Elements In Ash Research Articles

Chemical Speciation, Leaching Behavior, and Environmental Risk Assessment of Trace Elements in the Bottom Ash from Biomass Power Plant.

Biomass combustion for power generation stands as a pivotal method in energy utilization, offering a promising approach for renewable energy utilization. However, the substantial volume of slag produced by biomass burning plants poses environmental challenges, impeding sustainable energy practices. This article systematically studies the characteristics of ash generated from typical biomass direct combustion power plant ash and analyzes the chemical composition, trace element content characteristics, leaching characteristics, and chemical forms of biomass bottom ash. Furthermore, it assesses the environmental ecology and bioavailability of trace elements in bottom ash using the ecological risk assessment method and RAC method. The results demonstrate that the biomass bottom ash contains plant nutrients, such as K, Ca, Mg, and P, while the content of harmful trace elements is lower than the relevant Chinese standards. In dissolution experiments, the leaching rate of nearly all elements remains exceptionally low, primarily due to the distribution of trace elements within the lattice structure of stable minerals. Trace elements predominantly exist in the residual phase, Cu and Zn primarily found in organic compounds and sulfide bound states, while other elements mostly exist in the form of iron manganese oxide bound states. Ecological risk assessment indicates a significant risk level for Cd, contrasting with the slight risk associated with other elements. RAC results indicated no ecological risk of all of the trace elements. Consequently, the utilization of bottom ash in agricultural and forestry soils is deemed to be viable. These findings serve as a crucial foundation for biomass bottom ash resource utilization and underpin the sustainable utilization of biomass energy.

Elemental composition and mineralogical characteristics of volcanic ash and soil affected by the eruption of Mount Semeru, East Java

Elemental composition and mineralogical characteristics of volcanic ash and soil affected by the eruption of Mount Semeru, East Java

HIGHLY EFFICIENT ONION PEEL ASH CATALYST FOR DEGRADATION OF METHYLENE BLUE

Methylene blue is a dye commonly used by the textile industry. However, its presence in textile effluent poses significant risks to human health and water resources. Various environmental technologies have been developed to remove this refractory pollutant from contaminated effluent. However, those techniques have limitations, such as high operational costs and use of unsustainable resources. In this study, the efficacy of an ash catalyst derived from household waste, namely onion peel waste, for degrading methylene blue was evaluated. Inductively coupled plasma-optical emission spectroscopy analysis revealed the presence of magnesium oxide, MgO, (528.00 ± 40.00 ppb) as one of the primary elements in onion peel ash, crucial for methylene blue degradation. Additionally, Fourier-transform infrared spectroscopy analysis identified an absorption band at around 871 cm-1, indicating the presence of MgO in the onion peel ash. The findings revealed that onion peel ash degraded methylene blue with an 84% (0.00616 min−1) degradation rate under sunlight and a 95% (0.00578 min−1) degradation rate under UV-lamp exposure. This research suggests that onion peel ash holds promise for effectively degrading methylene blue in textile effluents, offering a sustainable solution for addressing environmental concerns associated with textile dye pollution.

Rice straw ash and amphibian health: A deep dive into microbiota changes and potential ecological consequences

Rice straw is burned as a result of agricultural practices and technical limitations, generating significant volumes of ash that might have environmental and ecological consequences; however, the effects on organisms have not been researched. Amphibians depend on their gut and skin microbiomes. Ash exposure may cause inflammation and changes in microbial diversity and function in frogs' skin and gut microbiota due to its chemical composition and physical presence, but the implications remain unclear. Rana dybowskii were exposed to five aqueous extracts of ashes (AEA) concentrations for 30 days to study survival, metal concentrations, and microbial diversity, analyzing the microbiota of the cutaneous and gut microbiota using Illumina sequencing. Dominant elements in ash: K > Ca > Mg > Na > Al > Fe. In AEA, K > Na > Ca > Mg > As > Cu. Increased AEA concentrations significantly reduced frog survival. Skin microbiota alpha diversity varied significantly among all treatment groups, but not gut microbiota. Skin microbiota differed significantly across treatments via Bray-Curtis and weighted UniFrac; gut microbiota was only affected by Bray-Curtis. Skin microbiota varied significantly with AEA levels in Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes, while the gut microbiota's dominant phyla, Firmicutes, Bacteroidetes, and Proteobacteria, remained consistent across all groups. Lastly, the functional prediction showed that the skin microbiota had big differences in how it worked and looked, which were linked to different health and environmental adaptation pathways. The gut microbiota, on the other hand, had smaller differences. In conclusion, AEA exposure affects R. dybowskii survival and skin microbiota diversity, indicating potential health and ecological impacts, with less effect on gut microbiota.

Study on the spectra of Tieguanyin tea and ash by laser-induced breakdown spectroscopy

Tea ash is the inorganic residue of tea after a series of chemical and physical reactions under high temperature environment. The compositions of tea and ash are very different. In addition, the compositions of ash are closely related to the quality of tea. In this work, the compositions of Tieguanyin tea and ash were analyzed by laser-induced breakdown spectroscopy (LIBS), and the differences of elements in tea and ash were analyzed qualitatively. Tea contains the main elements, such as Ca, Na, Mg, and K, trace elements Fe, Cu, Zn, Mn and Sr, and other metallic elements Al, Li and Ba. Comparing the atomic and ionic lines in LIBS spectra of tea and ash, it was found that the spectral line intensities of metallic elements, i.e. Ca, Al, Mn, Mg, K, Na, Li, in the ash were significantly enhanced. In addition, there were CN, C2 and CaO molecular lines in the LIBS spectra of tea, but only CaO free radical was detected in the LIBS spectra of ash. The reason of the differences between the molecular lines of LIBS spectra of tea and ash was analyzed. This work is to determine the material compositions of tea and ash, which provides a basic foundation for the quality judgment of tea and a new idea for the enrichment detection of metallic elements.

Speciation distributions and risk assessments of trace elements in sludge and coal co-combustion ash

The co-combustion of sludge and coal has advantages such as utilizing the energy in sludge and reducing the treatment difficulty of sludge ash. Due to a wide source of sewage, the distributions of trace elements in co-combustion ash may differ from coal ash. Under laboratory conditions, the study examined the speciation distribution by the BCR method and evaluated the environmental risks and health risks of six typical trace elements in the co-combustion ash of sludge and coal. There is a significant difference in trace elements between sludge ash and coal ash, the highest content of heavy metals in coal ash and sludge ash is chromium (141.4 mg/kg) and zinc (1455.4 mg/kg), respectively. Coal ash has a lower heavy metal content and effective fraction than sludge ash, and coal ash is more stable. Risk assessment code analysis shows that most elements in co-combustion ash are at the low risk level, and when the blending ratio reaches 50%, chromium is at the medium risk level. According to Nemerow pollution index, cadmium can cause pollution to the environment when pH < 7.5. The risk of heavy metals in co-combustion ash on human health is at the acceptable level.

Experimental study on metal removal characteristics of Zhundong coal to produce ultra-clean coal using acid-alkali method

The large-scale application of coal-based deash carbon materials has put forward growing requirements for the removal technology of ash within coal. Extensive research has demonstrated that the contents of ash and metal elements have a large influence on the performance of the coal-based electrodes made from ultra-clean coal. However, there is a lack of research on the ash and mental elemental removal characteristics of Zhundong coal. In the present study, one kind of Zhundong coal characterized by a comparatively low ash content, was utilized to examine the characteristics of ash and metals removal during the acid-alkali ash removal process. An inductively coupled plasma optical emission spectrometer (ICP-OES) was utilized to analyze the metal element concentrations in the solution during ash removal and the metal element contents within the coal samples. The removal characteristics of metal elements were further analyzed based on the detection results. The experimental results indicate significant improvements in the removal of ash and metals through acid-alkali multi-stage leaching. Under the specific experimental condition here, a two-stage acid-alkali ash removal process achieves coal with the lowest ash content of 1.6% and the removal of 98.0% of Fe, 95.2% of K, and 94.6% of Na, with the removal of Al reaching up to 40%. In addition, the Fe removed in the acid leaching step accounted for 95% of the total amount removed, and adding an acid pretreatment step based on acid-alkali leaching can remove 90.2% of Fe within coal. Both the acid leaching and alkali leaching steps exhibit a certain removal proportion for Al, K, and Na elements, which are closely related to the existing form of these elements within the coal. Iron-containing minerals are mostly acid soluble and distributed on the surface of coal particles. Potassium-containing minerals are mainly alkaline soluble, resulting in a removal rate of over 60% in the alkali leaching step of acid-alkali leaching combined with acid pretreatment. The low removal rate of Al (∼40%) is due to the wide variety of Al-containing minerals, such as kaolin, illite, and aluminates, which are less removed during the reaction with alkali due to temperature limitations. The present study can offer improved knowledge on mineral removal to obtain ultra-clean coal for utilization as function materials.

Upcycling MSWI fly ash into green binders via flue gas-enhanced wet carbonation

Municipal solid waste incineration (MSWI) fly ash is a type of hazardous waste generated from waste incineration plants. This study developed a novel approach that recycled MSWI fly ash into eco-friendly binders via flue gas-enhanced wet carbonation treatment. During various washing processes, potentially toxic elements (PTEs) in MSWI fly ash showed different leaching patterns and pH dependence. Results suggested that 30 min flue gas-enhanced washing (optimal pH = ∼10.5) was favourable for immobilization of PTEs as well as sequestration of CO2 (12 wt %). The 28-day compressive strength of the pastes with 30 wt % flue gas-washed MSWI fly ash reached 84.2 MPa, which was significantly higher than the control pastes. Most of the PTEs, chlorides were effectively stabilised and solidified in the matrix. Compared to the cement-based binder, the cost of an alternative binder with 30 wt % flue gas-washed MSWI fly ash was −229.6 USD/m3, and the carbon emissions could be reduced by 36.1 %. Therefore, recycling carbonated MSWI fly ash into green binders exhibits a huge potential to close the waste cycle and mitigate climate change.

Mineralogy and Geochemistry of High-Sulfur Coals from the M8 Coal Seam, Shihao Mine, Songzao Coalfield, Chongqing, Southwestern China

Mineral matter, including minerals and non-mineral elements, in coal is of great significance for geological evolution, high-value coal utilization, and environment protection. The minerals and elemental geochemistry of Late Permian coals from the M8 coal seam, Shihao mine, Songzao coalfield in Chongqing, were analyzed to evaluate the sediment source, sedimentary environment, hydrothermal fluids, and utilization prospects of critical metals. The average total sulfur (4.21%) was high in coals, which mainly exists in the forms of pyritic sulfur. Kaolinite, pyrite, calcite, quartz, illite and illite/smectite (I/S) mixed layers, and anatase predominated in coals, with trace amounts of chlorite, ankerite, and siderite. Epigenetic cell- and fracture-filling pyrite, veined calcite, and ankerite were related to hydrothermal fluids and/or pore water after the diagenesis stage. Compared to the world’s hard coals, As and Cd are enriched in the Shihao M8 coals, and Li, Cr, Co, Zr, Mo, Pb, and Tb are slightly enriched. These high contents of sulfophile elements may be related to seawater intrusion. The terrigenous clastics of the Shihao M8 coals originated from the felsic–intermediate rocks atop the Emeishan Large Igneous Provinces (ELIP) (Kangdian Upland), while the roof and floor samples were derived from Emeishan high-Ti basalt. Through the combination of sulfur contents and indicator parameters of Fe2O3 + CaO + MgO/SiO2 + Al2O3, Sr/Ba and Y/Ho, the depositional environment of peat swamp was found to be influenced by seawater. Although the critical elements in coal or coal ash did not reach the cut-off grade for beneficial recovery, the concentration of Li and Zr were high enough in coal ash.

Ecological and Health Risks Attributed to Rare Earth Elements in Coal Fly Ash.

The occurrence and distribution of yttrium and rare earth elements (REYs), along with major elements and heavy metal(loid)s (HMs) in coal fly ash (CFA) from five coal-fired power plants (CFPPs), were analyzed, and the REY-associated ecological and health risks were assessed. The individual REYs in CFA were abundant in the following order: Ce > La > Nd > Y > Pr > Gd > Sm > Dy > Er > Yb > Eu > Ho > Tb > Tm > Lu. The total REY content ranged from 135 to 362 mg/kg, averaging 302 mg/kg. The mean light-to-heavy REY ratio was 4.1, indicating prevalent light REY enrichment in CFA. Significantly positive correlations between the REYs suggested that they coexist and share similar origins in CFA. REYs were estimated to pose low to moderate ecological risks, with risk index (RI) values ranging from 66 to 245. The hazard index (HI) and target cancer risk (TCR) of REYs from CFA, estimated to be higher for children (HIc = 0.15, TCRc = 8.4 × 10-16) than for adults (HIa = 0.017, TCRa = 3.6 × 10-16), were well below the safety limits (HI = 1, TCR = 1.0 × 10-6). However, the danger to human health posed by HMs in the same CFA samples (HIc = 5.74, TCRc = 2.6 × 10-4, TCRa = 1.1 × 10-4) exceeded the safe thresholds (excl. HIa = 0.63). The mean RI and HI attributed to REYs in CFA were 14% and 2.6%, respectively, of the total risks that include HMs.

Tetrafluoroboric Acid Digestion for Accurate Determination of Rare Earth Elements in Coal and Fly Ash by ICP-MS Analysis

Coal and coal-related fly ash often contain rare earth elements (REEs) that have the potential to be utilized as valuable mineral resources. Accurately determining the REE content in coal and fly ash is crucial for resource evaluation. The conventional approach involves using hydrofluoric acid (HF) to dissolve silicates and release REEs, which, however, prolongs the digestion process due to the additional step of complexing fluoride ions (F−) with boric acid (H3BO3). Determining the correct amount of H3BO3 for neutralization can be challenging, and in some instances, the binding of fluoride ions with certain lanthanides (Lns) hampers the accurate determination of all 14 naturally occurring rare earth elements in a single digestion batch by inductively coupled plasma mass spectrometry (ICP-MS). In this study, we present an alternative method that achieves the accurate determination of all 14 naturally occurring REEs using tetrafluoroboric acid (HBF4) followed by ICP-MS analysis. This approach eliminates the need for an F− complexing step. We tested this method on certified REE reference materials, including NIST 1632e (coal) and NIST 1633c (fly ash), as well as the REE geological reference material USGS AGV-1 (andesite). Our results demonstrated excellent recovery rates (relative standard deviation, RSD &lt; ±10%), with a correlation coefficient (r2) exceeding 0.99. Using this method, we investigated the concentrations of all 14 REEs in coal and fly ash samples collected from various locations in the southwestern USA. This improved digestion technique streamlines the analysis process and enhances the accuracy of REE determination, facilitating a more comprehensive evaluation of REE-rich coal and fly ash deposits for resource exploration.

Oilseed flax and alfalfa as sources of nutrient elements in the Central region of non-chernozem zone of Russia

The article presents the results of research for the year 2022. The objects of the research were oilseed flax and alfalfa. Percentages of crude protein, fiber and ash elements were evaluated in the crops. The content of nutrient elements was estimated by infrared spectrometry. In flax the content of the studied elements in seeds was estimated, in alfalfa the content of nutrient elements in green mass after the second cutting was estimated. Among oilseed flax samples, the highest raw protein yield was provided by Raduga variety (3.40 c/ha), it also provided the highest ash element yield among flax samples (0.92 c/ha), and Nilin variety provided the highest fiber yield (2.24 c/ha). Among alfalfa samples, sample Taisia (152.15 c/ha and 154.44 c/ha, respectively) showed the highest values for raw protein and fiber collection, while sample Agnia (54.90 c/ha) was the leader in ash elements collection.

Бетегелі-лерха жусанды қауымдастықтағы (Artemisia lerchiana, Festuca valesiaca) өнімділік процесі

The article presents the results of the study in accordance with the internationally accepted biological program of productivity, intensity of productivity-destructive processes and biological cycle of nitrogen and ash elements in the plant-soil system in the community of common Fescue-Lerh Wormwood (Artemisia lechiana, Festuca valesiaca). The studied area is located in the northeastern part of the Ural plateau in the Shelek district of Western Kazakhstan in a slightly undulating temperate dry-steppe zone with a slope to the valley of the Elek River in the Konchubai gully with dark chestnut carbonate-saline soils. The communities in the studied area are very important in pasture and forage farming. But under the influence of recent anthropogenic factors, vegetation and soil cover in plant communities are undergoing changes, the diversity of plant species is decreasing, biological productivity is decreasing, the circulation of chemical elements is changing, and plants of forage importance are being replaced by weevils. The community of common Fescue-Lerh Wormwood is characterized by moderate desertification, moderate digression. This community has decreased to 70% of the species diversity, and plants of forage importance have declined and have been slowly replaced by plants that are poor in feed. As a result of the effective use of this community can be restored.

Oilseed flax as a forage crop

The article presents the results of research for the year 2022. The objects of the research were 6 varieties of oilseed flax. Percentages of raw protein, fiber, ash elements and raw fat were evaluated in the crops. The content of nutrient elements was estimated by infrared spectrometry. In flax the content of the studied elements in seeds was estimated. Among all varieties oilseed flax samples, the highest raw protein yield was provided by VNIIMK 620 PN variety (4.24 c/ha), it also provided the highest ash element yield among flax samples (0.62 c/ha), in addition, this variety is also provided the highest fiber yield (2.65 c/ha). Such high rates in this variety are associated with the highest yield (17.33 c/ha). Because if you look at the percentage of raw fat of all 6 varieties, then Fliz variety was the most oilseed (42.57%), and most proteinous was Svetlyachok variety (25.64%)

Study on the soil pollution condition around the domestic wastewater

The rapid development in the population of the earth, the increase in the level of consumption of people leads to an increase in the amount of household waste from year to year, which, in turn, increases the negative impact on the environment of their collection and storage areas, that is, household waste landfills. From these studies, the state of contamination of the soil as scattered around the municipal landfill, the sources factors affecting the contamination were described. The main purpose of the conducted research is to determine the level of pollution of the soil under the influence of household waste. The researches were conducted in the soil scattered around the Tashkent municipal waste dump, located in the Ohangaron district were of the Tashkent province. The results showed that in the chemical pollution of irrigated typical gray soils, the domestic landfill is considered the main pollutant source, and the level of pollution decreases from the distance of 1.2 km from the landfill, and into according to the soil layers, it decreases uniformly from the top to the bottom, starting from the 70 cm layer.The soil scattered around the landfill is contaminated with organic pollutants, ash elements and heavy metals and other pollutants, including the total amount of Cd 3.1 times, As 4.39 times, Sb 2.46 times compared to the permissible limit share. , W 4.6 times and other heavy metals increased to different degrees.

Tracing rare earth elements in oil shale ash

Tracing rare earth elements in oil shale ash

Transformation of peat deposits and carbon accumulation in post-pyrogenic raised bogs within the taiga zone of West Siberia

The aim of the study was to assess of the transformation of the hydrologic and physical properties of peat deposits and peat accumulation rates in the post-pyrogenic sites of drained fens in the taiga zone of West Siberia. Location and time of the study. Field studies were conducted in 2022 on the Bakchar fen (drained for forestry, seven plots) and Ust-Bakchar fen (drained for peat extraction, three plots) located in the Tomsk region. Methods. Peat sampling was carried out from two boreholes at each plot in the hollow and the hummock. The sampling increment was 5 cm; the total depth was 45–90 cm. Peat samples were taken at nine subsites by the envelope method on each plot in 0–30 cm layer by 10 cm increment for water content determination in laboratory. Laboratory study of peat characteristics was carried out using the following methods: water and ash content measurements (GOST 11306-2013, GOST 11306-2013), estimation of peat decomposition and humification degree, botanical composition (GOST 28245-89), as well as measuring peat bulk density. Carbon stocks in the upper layer of peat deposits was estimated using the values of peat ash content and density. Results. The peat deposit of the upper layers was formed mainly by sphagnum peat with Sphagnum fuscum plant residues predominating. The differences between hollows and hummocks in their peat properties were manifested to a depth of 5–15 cm from the surface of depressions. The burnout of the hollows led to the changes of all peat properties to a depth of 10–15 cm: the changes were more pronounced in ash content, which was 1.5–9 times higher in the 0–5 cm layer as compared with the unburned site. The changes in peat properties on positive relief forms, i.e. moss hummocks, was less evident in the upper 0–5 cm layer, but reached a greater depth of 30 cm. The change was revealed mainly as an increase in peat ash content due to the migration of ash elements from the surface of burnt hollows and as an increase in bulk density due to subsidence of moss hummocks with the died-off sphagnum moss. Although the average water content in postpyrogenic and unburned sites was the same, amounting to 90–91% in the 0–30 cm layer, some difference was observed between the microrelief forms. The post-pyrogenic site in the Bakchar fen was characterized by water content decrease in hollows and hummocks, the maximum values being observed at an altitude near the average surface. In the Ust-Bakchar fen, water content was found to decrease from hollows to hummocks. In the Bakchar fen, 30 years after the fire peat accumulation occurred only on positive microrelief forms, where the 35 cm thick layer formed after the fire. Taking into account the microrelief heterogeneity, carbon accumulation over the post-fire period was estimated as 1.9 kg C/m2 or 60 g C/m2 per year. Peat accumulation seemed much slower in the Ust-Bakchar fen and was apparently absent on most of the surface. The average rate was estimated as 7 g C/m2 per year. Conclusions. The study found fen hollows to be most prone to burnout. The consequences of the fire manifest themselves in the drying of the upper layer of the peat deposit, thus preventing intensive overgrowth by sphagnum mosses 6–8 years after the fire. At the drained for forestry site in the Bakchar fen, 30 years after the fire the peat accumulation rate on moss hummocks was comparable to the rate in the unburned areas.

Degradation of peat-forming plants at the first stages of decomposition in natural and post-pyrogenic peatlands of West Siberia

The aim of the study. Assessment of the phytomass stocks and decomposition rate of peat-forming plants’ residues in peat deposits of natural and post-pyrogenic peatlands at the initial stages of decomposition. Location and time of the study. The study was carried out in 2022 (May-September) at two oligotrophic bog sites: “Bakcharskoye” (field station “Vasyuganye”, IMCES SB RAS) and “Iksinskoye”, which are located in the north eastern spurs of the Great Vasyugan mire in the Bakcharsky and Shegarsky districts of the Tomsk region, Russia. Methods. The phytomass stocks were determined by the cutting method. The following fractions were separated: living phytomass (annual and perennial photosynthetic phytomass, i.e. green parts of grasses, shrubs leaves, mosses); perennial non-photosynthetic phytomass, i.e. shrubs stems, roots of grasses and shrubs; and dead phytomass (mortmass), i.e. litter, moss litter, standing dead phytomass. The decomposition rate of plant residues was determined by the method of litter bags placement in peat (Chamaedaphne calyculata, Sphagnum fuscum, Mixed sample consisting of 60% S. fuscum and 40% Ch. calyculata). In the initial and decomposed samples, the ash content was determined by the dry combustion method. The total carbon and nitrogen content, as well as the carbon and nitrogen isotopic composition, were determined using a DELTA V Advantage isotope ratio mass spectrometer. Results. This short-term study conducted during the growing season in conditions of undisturbed (Natural Ryam) and post-pyrogenic (Gar) phytocenoses showed that due to a significant amount of mortmass (2402 g/m2) Natural Ryam had organic matter stock exceeding that in the Gar by 1.7 times. On average, 59% of organic matter loss from the total losses during the growing season occurred in the first month. In both Gar and Natural Ryam conditions, minimal losses of organic matter were characteristic for Sphagnum fuscum (3.1 and 3.5% respectively). For the remaining samples the Gar conditions were more favorable for the degradation at the initial stages of decomposition. The Mixed sample occupied an intermediate position between its individual components in terms of mass losses. Carbon losses correlated well with mass losses both over 1 month of degradation (r=0.87) and over 4 months (r=0.96). In contrast to carbon, nitrogen accumulated in the Mixed sample at the initial stages of degradation, both after 1 month and 4 months. Conclusions. With smaller phytomass stocks in areas of post-pyrogenic succession, more active decay at the initial stages of organic matter decomposition occurs exactly under these conditions. The impact of post-pyrogenic succession on the rate of organic matter decomposition of Chamaedaphne calyculata plant residues and the Mixed sample was demonstrated. The most intensive decomposition of litter occured during the first month of degradation. Additionally, in the conditions of a burnt bog, a more intense release of nitrogen from all plant residues and accumulation of ash elements in Sphagnum fuscum samples were observed. The mixing of litter components influenced both the rate and dynamics of decomposition. The carbon and nitrogen isotopic composition began to change during the initial stages of decomposition, leading to enrichment with heavier isotopes 15N and 13C. This research emphasizes the importance of studying the processes of plant litter decomposition at the initial stages and considering the plant residue composition when studying the processes of organic matter transformation.

Possible Options for Utilization of EU Biomass Waste: Pyrolysis Char, Calorific Value and Ash Content.

The application of biomass as a co-feed in coal power plants and in standalone biomass power plants, as well as in char production for soil remediation, is a currently important issue. This paper reports on the investigation of biochar formation from agricultural waste crops that are used for soil upgrading, but which do not meet the standards of EU crops, as well as largescale food processing waste. These were compared to test results from basket willow, which is commonly used for energy generation. Food industry waste is often produced in cities on a large scale and is generally easier to process due to lack of other stream components. The key parameters, namely, the content of volatiles, energy content of the formed biochar and the composition of the ash, were determined for a number of herbaceous materials locally available in the European Union. All of them can be used as a cheap source of biochar. A novel procedure of capturing volatiles and hence minimizing the PAH content in the biochar, as well as enabling the recovery of energy from the volatiles is presented. Knowledge of the composition and form of elements in ash is very important for designing ash management systems if co-combustion is implemented. The aim of this study was to determine if the types of biomass are better suited for biochar production or energy generation.

Concentration, speciation and risk effects of multiple environmentally sensitive trace elements in respirable fine-grained fly ash

Respirable fine-grained fly ash (RFA) is captured very inefficiently by existing air purification devices of power plant, leading to increasing concerns regarding their migration and subsequent interaction with body due to fine particle size and its complex toxic composition. Trace elements of RFA in three groups with five different sizes between 8–13 µm were analyzed in terms of available concentration, speciation and risk effects. The concentration, pollution level and ecological risk level of elements in RFA were related to particle sizes. Chronic non-carcinogenic effect risk (NER) and carcinogenic effect risk (CER) were negatively correlated with particle size. The individual weight of exposed subjects, corresponding trace elements concentration and ingestion rate in RFA were three significant variables influencing CER. NER and CER had a tenfold exaggerated effect when calculated using total element concentration of RFA. In addition to individual differences and exposure conditions, trace element properties, speciation and available concentration were the dominant factor responsible for ecological and environmental effects of trace elements in RFA, following the order As>Ni, Mn>Cr>Pb>Cu>Zn. Results of this work highlight the effects and differences of trace elements in RFA on ecology and health, and provide a basis for further pollution control and human health warning.