Coal Ash Disposal Research Articles

Impact of leaching procedure on heavy metals removal from coal fly ash

In this work, removal of heavy metals (Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb) from fly ash has been studied using acid leaching and wet oxidation methods. In parallel, microwave-assisted acid digestion was applied for determination of pseudo-total concentrations of heavy metals to estimate the leaching efficiency. Multivariate statistics (Pearson correlation, principal component analysis, and hierarchical cluster analysis) have shown two dominant groups of elements, depending on their characteristics and affinity towards the ash solid phase. Thus, Cr, Zn, Mn, Co, and Ni belong to the group I, while Pb, As, Cd, and Cu belong to the group II. It was demonstrated that the wet oxidation method was more suitable than acid leaching since the reduction in metal concentration was 30 to 75 % compared to 12 to 25 % obtained by acid digestion. The influence of fly ash treatment on the residue characteristics was investigated by X-ray diffractometry and scanning electron microscopy. The analyses revealed surface and structure changes of fly ash after the wet oxidation treatment. Overall, wet oxidation could be an appropriate treatment for heavy metal removal from fly ash, providing a material that could be further used, thus reducing the risk of pollution caused by the disposal of coal combustion fly ash.

Subsidence of a Coal Ash Landfill in a Power Plant Observed by Applying PSInSAR to Sentinel-1 SAR Data

We analyzed ground subsidence at the coal ash disposal sites of Stanton Energy Center, a power plant located in Orlando, Florida, USA, by applying 157 Sentinel-1 SAR images obtained between May 2017 and December 2022 in ascending orbit to the PSInSAR technique. A LiDAR DEM with 1 m posting was used for the DInSAR and StaMPS processing for PSInSAR. The results showed significant ground subsidence on the area where solar panels were installed on top of the coal ash landfill. The coal ash landfill was divided into three sites (A, B, and C) according to the landfill sequence. The spatially averaged PSInSAR showed subsidence rates of 7.3 mm/year, 6.2 mm/year, and 8.8 mm/year in sites A, B, and C, respectively. In particular, relatively newly deposited sites A and B showed a decreasing trend in subsidence rate with higher quadratic components in regression function, indicating a stabilization of the subsidence. On the other hand, the oldest site C exhibited the highest (and a relatively constant) subsidence rate, suggesting that the settlement occurred earlier and is now at a constant rate. It is also suspected that new dumping activity near C might have caused a higher subsidence rate than in sites A and B. No subsidence occurred at other solar panel installations on the ground outside the landfill, suggesting that the subsidence was caused by the gravitational compaction of the landfill materials rather than by the instability of the solar facilities. Comparison of PSInSAR results with lower resolution DEMs, such as SRTM and Copernicus DEM, showed range errors of the PS positions proportional to the height deviation from LiDAR DEM, highlighting the importance of accurate DEMs for the time-series analysis of SAR data.

Isotopic Signatures and Outputs of Lead from Coal Fly Ash Disposal in China, India, and the United States.

Despite extensive research and technology to reduce the atmospheric emission of Pb from burning coal for power generation, minimal attention has been paid to Pb associated with coal ash disposal in the environment. This study investigates the isotopic signatures and output rates of Pb in fly ash disposal in China, India, and the United States. Pairwise comparison between feed coal and fly ash samples collected from coal-fired power plants from each country shows that the Pb isotope composition of fly ash largely resembles that of feed coal, and its isotopic distinction allows for tracing the release of Pb from coal fly ash into the environment. Between 2000 and 2020, approx. 236, 56, and 46 Gg Pb from fly ash have been disposed in China, India, and the U.S., respectively, posing a significant environmental burden. A Bayesian Pb isotope mixing model shows that during the past 40 to 70 years, coal fly ash has contributed significantly higher Pb (∼26%) than leaded gasoline (∼7%) to Pb accumulation in the sediments of five freshwater lakes in North Carolina, U.S.A. This implies that the release of disposed coal fly ash Pb at local and regional scales can outweigh that of other anthropogenic Pb sources.

Experimental Validation of Reinforced Concrete Beam Incorporating Coal Fly Ash and Coal Bottom Ash Using Numerical Analysis

The environmental deterioration affected by the disposal of Coal Bottom Ash (CBA) from power stations has worsened as the energy demand has increased. In addition, the increased demand for concrete leads to an increase in aggregate consumption, which contributing to the depletion of natural resources. To prevent the immense amount of CBA waste and the destruction of natural resources, an initiative has been implemented to replace aggregate with CBA in concrete. The Reinforced Concrete (RC) beams underwent a four-pointbending test. The test was done after 28 days of curingage. Therefore, this study was conducted to study the performance of RC beam incorporating CBA as fine and coarse aggregate replacement. The deflection, maximum load and cracking pattern of RC beam were determined. Beam with 100% coarse coal bottom ash 100% fine coal bottom ash resulted to the maximum load at 88 kN with maximum deflection at 18.87 mm. The RC beams were redesigned using the three-dimensional nonlinear simulation software ABAQUS in enable to identify and compare the simulation and experimental findings. The FEA result shows that ultimate load of FEA waswithin 5% range with the experimental results. The simulation results demonstrated that the proposed finite element model accurately predicted the RC beam’s damage behaviour.

Comparison of Different Radiological Risk Assessment Scenarios at a Coal Ash and Slag Disposal Site

Coal fly ash and slag waste residuals from coal combustion are an issue of importance as one of the possible sources of environmental contamination and exposure to NORM. This study compares the results of different radiological risk assessment scenarios targeting terrestrial biota at a legacy site in Croatia that contains large quantities of coal ash with an enhanced content of radionuclides originating from previous industrial activities. The ERICA assessment tool was used for a risk assessment, which included data from borehole samples with a maximum depth of 6 m and trees as the primary reference organisms. The results of the risk assessments from various depth ranges found the radiological risk to the reference organisms to be negligible, regardless of the depth range, since the screening dose rate of 10 µGyh−1 was not exceeded in any of the assessments. The risk assessment results from all depth ranges show higher total dose rate predictions when the tool’s default CR values are used, compared to the site-specific ones, which is in agreement with previous studies on the application of the ERICA tool. A comparison of results from different spatial radiological risk assessments showed that sample depth does not affect the estimated total dose rate to biota.

Current state of the coal ash handling problem in Russia and abroad, aspects of the coal ash applications in hydrogen economy

One of the global state tasks, contributing to the implementation of the goal of developing the energy sector of the Russian Federation and given in the Energy Strategy of the Russian Federation for the period until 2035, is to reduce the negative impact of the fuel and energy complex industries on the environment.In this regard, special attention is paid to the coal ash handling problem, which is intensified by tightening of the environmental legislation with the transition to the principles of the best available technologies, greening of the coal power, depletion of the capacity of the coal ash disposal sites, etc. Disposal of ash, slag, ash-and-slag mixtures, formed at combustion of coal, peat and shale, is one of the main problems of the modern solid-fuel thermal power plants in Russia, the number of which makes 172. The average age of the coal-fired TPPs is about 50 years that significantly affects the technical and environmental performance of the ash removal system of TPPs. At the Russian TPPs for the ash and slag conveying hydraulic ash removal systems are the most common, used in the vast majority of cases being technically outdated, uneconomical and ecologically not friendly.Annually 25 … 30 million tons of ash and slag are formed at the coal-fired power plants of the Russian Federation. Currently more than 1.5 billion tons of ash and slag are accumulated at the ash disposal sites of thermal power plants, and every year these figures are growing. About 2/3 of all ash and slag disposals are close to the design filling or are already overfilled. Elimination of objects of the accumulated environmental damage, representing ash disposals of the coal-fired power plants, is one of the conditions for Russia's transition to the standards of “green” economy. The problem of coal-fired power plants in terms of elimination of the accumulated environmental damage can be solved only by implementing the large-scale projects of integrated coal ash processing, obtaining required products.The article provides statistical data for the 2019 relating to the volumes of the coal ash generation and utilization in various countries of the world. An overview of the various applications of the coal combustion by-products, the main of which are ash and slag, in Russia, India, China, EU countries, etc. is presented. The article contains data on the applicability of the coal ash for various technologies of its use according to the Russian Ministry of Energy. A review of scientific and technical information sources on the prospects of using coal ash in hydrogen power engineering for hydrogen sorption and storage is given, as well as a review of traditional methods of hydrogen storage. Terminology in the field of coal ash handling found in scientific and technical information sources is considered, and a classification of coal combustion by-products in Russia and abroad is given. The main recommendations of the author, contributing to the increase in the use of coal ash in Russia, are given.

Effects of the T-abrupt exit configuration of riser on fuel properties, combustion characteristics and NOx emissions with coal self-preheating technology

NOx generated from coal combustion brings about severe environmental problems. Among many combustion technologies, coal self-preheating combustion technology is valued for its great potential of low NOx combustion, while in-depth studies on the structure of the self-preheating device (SPD) have not been carried out, which makes it difficult to further reduce NOx. In addition, disposal of coal gasification fly ash (CGFA), a kind of solid waste, is still mainly dissipated in landfills, resulting in the pollution of soil, water and wastes energy. In order to optimize the SPD structure for further reducing NOx and provide technical support for the engineering utilization of CGFA, the properties of preheated fuel (coal gas and coal char), the behavior characteristics of combustion and NOx emission under different He/Hr (the ratio of projected height to the riser height) were investigated on a 30 kW bench-scale test rig. Stable and high efficient MILD combustion was achieved without manifest flame front. The results revealed that appropriate increase of He/Hr ratio was conducive to the release of fuel-N during preheating, facilitating the conversion of fuel-N to N2. For BC and CGFA, the pre-removal effect of fuel-N in the SPD reached the best when He/Hr ratio was 3/8 and 1/4, respectively. The increase of He/Hr ratio was not salutary to improving the combustion reactivity of BC, while for CGFA, the modification effect on the combustion reactivity of coal char could reach the best when He/Hr ratio = 1/4. Both NOx emission and the conversion ratio of fuel-N to NOx of BC and CGFA could reach the optimal value when He/Hr ratio was 1/4.

Legacy of Coal Combustion: Widespread Contamination of Lake Sediments and Implications for Chronic Risks to Aquatic Ecosystems.

Elevated concentrations of toxic elements in coal ash pose human and ecological health risks upon release to the environment. Despite wide public concerns about water quality and human health risks from catastrophic coal ash spills and chronic leaking of coal ash ponds, coal ash disposal has only been partially regulated, and its impacts on aquatic sediment quality and ecological health have been overlooked. Here, we present a multiproxy approach of morphologic, magnetic, geochemical, and Sr isotopic analyses, revealing unmonitored coal ash releases over the past 40 to 70 years preserved in the sediment records of five freshwater lakes adjacent to coal-fired power plants across North Carolina. We detected significant sediment contamination and potential chronic ecological risks posed by the occurrence of hundreds of thousands of tons of coal ash solids mainly resulting from high-magnitude stormwater runoff/flooding and direct effluent discharge from coal ash disposal sites. The proximity of hundreds of disposal sites to natural waterways across the U.S. implies that such contamination is likely prevalent nationwide and expected to worsen with climate change.

Does exposure to weathered coal ash with an enhanced content of uranium-series radionuclides affect flora? Changes in the physiological indicators of five referent plant species

Coal ash deposited in open landfills is a potential source of environmental pollutants due to the contained toxic element content. The weathered coal ash used in this study additionally contains enhanced activity concentrations of 238U series radionuclides. This study aimed to determine the physiological effects of enhanced ionizing radiation and toxic elements on five plant species (smilo grass, sticky fleabane, blackberry, mastic and pine tree) inhabiting the coal ash disposal site. Among the potentially toxic measured elements, contents of Sb, As and especially V significantly exceeded their respective levels at the control site, as well as the content of 238U and its progenies. Significant changes in photosynthetic pigments were recorded following chronic exposure to the plants growing on the coal ash site. Different responses were also observed in the plant species regarding the activity of catalase and glutathione-S-transferase (GST). The level of lipid peroxidation markedly increased in plants from the disposal site, except in blackberry, wherein GST activity was the strongest, indicating an important role of that enzyme in the adaptation to coal ash pollutants. The results of this study suggest that the modulation of the studied biochemical parameters in plants growing on coal ash is primarily species-dependent.

Divergence in heritable life history traits suggests potential for local adaptation and trade-offs associated with a coal ash disposal site.

Globally, human activities have resulted in rapid environmental changes that present unique challenges for wildlife. However, investigations of local adaptation in response to simultaneous exposure to multiple anthropogenic selection pressures are rare and often generate conflicting results. We used an in situ reciprocal transplant design within a quantitative genetic framework to examine how adaptive evolution and phenotypic plasticity contribute to the persistence of an amphibian population inhabiting an environment characterized by high levels of multiple toxic trace elements. We found evidence of phenotypic divergence that is largely consistent with local adaptation to an environment contaminated with multiple chemical stressors, tied to potential trade‐offs in the absence of contaminants. Specifically, the population derived from the contaminated environment had a reduced risk of mortality and greater larval growth and in the contaminated environment, relative to offspring from the naïve population. Further, while survival in the uncontaminated environment was not compromised in offspring from the contaminant‐exposed population, they did show delayed development and reduced growth rates over larval development, relative to the naïve population. We found no evidence of reduced additive genetic variation in the contaminant‐exposed population, suggesting long‐term selection in a novel environment has not reduced the evolutionary potential of that population. We also saw little evidence that past selection in the ASH environment had reduced trait plasticity in the resident population. Maternal effects were prominent in early development, but we did not detect any trends suggesting these effects were associated with the maternal transfer of toxic trace elements. Our results demonstrate the potential for adaptation to multiple contaminants in a wild amphibian population, which may have facilitated long‐term persistence in a heavily impacted environment.

Delivering negative emissions with BECCS – A Life Cycle Assessment of coal-waste co-firing with CO2 transport and storage

Coal-fired power plants are a major source of the anthropogenic CO2 emissions that drive climate change and associated environmental impacts. Bio-Energy with Carbon Capture and Storage (BECCS) has been identified as a renewable technology with the potential to remove CO2 from the atmosphere, as it refers to power generation through combusting biomass and capturing CO2 in the flue-gas using carbon capture storage (CCS). Wood and paper wastes have gained popularity as biofuels, due in part to their potential benefits as they do not directly compete with other industries for agricultural land and can significantly reduce the quantity of waste diverted to landfills. This study assesses the greenhouse gas (GHG) emissions reduction capability of retrofitting biomass co-firing and CCS technologies to an existing coal-fired power plant, using a Life Cycle Assessment (LCA) approach. The biomass considered in this study is wood-based waste, including paper, cardboard, palletised wood, chipboard, and furniture. The LCA utilises a “cradle-to-grave” approach, incorporating emissions associated with coal mining, procurement, treatment, combustion, and ash disposal. The system boundary excludes upstream emissions from the manufacture of the waste products, as these were considered “avoided products”. Thus, avoided landfill emissions from the disposal of wood-wastes were included as negative emissions. The life cycle GHG emissions of six different scenarios are considered (co-firing ratios of 0%, 5%, and 10%, each with and without CCS). Power-plant characteristics, waste transportation and pipeline transportation distances were based on existing coal-fired power plants at Mt. Piper, Bayswater, and Eraring, in NSW, Australia. Without CCS, co-firing waste at 5% and 10% without CCS only slightly reduced overall emissions (around 1% and 2% respectively) relative to the current coal-fired power arrangement (no co-firing without CCS). On the other hand, implementing BECCS with 10% co-firing can reduce life cycle CO2 emissions by around 80%, and negative life-cycle CO2 emissions are achievable at co-firing ratios above 30%. The life cycle GHG emissions are most sensitive to the energy penalty imposed by CCS on the power plant. At co-firing ratios of 15%, life-cycle CO2 emissions of BECCS are comparable to those of solar PV energy generation. Moreover, at co-firing ratios around 25%, BECCS life-cycle CO2 emissions are competitive with those of nuclear, wind and hydroelectric generation. This highlights how CCS has the ability to make biomass co-firing compare favourably with other renewable or low-emissions alternatives. Although those technologies possess a lower emission intensity than BECCS at co-firing ratios below 15%, if improvements in boiler efficiency and resource recovery continue then this will allow operation at higher co-firing ratios, lowering emissions intensity further. To determine if BECCS should form part of future plans to meet emissions reduction targets, further research into additional sources of suitable waste biomass is recommended.

The Facts of Science & the Values of Social Justice

The Facts of Science & the Values of Social Justice

WITHDRAWN: Effect of coal ash on strength characteristics of clayey silt soil treated with cement

Coal-based thermal power plants produce coal ash as a by-product and the major concern is for handling and disposal of coal ash without adversely affecting the environment. There is a feasibility to utilize the coal ash in an environmentally safe manner in geotechnical engineering applications. To achieve this objective, an experimental investigation was conducted in which coal ash was used as replacement material in soil mixtures. A clayey silt soil was used in this study and class F type coal ash (CA) was blended in different proportions up to 50% by mass of the soil. The testing program comprised characterization of soil and coal ash, compaction tests and California bearing ratio (CBR) tests. The stress–strain and strength characteristics of compacted soil with coal ash and cement were analyzed. The test results showed that all the mixes achieved a higher CBR value than the control specimen. The optimum coal ash contents for clayey silt–coal ash mixes were found as 20% and 50% which showed higher CBR value, it could be due to the packing effect and imparting cohesion, respectively. The minimum cement content of 1% to the optimum mixes provided a significant improvement in CBR values of 25.19% and 29.14% as compared to the control specimen of 4.72%. These results are acceptable values and hence, the coal ash blended soil is found to be suitable for pavement subgrade and embankments constructions.

Leaching of hazardous elements from Mozambican coal and coal ash

Large-scale coal mining is being carried out in Tete province, Mozambique. This area is also being planned to become a large coal fired power production hub serving electricity to neighboring countries in southern Africa. Thus, huge amounts of coal will be burned, resulting in the generation of a large quantity of coal ash. High concentrations of hazardous elements are often released from coal and coal ash causing negative impacts to human health and the environment. Therefore, it is important to understand the possibility of hazardous elements leaching. Aqueous batch leaching experiments under ambient conditions were conducted using six coal samples and their ash. Most of the coal leached very low concentrations of hazardous elements. However, an absence of carbonate minerals gave rise to higher acidity levels. This resulted in elevated leaching concentrations of manganese and iron, regardless of their contents. Burning coal resulted in higher contents of hazardous elements in the ash. However, leaching concentrations of most of the elements from the ash samples were still lower than the environmental standards. Chromium and manganese were enriched in slightly acidic leachates regardless of their contents while higher arsenic than the permitted level was leached from the ash containing the highest arsenic content that generated neutral pH leachate. These findings highlight a possibility of hazardous elements contamination from Mozambican coal and coal ash. Therefore, the storage of coal and disposal of coal wastes and ash in Tete Province should be done carefully and monitored to avoid the contamination in the region.

Impacts of Coal Use on Health.

This article reviews evidence for the public health impacts of coal across the extraction, processing, use, and waste disposal continuum. Surface coal mining and processing impose public health risks on residential communities through air and water pollution. Burning coal in power plants emits more nitrogen oxides, sulfur dioxide, particulate matter, and heavy metals per unit of energy than any other fuel source and impairs global public health. Coal ash disposal exposes communities to heavy metals and particulate matter waste. Use of coal in domestic households causes public health harm concentrated in developing nations. Across the coal continuum, adverse impacts are disproportionately felt by persons of poor socioeconomic status, contributing to health inequities. Despite efforts to develop renewable energy sources, coal use has not declined on a global scale. Concentrated efforts to eliminate coal as an energy source are imperative to improve public health and avert serious climate change consequences.

Respiratory Health in Adults Residing Near a Coal-Burning Power Plant with Coal Ash Storage Facilities: A Cross-Sectional Epidemiological Study.

Coal ash, the byproduct of burning coal made up of small particles, including heavy metals and radioactive elements, is discarded in open-air landfills where it can be emitted into the air, contributing to air pollution in the surrounding community. Few regulations exist regarding the storage, disposal, and transport of coal ash. There is limited research on the health impacts of coal ash exposure on communities. The purpose of this study was to examine the prevalence of respiratory symptoms among adults exposed to coal ash and non-exposed adults. A cross-sectional epidemiological study was conducted among two populations: one exposed to coal ash and one not exposed to coal ash. Perception of health (p-Value < 0.0001), cough (Adjusted Odds Ratio (AOR) = 5.30, 95% Confidence Intervals (CI) = 2.60–11), shortness of breath (AOR = 2.59, 95% CI = 1.56–4.31), hoarseness (AOR = 4.02, 95% CI = 2.45–6.60), respiratory infections (AOR = 1.82, 95% CI = 1.14–2.89), and mean overall respiratory health score (p-Value < 0.0001) were all statistically significantly greater in exposed adults (N = 231) when compared to non-exposed adults (N = 170). Adults residing near the coal ash facility were more likely to report respiratory symptoms than the non-exposed population. More research on the health impact of coal ash and storage regulations needs to be conducted.

Environmental radiological risk assessment of a coal ash and slag disposal site with the use of the ERICA Tool

The aim of this study was to assess the environmental radiological risk of coal ash and slag to terrestrial wildlife. The research site used in this study was a disposal site of coal ash and slag with enhaced content of uranium decay chain radionuclides. With the use of the ERICA Tool, total dose rates to wildlife and risk of resultant radiobiological effects were estimated. As input data for the assessment, experimental activity concentrations of 238U, 226Ra and 210Pb in coal ash and slag and best estimates of activity concentrations for related daughter radionuclides and 235U decay chain were used. Where possible, the experimental data for activity concentrations of 238U, 226Ra and 210Pb in plants and related concentration ratios were used. Results were compared to background dose rates, also estimated by the Tool. The Tool's assessment data indicated internal exposure as the prevalent exposure pathway with 226Ra and 210Po as the main dose contributors. Also, the contribution of 235U decay chain to the total dose rate was not negligible since for some organisms it represented up to 11% of the total dose rate. The risk of an occurrence of radiobiological effects in plants on the coal ash and slag disposal site can be considered negligible since the estimated total dose rates were below the screening dose of 10 μGyh−1 and near the dose rates estimated for plants in the control area. However, the estimated dose rates for reference animals and Lichen & Bryophytes were above the screening dose rate for most organisms and on average 13 times higher than the estimated background dose rates. At the given dose rates, an occurrence of different radiobiological effects could not be excluded for animals in close contact with coal ash and slag such as earthworms and small burrowing mammals. A separate assessment performed on an example of reference plants showed that the use of activity concentrations in organisms as input data can result in an order of magnitude smaller estimates of dose rates in comparison to activity concentration in coal and ash as input data. Our study highlighted the need for experimental data in radiological risk assessments to mitigate the conservatism of the ERICA Tool and its tendency to overestimate dose rates.

Feasibility of coal combustion fly ash alone and in combination with gypsum and green manure for reclamation of degraded sodic soils of the Indo‐Gangetic Plains: A mechanism evaluation

AbstractThe disposal of coal combustion fly ash (FA) generated from thermal power plants is a worldwide problem. However, its low bulk density and presence of calcium and iron–aluminium sesquioxide make it a prospective ameliorant alternative to gypsum for amending degraded sodic soils. A field experiment consisting of eight treatments with variable doses of FA and gypsum along with green manure (GM) was conducted for evaluating the amelioration mechanism by measuring changes in pH, exchangeable sodium percentage, zeta (ζ) potential, and properties of meso‐aggregates (0.5–2.0 mm). The results showed that compared with control, FA significantly reduced ζ‐potential, bulk density, and pH. The GM with FA further decreased ζ‐potential and increased hydraulic conductivity. The hydrolysis of iron and aluminium sesquioxide, present in FA, functioned to lower soil pH, whereas the reduction in exchangeable sodium percentage is attributed to bioavailable Ca (27.4%). A lower FA application rate produced better crop yields. FA 2.5% (w/w) alone, compared to the FA 5% (w/w), resulted in higher yield of rice (1.96 tonnes ha−1), whereas 25% gypsum requirement (25GR) + FA 2.5% (w/w) and 25GR + FA 2.5% (w/w) + GM provided wheat yield on par with 50% gypsum requirement (50GR). The study identifies that where gypsum is scarce, the recommended amendment is 25GR + FA 2.5% or 25GR + FA 2.5% + GM when applied for sodic soil to achieve a similar yield response to standard 50GR. If gypsum is unavailable, a one‐time application of FA 2.5% (w/w) alone will improve the productivity of degraded sodic soils corresponding to more exchangeable calcium and organic carbon, which were found to be higher for meso‐aggregates (0.5–2.0 mm).

Safe disposal of coal bottom ash by solidification and stabilization techniques

Solidification and stabilization of coal bottom ash waste (CBA) using CEM1 as the binder have been evaluated in case of leaching as well as the possibility to use this mixture for the construction industry. For this, the CEM1/CBA mass ratio has been varied between 0.5 and 2 and heavy metals leaching of Cu, Cd, Ni and Pb evaluated. Two types of crushed block and whole block leaching tests have been conducted to determine the leaching properties of deionized water, acetic acid and nitric acid leachates. It has been demonstrated that all elements can be immobilized successfully to nearly zero even in the case of a low CEM1 content. Furthermore, it has been shown that more heavy metals leached from the matrix when acetic acid used compared to other leachates. Next to this, the mechanical properties have been tested. After 56 days a compressive strength between 25 and 40 MPa has been measured from 0.5 to 2 CEM1/CBA mass ratios. Based on leaching and compressive strength results, CEM1/CBA mixtures can be considered for the construction industry.

United States Congressmen support the legalization of environmental health injustice in Puerto Rico.

Analyze the role of two members of the United States Congress, two private enterprises, and the government of Puerto Rico in the approval of the counterproductive law "Ban on the Deposit and Disposal of Coal Ash or Coal Combustion Residuals in Puerto Rico" (Law No. 40) in the framework of the four principles for environmental policy making. The gathered text documents were structured, reviewed, and coded using a content analysis protocol to produce coding categories and the final analysis. Two US congressmen, apparently influenced by private enterprises, had a decisive role in the approval of Law No. 40 which failed to comply with any of the four principles for environmental public policy making. Puerto Rico's Government succumbed to the extortion strategy of two US congressmen and private economic interests, and finally approved Law No. 40 which mistreats the general public and the environmental health of two low socioeconomic status communities in the municipalities of Guayama and Peñuelas. This law has the potential to negatively affect public health and the environment island-wide.