Life cycle assessment of alternative pulp mill sludge treatment methods in Finland.

Proper management of wastewater treatment plant side streams in pulp and paper mills is a matter of great interest. This study evaluates the environmental impact of different strategies in the management of biosludge from pulp and paper mills in Finland through a Life Cycle Assessment methodology. The base industrial standard practice, biosludge incineration for energy recovery and ash landfill disposal (Scenario 1), was compared to the alternative process of hydrothermal carbonization. The hydrochar generated from hydrothermal carbonization was evaluated for energy recovery through incineration (Scenario 2), or for use in composting for nutrient recovery (Scenario 3). The results showed that the hydrothermal process improved the overall environmental performance of the sludge management, particularly in terms of energy consumption and greenhouse gas emissions. The use of hydrochar as a soil amendment in composting also resulted in a significant reduction on the environmental impact compared to the other two scenarios. Overall, this study highlights the potential of hydrothermal carbonization and hydrochar utilization as sustainable options for managing biosludge from pulp mills.

A study of the stabilization and solidification of heavy metals in co-vitrification of medical waste incineration ash and coal fly ash.

Medical waste incineration ash (MWIA) has significant concentrations of heavy metals, dioxins, and chlorine that, if handled incorrectly, might cause permanent damage to the environment and humans. The low content of calcium (Ca), silicon (Si), and aluminum (Al) is a brand-new challenge for the melting technique of MWIA. This work added coal fly ash (CFA) to explore the effect of melting on the detoxication treatment of MWIA. It was found that the produced vitrification product has a high vitreous content (98.61%) and a low potential ecological risk, with an initial ash solidification rate of 67.38%. By quantitatively assessing the morphological distribution features of heavy metals in ashes before melting and molten products, the stabilization and solidification rules of heavy metals during the melting process were investigated. This work ascertained the feasibility of co-vitrification of MWIA and CFA. In addition, the high-temperature melting and vitrification accelerated the detoxification of MWIA and the solidification of heavy metals.

Evolving waste management: The impact of environmental technology, taxes, and carbon emissions on incineration in EU countries.

Amid the urgent global imperatives concerning climate change and resource preservation, our research delves into the critical domains of waste management and environmental sustainability within the European Union (EU), collecting data from 1990 to 2022. The Method of Moments Quantile Regression (MMQR) results reveal a resounding commitment among EU member states to diminish their reliance on incineration, which is evident through adopting green technologies and environmentally conscious taxation policies, aligning with the European Union's sustainability objectives. However, this transition presents the intricate task of harmonizing industrial emissions management with efficient waste disposal. Tailoring waste management strategies to accommodate diverse consumption patterns and unique circumstances within individual member states becomes imperative. Cointegrating regressions highlighted the long-run relationship among the selected variables, while Feasible Generalized Least Squares (FGLS) and Panel-Corrected Standard Errors (PCSE) estimates roughly confirmed MMQR results. ML analyses, conducted through two ensemble methods (Gradient Boosting, GB, and Extreme Gradient Boosting, XGBoost) shed light on the relative importance of the predictors: in particular, environmental taxation, consumption-based emissions, and production-based emissions greatly contribute to determining the variation of combustible renewables and waste. This study recommends that EU countries establish monitoring mechanisms to advance waste management and environmental sustainability through green technology adoption, enhance environmental taxation policies, and accelerate the renewable energy transition.

Evolution of physicochemical and leaching characteristics of municipal solid waste incineration fly ash in China under ultra-low emission standard.

The physical and chemical characteristics of fly ash has changed significantly under ultra-low emission system and the current leaching system is no longer suitable for high alkalinity fly ash. This work investigated the pH values and evolution of physical and chemical characteristics of fly ash from 24 typical municipal solid waste incineration plants in China. The pH value of the leaching solution obtained by HJ/T 300-2007 presented two different acid and alkali characteristics, where high and low alkalinity fly ash accounted for 54.17% and 45.83%, respectively. The alkali content in fly ash increased significantly after ultra-low emission standard, increasing by 18.24% compared with before the implementation of GB 18485-2014. The leaching behavior of high alkalinity fly ash showed the illusion that they could enter the landfill only by the addition of a small amount of chelating agent or even without stabilization treatment, and its long-term landfill risk is significant. The phase change of high alkalinity fly ash and pH value change of the leaching solution after carbonation were the key factors for the leaching concentration change of heavy metals. Therefore, it is recommended to improve the existing leaching system or conduct accelerated carbonization experiments to scientifically evaluate the long-term leaching characteristics of high alkalinity fly ash, and to reduce the risk of heavy metal release from high alkalinity FA after entering the landfill site.

Hydrothermally Stimulated Molecular Interfaces for Augmented Electron Delocalization in Wet-Chemical Phosphorus Recovery from Incineration Ash of Sewage Sludge.

Wet-chemically recovering phosphorus (P) from sewage sludge incineration ash (SSIA) has already become a global initiative to address P deficit, but effectively isolating P from these accompanying metals (AMs) through adsorption in a SSIA-derived extract remains elusive. Here, we devised a hydrothermal stimulus-motivated thermodynamic and kinetic enhancement to gain anionic ethylenediaminetetraacetic acid (EDTA) molecular interfaces for AM enclosure to resolve this conundrum. A new dosage rule based on the EDTA coordination ratio with AMs was established for the first time. Upon hydrothermal extraction at 140 °C for 1 h, the P extraction efficiency reached 96.7% or higher for these obtained SSIA samples, and then exceptional P sequestration from these EDTA-chelated AMs was realized by the peculiar lanthanum (La)-based nanoadsorbent (having 188.86 mg P/g adsorbent at pH ∼ 3.0). Relevant theoretical calculations unraveled that these delocalized electrons of tetravalent EDTA molecules boosted the enclosure of liberated AMs, thereby entailing a substantially increased negative adsorption energy (-408.7 kcal/mol) of P in the form of H2PO4- through intruding lattice-edged carbonates to coordinate La with monodentate mononuclear over LaCO5(1 0 1). This work highlights the prospect of molecular adaptation of these common extractants in wet-chemical P recovery from various P-included wastes, further sustaining global P circularity.

Characterization and spatiotemporal variations of fluorescent dissolved organic matter in leachate from old landfill-derived incineration residues and incombustible waste.

Dissolved organic matter (DOM) influences the bioavailability and behavior of trace metals and other pollutants in landfill leachate. This research characterized fluorescent dissolved organic matter (FDOM) in leachate from an old landfill in Japan during a 13-month investigation. We employed excitation-emission matrix (EEM) fluorescence spectroscopy with parallel factor analysis (PARAFAC) to deconvolute the FDOM complex mixture into three fluorophores: microbial humic-like (C1), terrestrial humic-like (C2), and tryptophan-like fluorophores (C3). These FDOM components were compared with findings from other studies of leachate in landfills with different waste compositions. The correlations among EEM-PARAFAC components, dissolved organic carbon (DOC) concentration, and ultraviolet-visible and fluorescence indices were evaluated. The FDOM in leachate varied spatially among old and extended leachate collected in the landfill and leachate treatment facility. The FDOM changed temporally and decreased markedly in August 2019, November 2019, and April 2020. The strong positive correlation between HIX and %C2 (r = 0.87, ρ = 0.91, p < 0.001)) implies that HIX may indicate the relative contribution of terrestrial humic-like components in landfill leachate. The Fmax of C1, C2, and C3 and the DOC concentration showed strong correlations among each other (r > 0.72, ρ > 0.78, p < 0.001) and positive correlations with leachate level (r > 0.41, p < 0.001), suggesting the importance of hydrological effects and leachate pump operation on FDOM.

Effect of separation pretreatment on environmental and economic performance of sludge resource utilization.

As a new technology for accurate utilization of sludge resources, sludge inorganic-organic matter separation (IOMS) has attracted wide attention. This study examined the impact of this pretreatment on environmental and economic performance of sludge composting and incineration using life cycle assessment (LCA) and whole life costing (WLC). LCA results indicated that IOMS pretreatment reduced the energy conservation and emission reduction (ECER) values of composting and incineration by 56 % and 76 %, respectively. Meanwhile, WLC exhibited that IOMS pretreatment could cut the break-even year of incineration from 11 years to 4 years. The combination of organic sludge incineration/composting with inorganic sludge sintering ceramsite reveals excellent environmental and economic performance. The application optimization hypothesis analysis of these two routes in various provinces of China indicates that Jiangsu has the greatest development potential and should become a major promotion region.

Comparative life cycle assessment of landfill sludge treatment technologies in China.

Reasonable treatment of large amounts of sludge excavated from landfills has gained increasing attention due to the diminishing availability of landfill space in China. In this study, five landfill sludge (LS) treatment technologies using life cycle assessment (LCA) and life cycle cost (LCC) were investigated, i.e., co-incineration in coal-fired power plants (CFPP) and waste incineration power plant (WIPP), co-processing in cement kiln, bricks production, and sintering ceramsite. The LCA results demonstrate that sintering ceramsite outperforms other technologies and LCC results indicate sintering ceramsite also provides the highest economic benefit ($869.94). To further enhance environmental and economic performances of the LS treatment, the substitution of coal with natural gas and biomass can reduce Energy Conservation and Emission Reduction (ECER) index by 74% and 98%, respectively. This substitution can increase economic returns by 24% and 26%, respectively. Furthermore, national-level economic benefit and carbon emission reduction potential of different LS treatment technology alternative scenarios were assessed. Results display that a combination of 50% CFPP, 25% bricks, and 25% ceramsite (biomass) offers the highest economic gain, which is 3.02 times that of 50% CFPP and 50% cement (original case). Conversely, the replacement of 25% brick with 25% cement in the above combination result in the lowest carbon reduction, which is 9.35 times that of the original case.

Strontium leaching from municipal waste subjected to incineration.

The aim of the study was to determine the content and leachability of Sr in ashes obtained through combusting municipal waste in household furnaces. The waste had been collected as a mixed stream and as separate fractions (i.e. furniture, sponges, waste paper, PCV packaging, plastic-coated paper cartons, imitation leather, rubber, textiles and polystyrene). Using single-step chemical extractions, (HCl + HNO3, H2O, 0.01 M CaCl2, 0.1 M CH3COOH), we determined the total content of Sr (TC) and proportions of the following fractions: water-leachable, phytoavailable and easily soluble and bound to carbonates. We also analyzed the effect of reducing pH in the extraction solutions on St leachability from the study material. The study showed that Sr concentration in ash generated from the combustion of conventional fuels, alternative fuels and municipal waste ranged from 114 to 1006 mg/kg. The largest amounts of Sr were found in ash generated from the combustion of alternative fuels (coal pellets 488-1006 mg/kg), conventional fuels (hard coal 430-670 mg/kg) and mixed waste (237-825 mg/kg). The most mobile fraction of Sr (water-leachable) comprised from 1.3% to nearly 91% TC; the phytoavailable fraction and the ion-exchange and carbonate-bound fraction comprised 3-92% TC and 9-72% TC, respectively. We also found that the greatest pH reductions do not always entail the greatest amounts of extracted Sr. A much more significant factor in this respect is the mineral and chemical composition of primary materials, which can buffer changes in pH. The Risk Assessment Code (RAC) values pointed to a varied environmental risk and the highest RAC values (> 70) were found for coal pellets, wood pellets, straw, rubber and plastic containers for mixed oils.

Gate-to-grave assessment of plastic from recycling to manufacturing of TENG: a comparison between India and Singapore.

This study assesses the viability of recycled plastic-based triboelectric nanogenerators (TENGs) for sustainable energy harvesting in India and Singapore, concurrently examining plastic waste management. Using material flow analysis and life cycle assessment, the findings revealed that in Singapore, waste-to-energy incineration has a lower environmental impact than landfilling and mechanical recycling, attributed to natural gas usage. In India, recycling offsets impacts from incineration and landfilling, contributing to a lower net environmental impact. Economic performance of a TENG module from PET recyclates showed a 20% carbon footprint reduction when scaling up from lab to industrial "freeze-drying" processes. Key challenges in TENG manufacturing processes are also assessed for future development. This research highlights the potential of recycled plastic-based TENGs in sustainable energy and waste management.

Chlorine-induced Gas-Solid coupled corrosion behaviors of tube materials in high steam parameter MSW incinerator.

The fast development of the waste incineration industry requires deeper insights into heating surface corrosion behavior at higher operating parameters with complex corrosion sources. This research investigates the corrosion behaviors of three types of plates, namely SA210-C, TP310, and 12CrMoV, when subjected to simulated flue gas and fly ash deposition simultaneously at temperatures ranging from 500℃ to 620℃. The results indicate that the weight loss due to coupling corrosion was 2.5 to 84.5 times higher than that of gas-phase corrosion under the same operating conditions. Among the three stainless-steels, TP310 demonstrates superior corrosion resistance. It is worth noting that, under the gas-solid coupling corrosion conditions, we observed a distinct two-layer structure of corrosion products. Despite the fly ash simulants detaching over time, the two-layer structure remained unchanged. Based on the theory of eutectic molten salt formation, we propose that alkali metal chlorides only initiate the formation of the molten layer in the initial stage of corrosion. Furthermore, we offer additional suggestions for the mechanism of sustaining the molten layer in the absence of alkali metal chlorides.

Impact of terephthalic acid emissions from intensive nocturnal biomass incineration on oxidative potential in Seoul, South Korea.

This study investigated the impact of large-scale incineration facilities on PM2.5 levels in Seoul during winter. Due to the challenge of obtaining accurate combustion data from external sources, heat supply records were used as a proxy for combustion activity. To assess health risks, dithiothreitol-oxidative potential (DTT-OP) was analyzed to identify potential hazards to human health. By comparing DTT-OP with PM2.5 sources related to combustion, the study aimed to understand the impact of local pollution sources on human health in Seoul. The diurnal analysis showed that oxidative potential (0.19 µM/m3) and the biomass burning factor (5.53 µg/m3) peaked between 4:00 and 8:00 AM, with lower levels observed from 12:00 to 20:00. A significant correlation was found between combustion sources and oxidative potential, with a high correlation coefficient (r2 = 0.92). The presence of terephthalic acid (TPA) in the Cellulose combustion source profile, which is produced by the pyrolysis of plastics like polyester fiber and polyethylene terephthalate (PET), further supported the link to emissions from incineration facilities. These findings suggest that the biomass burning source is strongly correlated with DTT-OP, indicating a significant association with health risks among various local sources of PM2.5 in Seoul.

Reduction of heavy metals in municipal solid waste incineration fly ash followed by making transparent glass.

Municipal solid waste incineration (MSWI) fly ash is a hazardous waste containing heavy metals. Secondary aluminum dross (SAD) is a hazardous waste discharged from aluminum smelting, containing active aluminum nitride (AlN). In this work, heavy metals from MSWI fly ash were reduced into alloy by AlN from SAD, and the slag was manufactured into transparent glass for building. Reduction of iron and zinc was 67 and 100 %, respectively. Reduction mechanism was explored after applying XRD, XRF and thermodynamics analysis. It was found that the reduction reaction was an ion reaction. The AlN and heavy metal oxide transformed into anionic group containing nitrogen and heavy metal cation, after entering slag. The heavy metals were reduced into alloy after electron was transferred from anionic group to cation. In addition, the reduced iron and zinc could merge into alloy, which inhibited evaporation of zinc. Yellow transparent glass was obtained after the reduction process. Yellow was come from titanium oxide, which could not be reduced by AlN. Microhardness, density and water absorption of the transparent glass were 741 HV, 2.86 g·cm-3 and 0.04 %, respectively. Leaching content of Ni, Cu, Zn and Pb of the glass were 0.1, <0.1, 0.6 and < 0.1 mg/L, respectively, all below the TCLP limit. About 115 âˆ¼ 213 dollars were earned after manufacturing 500 kg of MSWI fly ash into transparent glass. This work provided a novel idea of recycling solid waste into alloy and transparent glass for building.

High temperature melting of municipal solid waste incineration (MSWI) fly ash and co-disposal technology with blast furnaces.

With the development of municipal solid waste incineration technologies, the disposal of fly ash has become a difficult problem that many countries need to solve. High-temperature melting is a promising disposal technology. Based on this, a new process for collaborative treatment of fly ash in metallurgical blast furnaces had been proposed in this study. To explore the impact of disposal of fly ash on blast furnace production, by simulating the high-temperature reducing environment of blast furnaces, the melting changes of water-washed fly ash (W-FA), and the effects of W-FA injection on coal combustion and products (slag, iron) composition were studied. The results showed that W-FA, as a flux, could be sprayed into the blast furnace separately or mixed with coal. But when injected along with coal, W-FA would suppress the combustion of coal. After melting, the removal rates of S, P, Cl, and Pb in W-FA were 21%, 30%, 86%, and 89%, respectively. The removal rates of K, Na, and Zn were close to 100%, and Cr was basically not removed. When the proportion of W-FA to coal was less than 1%, in addition to controlling the alkalinity of the slag, the impact of W-FA on the composition of iron and slag was minimal. The successful execution of this work will not only achieve the reduction, harmless and resourceful utilization of fly ash, but also save investment and operating costs of disposal facilities, with both environmental and social benefits.

Incineration-source fingerprints and emission spectrums of dioxins with diagnostic application.

Despite increasing waste-to-energy (WtE) capacities, there remain deficiencies in comprehension of 136 kinds of tetra- through octa-chlorinated dibenzo-p-dioxin and dibenzofurans (136 PCDD/Fs) originating from incineration sources. Samples from twenty typical WtE plants, encompassing coal-fired power plants (CPP), grate incinerators (GI), fluidized bed incinerators (FBI), and rotary kilns (RK), yielded extensive PCDD/F datasets. Research was conducted on fingerprint mapping, formation pathways, emission profiles, and diagnostic analysis of PCDD/Fs in WtE plants. Fingerprints revealed a prevalence of TCDF, followed by PeCDF, while CPP and RK respectively generated more PCDD and HxCDD. De novo synthesis was the predominant formation pathway except one plant, where CP-route dominated. DD/DF chlorination also facilitated PCDD/F formation, showing general trends of FBI > GI > CPP > RK. The PCDD/F emission intensities emitted in air pollution control system inlet (APCSI) and outlet (APCSO) followed the statistical sequence of RK > FBI > GI > CPP, with the average I-TEQ concentrations in APCSO reaching 0.18, 0.08, 0.11, and 0.04 ng I-TEQ·Nm-3. Emission spectrum were accordingly formed. Four clusters were segmented for diagnosis analysis, where PCDD/Fs in GI and FBI were similar, grouped as a single cluster. PCDD/Fs in CPP and RK demonstrated distinctive features in TCDD, HxCDD, and HxCDF. The WtE plants exceeding the limit value tended to generate and retain fewer TCDD and TCDF yet had higher fractions of HxCDD and HxCDF. The failure of APCS coupled with the intrinsic source strength of PCDD/Fs directly led to exceedance, highlighting safe operational practices. This study motivated source tracing and precise evaluation of 136 PCDD/Fs based on the revealed fingerprint profiles for WtE processes.

Co-pyrolysis of fly ash with sewage sludge for PCDD/F removal.

Fly ash generated from municipal waste incineration (MWI) contains various toxic substances, and it has to be properly treated before disposal or reuse. Water washing and thermal pyrolysis can improve the destruction efficiency of PCDD/Fs in fly ash generated from municipal solid waste incinerators. Since sulfur oxides and nitrogen compounds generated by the heating of the sewage sludge poison the catalytic active sites for PCDD/Fs formation on fly ash surface, co-pyrolysis of fly ash with sewage sludge effectively inhibits precursor formation and de novo synthesis reaction, resulting in the great reduction of PCDD/F formation. The results of the pyrolysis at 350 °C show that the PCDD/Fs removal efficiencies based on mass concentration are over 99%. The results at 350 °C of different reaction times show that the reaction time of 10 min is sufficient to reach the European End of Waste criteria (≤ 20 pg TEQ/g) when the ratio of fly ash/sewage sludge is controlled at 1:1.

Environmental and economic analysis of the transformation of paper mill sludge treatment technologies in China.

Paper mill sludge (PMS) is featured with a high content of cellulose and hemicellulose, and using its characteristics to make paperboard can achieve a high-value utilization of PMS, which has attracted growing interest. In this study, currently prevalent landfill, incineration technologies (generating heat and electricity by incineration), and three paperboard technologies (medium density fiberboard, pulp board, and corrugated paper) were evaluated and compared via life cycle assessment (LCA) and life cycle costing (LCC) methods. LCA results show that the PMS-to-pulp board outperforms others with an energy conservation and emission reduction (ECER) value of - 2.86 × 10-8, while the landfill exhibits the highest overall environmental impact with an ECER value of 4.80 × 10-9. LCC results reveal that the PMS-to-pulp board delivers the highest economic profit with $257.357, while the landfill is the lowest with $ - 35.63. The PMS paperboard technologies are more economically friendly than the incineration technologies due to additional electricity/steam consumption during the PMS pre-drying process in incineration. In addition, different scenarios were set up to explore national GHG emission reduction potential by increasing paperboard technologies application rate and reducing the proportion of landfill and incineration. The scenario analysis suggests that replacing 90% of landfill and incineration ratio with PMS paperboard technologies could tremendously improve the overall emission reduction performance with - 9.08 × 1010 kg CO2 eq. This result indicates that the PMS treatment technology transformation has a significant favorable impact on the achievement of the "carbon neutrality" target.

Complementary vitrification of municipal solid waste incineration fly ash from grate furnaces and fluidised bed incinerators via a co-reduction process.

The increasing application of municipal solid waste incineration (MSWI) emphasises the need for MSWI fly ash (FA) safe treatment. Based on the compositional complementarity of FA from grate furnaces (G-FA) and fluidised bed incinerators (F-FA), we proposed a co-reduction process to treat G-FA and F-FA together for producing vitrified slag and ferroalloys. The clean vitrified slag and Fe-Cr-Ni-Cu alloy were obtained with the mass ratios of 1:9 âˆ¼ 6:4 (G-FA:F-FA) at 1300℃, which is about 300℃ lower than the conventional G-FA vitrification. The metals Zn, Cd, and Pb were mostly volatilised into the flue gas for potential recovery from the secondary FA. The thermodynamic SiO2-Al2O3-CaO ternary system demonstrated that an optimal mass ratio of the two complementary FA types contributes to the system shifting to the low-temperature melting zone. The co-reduction process of G-FA and F-FA could be a promising option for FA beneficial reutilization with environmental advantages.

Life cycle assessment of plastic waste in Suzhou, China: Management strategies toward sustainable express delivery.

The explosive growth of China's express delivery industry has greatly increased plastic waste, with low-value plastics not effectively utilized, such as PE packaging bags, which are often not recycled and end up in landfills or incinerators, causing significant resource waste and severe plastic pollution. A gate -to- grave life cycle assessment was adopted to assess the impacts of express delivery plastic waste (EDPW) management models (S1, landfill; S2, incineration; S3, mechanical pelletization), with Suzhou, China as a case. Results showed that mechanical pelletization, was the most environmentally advantageous, exhibiting a comprehensive environmental impact potential of -215.54 Pt, significantly lower than that of landfill (S1, 78.45 Pt) and incineration (S2, -121.77 Pt). The analysis identified that the end-of-life disposal and sorting stages were the principal contributors to environmental impacts in all three models, with transportation and transfer stages of residual waste having minimal effects. In terms of all environmental impact categories, human carcinogenic toxicity (HTc) emerged as the most significant contributor in all three scenarios. Specifically, S1 exhibited the most detrimental effect on human health, while S2 and S3 showed positive environmental impacts. Based on these findings, it is recommended that the application and innovation in mechanical recycling technologies be enhanced, the promotion of the eco-friendly transformation of packaging materials be pursued, and a sustainable express delivery packaging recycling management system be established. These strategies are essential for achieving more eco-friendly management of EDPW, reducing its environmental pollution, and moving towards more sustainable express delivery management practices.

Migration of trace elements and radioisotopes to various fractions of solid wastes generated as a result of the sewage sludge incineration process.

The research was aimed at providing new knowledge in the field of chemical characteristics of solid waste generated in the process of combustion of sewage sludge in fluidized bed furnaces. The research material consisted of disposed fluidized beds (DFB), sewage sludge ash (SSA) and air pollution control residues (APC) from three Polish installations for the thermal treatment of sewage sludge. Natural radionuclides as well as anthropogenic isotope 137Cs were determined in the tested materials and the migration of a wide spectrum of trace elements to various waste fractions generated in the process of sewage sludge combustion was examined. It was observed that both radioisotopes and most of the trace elements determined accumulate in SSA and DFB, while the APC fraction contains a much smaller amount of them. The exceptions are mercury and selenium, whose volatile compounds migrate to the exhaust gas dedusting system and accumulate in the APC fraction (up to 40 mg/kg and 13 mg/kg, respectively). A potential threat from the 226Ra isotope in SSA is identified in the context of the management of this waste in the production of building materials because the typical activity of 226Ra in SSA collected from areas with very low Ra content in natural environment exceeds 1.5-6 times the activity of this isotope in conventional cement mixtures. When managing SSA and DFB, special attention should be paid to the content of metalloids such as As, B and Se, due to the high content of mobile forms of these elements in the mentioned materials.