have been conducted on specimens, compacted at maximum dry density and optimum moisture content obtained from standard Proctor compaction tests, cured for 7, 28, and 45 days. Both unsoaked and soaked bearing ratio tests have been conducted. This paper highlights the influence of lime content, PG content, and curing period on the bearing ratio of stabilized pond ash. The empirical model has been developed to estimate the bearing ratio for the stabilized mixes through multiple regression analysis. Linear empirical relationship has been presented herein to estimate soaked bearing ratio from unsoaked bearing ratio of stabilized pond ash. The experimental results indicate that pond ash-lime-PG mixes have potential for applications as road base and subbase materials.

Chromium and nickel migration study through fine grained soil

A comprehensive laboratory-scale investigation was carried out to explore the toxic metal attenuation capacity of a field clay sample collected from adjoining areas of an ash pond site of a Super Thermal Power Plant in West Bengal, India. The existence of two major elements viz., Cr 6+and Ni 2+ in excess to permissible limit was observed in soil and water samples collected from the site. Batch kinetic performance results exhibited reasonable Cr 6+and Ni 2+ uptake capacity of soil in equilibrium condition. The experimental data also fitted well in Freundlich isotherm model. The adsorption behaviour of above pollutants in both vertical and horizontal directions through soil was explored. The results showed that more than 80% of Ni and 72% of Cr were found to be sorbed by the soil. Breakthrough adsorption study also showed a good metal adsorption capacity of soil.

Phytoremediation of heavy metals in a tropical impoundment of industrial region

Aquatic pollution poses a serious challenge to the scientific community worldwide, since lakes or reservoirs find multifarious use and most often their water is used for drinking, bathing, irrigation, and aquaculture. Nine metals and several physicochemical parameters, from four sampling sites in a tropical lake receiving the discharges from a thermal power plant, a coal mine, and a chlor-alkali industry, were studied from 2004 to 2005. Pertaining to metal pollution, the site most polluted with heavy metals was Belwadah, i.e., waters and sediments had the highest concentration of all the metals examined. The reference site was characterized by the presence of low concentrations of metals in waters and sediments. Following the water quality monitoring, 2-month field phytoremediation experiments were conducted using large enclosures at the discharge point of different polluted sites of the lake. During field phytoremediation experiments using aquatic macrophytes, marked percentage reduction in metals concentrations were recorded. The percentage decrease for different metals was in the range of 25% to 67.90% at Belwadah (with Eichhornia crassipes and Lemna minor), 25% to 77.14% at Dongia nala (with E. crassipes, L. minor and Azolla pinnata), and 25% to 71.42% at Ash pond site of G.B. Pant Sagar (with L. minor and A. pinnata). Preliminary studies of polluted sites are useful for improved microcosm design and for the systematic extrapolation of information from experimental ecosystems to natural ecosystems.

Effect of randomly distributed geofibers on the piping behaviour of embankments constructed with fly ash as a fill material

Today, fly ash is being used as a structural fill material in highway and railway embankments, for ash pond bunds, levees, filling low-laying areas etc. Seepage induced failures in the form of piping can weaken and affect the performance of an embankment constructed with fly ash as a structural fill material. This paper presents a study to examine the effect of randomly distributed geofibers on the piping behaviour of fly ash. In this study, a number of experiments were carried out for determining the seepage velocity and piping resistance of fly ash, mixed randomly with flexible polyester fibers having various dosages and lengths. Seepage velocity of flow of water through fly ash is calculated for each case and compared with an unreinforced fly ash. It was observed that fibers reduced the seepage velocity, increased the piping resistance of fly ash and delays the attenuation of piping phenomena considerably. Finally the mechanism by which discrete and randomly distributed fibers restrain piping of fly ash is explained with the fly ash fiber interaction.

Mechanisms of Neutralization of Bauxite Residue by Carbon Dioxide

Bauxite residue (red mud), an alkaline slurry from alumina refining, is produced in large volumes and disposed of in large surface impoundments. The objectives of this study were to measure the extent of neutralization of bauxite residue by carbon dioxide as a function of CO2 partial pressure and to determine the geochemical reactions responsible for carbon sequestration. Bauxite residue was exposed to carbon dioxide (CO2) at partial pressures ranging from 10−3.5to1atm and the residue pore-water pH was measured until a steady state pH was achieved. Using pure CO2(PCO2=1atm), a steady state pH of 7.7 was established in 1day while it took 9days to reach a pH of 9.8 at PCO2=10−3.5atm. The pH rebounded to 9.9 after 1day when bauxite residue first neutralized at PCO2 of 1, 0.1, or 0.01atm for 10days was subsequently exposed to PCO2=10−3.5atm, indicating that the pH change during short-term carbonation (t⩽10days) was due to reactions of carbonic acid and OH− in the pore water. A longer reaction time (30days) at PCO2=1atm indicated carbonation of tricalcium aluminate (C3A solid) and conversion to calcite. This was confirmed in aged field samples that had been carbonated in air (PCO2=10−3.5atm) for 30years. The maximum solid-phase CO2 sequestration (as calcite) potential of red mud can be realized at PCO2=10−3.5atm; however, the sequestration rate is limited by slow dissolution of C3A. The CO2 sequestration potential is small (0.029–0.057 MMT CO2∕year) compared to annual CO2 emissions (110MMT∕year) for bauxite refining and red mud production of 30MMT∕year.

Nutrient and Bacterial Transport in Runoff from Soil and Pond Ash Amended Feedlot Surfaces

The addition of pond ash (fly ash that has been placed in evaporative ponds and subsequently dewatered) to feedlot surfaces provides a healthier environment for livestock and economic advantages for the feedlot operator. However, the water quality effects of pond ash amended surfaces are not well understood. The objectives of this field investigation were to: (1) compare feedlot soil properties, and nutrient and bacterial transport in runoff, from pond ash amended surfaces and soil surfaces; (2) compare the effects of unconsolidated surface materials (USM) (loose manure pack) and consolidated subsurface materials (CSM) (compacted manure and underlying layers) on nutrient and bacterial transport in runoff; and (3) determine if the measured water quality parameters are correlated to soil properties. Simulated rainfall events were applied to 0.75 m wide 2 m long plots with different surface materials and surface conditions. Measurements of calcium, magnesium, sulfur, and pH were found to be significantly greater on the pond ash amended surfaces. In comparison, the soil surfaces contained significantly greater amounts of Bray 1-P. The runoff load of NH4-N was significantly greater on the pond ash amended surfaces, while the total phosphorus (TP) load was significantly greater on the soil surfaces. The NO3-N and total nitrogen (TN) loads in runoff were significantly greater on the feedlot surfaces containing CSM. Concentrations of E. coli in runoff were similar on the pond ash amended surfaces and soil surfaces. The dissolved phosphorus (DP), particulate phosphorus (PP), and TP load of runoff were all significantly correlated to Bray 1-P measurements.