Solid Sediment Research Articles

Sediment Transport in Sewage Pressure Pipes, Part I: Continuous Determination of Settling and Erosion Characteristics by In-Situ TSS Monitoring Inside a Pressure Pipe in Northern Germany

Continuous measurement systems are widely spread in sewers, especially in non-pressure systems. Due to its relatively low costs, turbidity sensors are often used as a surrogate for other indicators (solids, heavy metals, organic compounds). However, little effort is spent to turbidity sensors in pressurized systems so far. This work presents the results of one year in-situ turbidity/total suspended solids (TSS) monitoring inside a pressure pipe (600 mm diameter) in an urban region in northern Germany. The high-resolution sensor data (5 s interval) are used for the determination of solids sedimentation (within pump pauses) and erosion behavior (within pump sequences). In-situ results from sensor measurements are similar to laboratory results presented in previous studies. TSS is decreasing exponentially in pump pauses under dry weather inflow with an average of 0.23 mg/(L s). During pump sequences, solids eroded completely at a bed shear stress of 0.5 N/m². Sedimentation and erosion behavior changes with the inflow rate. Solids settle faster with increasing inflow: at storm water inflow with an average of 0.9 mg/(L s) and at diurnal inflow variation up to 0.6 mg/(L s) at 12:00 a.m. The results are used as calibration data for a sediment transport simulation in Part II.

Self-attenuation corrections for radium measurements of oil and gas solids by gamma spectroscopy

Beneficial reuse and resource recovery of produced water often require treatment to remove radium before valuable products are extracted. The radium content of the treatment waste solids and beneficial products must be accurately determined when evaluating the efficacy and social validity of such treatments. While gamma spectroscopy remains the recommended method for radium measurements, these measurements can be impacted by the composition/mineralogy of the solids, which influence the attenuation of the gamma decay energy – with denser sediments incurring greater degrees of attenuation. This self-attenuation must be accounted for when accurately measuring radium, otherwise radium measurements are found to be inaccurate, sometimes by as much as 50%. To meet industry needs, measurements should be both accurate and rapid, even for small sample sizes. Consequently, we propose a rapid method for accurate radium measurements with an empirical technique to account for sample attenuation in well-detector gamma spectroscopy. This technique utilizes the sample density and sample volume in the measuring vial. These corrections are relevant to a wide range of solid samples and sediment densities that may be encountered during treatment and management of oil and gas solids, including clays, environmental sediment samples, sand grains, and precipitated salts. These corrections can also be applied for situations were low volumes of material are present, as in bench scale studies, thereby rendering this technique applicable to a wider range of scenarios.

Remoción de Calcio y Magnesio en Agua de Mar para Mejorar la Concentración de Sólidos en la Descarga de Espesadores

Seawater with reduced amounts of calcium and magnesium was used for increasing the concentration of sediment solids from a mine tailing. The assays were carried out considering a synthetic tailing, composed of quartz and kaolinite, and utilising an anionic flocculant of high molar weight. Seawater produced an efficient behaviour when working at pH < 9. However, at higher alkalinity the solid concentration of the sediment was substantially reduced. Isolating the effect of the main seawater ions it was found that magnesium, and to lesser extent calcium, are responsible for reducing the flocculation efficiency, caused by the formation of MgOH+ /CaOH+ complexes and Mg(OH)2 precipitates. For this reason, when using seawater with a reduced amount of calcium and magnesium, it was possible to considerably increase the solids content, offering an effective alternative to operate at highly alkaline conditions.

Effects of suspended sediment on POCIS sampling rates

Effects of chemical uptake onto polar organic chemical integrative samplers (POCIS) exposed to total suspended solid (TSS) sediment concentrations of 0 and 3600 ppm were investigated for 12 pesticides at constant concentration, temperature, and flow velocity. The effects of sediment exposure on POCIS uptake were negligible for compounds with polyethersulfone-water partition coefficients greater than three (i.e., log KPESW > 3). However, significant effects were observed for 3 of 12 compounds tested, and the maximum effect was an approximate 4-fold increase in sampling rate for the sediment experiment relative to the control. Effects of sediment on the pesticide distribution between polyethersulfone (PES) membranes and Oasis HLB sorbent were also investigated. The fraction of pesticide accumulated on PES membranes was relatively low for most compounds and ranged from 0 to 33%. In contrast, four compounds with higher affinity for PES accumulated preferentially on the membranes (fraction ranging from 64 to 96%), suggesting that a sampling rate derived from the additive contribution of membrane extraction and the more typical extraction of analytes from HLB sorbent would improve the sensitivity of sampling rate estimations for these compounds. However, for these same compounds, the combined sampling rate, Rs (HLB + PES), was considerably more susceptible to a sediment effect than the traditional sampling rate determination, relying solely on extraction from HLB sorbent.

ПОВЫШЕНИЕ ЭНЕРГЕТИЧЕСКОЙ И ЭКОЛОГИЧЕСКОЙ ЭФФЕКТИВНОСТИ СИСТЕМ ГАЗООЧИСТКИ НА ТЭС

Актуальность исследования обусловлена необходимостью повышения энергетической и экологической эффективности систем очистки выбросов систем пылеприготовления и дымовых газов ТЭС при угольной генерации и систем подготовки газа при газовой генерации, во исполнение Федерального закона № 261-ФЗ от 23.11.2009 г. (ред. от 29.07.2017) «Об энергосбережении и о повышении энергетической эффективности и о внесении изменений в отдельные законодательные акты Российской Федерации», а также требований по контролю за выбросом парниковых газов (напр., приказа № 330 от 29.06.2017 года «Об утверждении методических указаний по количественному определению объёма косвенных энергетических выбросов парниковых газов» и др.) выбросов систем пылеприготовления и дымовых газов ТЭС с угольной генерацией и в системе подготовки газа с газовой генерацией. Цель: разработка устройства циклонной фильтрации для повышения эффективности систем газоочистки на ТЭС, снижения выбросов взвешенных частиц в атмосферу от систем пылеприготовления и дымовых газов при угольной генерации и увеличения надежности работы агрегатов газотурбинных и парогазовых установок ТЭС вследствие снижения износа рабочих поверхностей поршневых и винтовых дожимающих компрессоров дожимных компрессорных станций, предотвращения попадания продуктов внутренней коррозии газопроводов в газотурбинных установках, в соответствии с п.п. 93, 94 ФНиП в области промышленной безопасности «Правила безопасности сетей газораспределения и газопотребления» (Серия 12, вып. 13). Объект: модель циклона на базе ЦН-11-200, обеспечивающая повышение энергетической и экологической эффективности систем газоочистки на ТЭС. Методы: стендовые испытания циклонного фильтра, изготовленного путем модернизации циклона ЦН-11-200, аэродинамические расчёты; численное моделирование аэродинамических параметров работы циклона-фильтра на основе методов вычислительной гидродинамики. Для математического моделирования процесса сепарации использована система уравнений, состоящая из осредненных по Рейнольдсу уравнений движения однофазного потока Навье–Стокса и уравнения движения частиц, основанного на законе Ньютона. Для определения эффективности отделения взвешенной части потока в циклоне-фильтре использован безразмерный комплекс Rer, с помощью которого численные значения параметров осаждения взвеси из многофазного потока в сепараторе найдены расчетным путем. Результаты. Анализ литературных источников показал отсутствие конструкций циклонов-фильтров, которые обеспечивали бы надлежащую (более 98 %) степень очистки выбросов без резкого увеличения энергозатрат на обработку выбросов. Проведенные опыты показали целесообразность конструктивного дополнения возвратно-поточных циклонов фильтрующей вставкой в зоне, где происходит инерционное осаждение пыли. Для определения эффективности отделения взвешенной части потока в данном циклоне-фильтре был использован безразмерный комплекс Rer. Расчеты показали соответствие результатов теоретических и натурных исследований.

Spatial variations and periodic changes in heavy metals in surface water and sediments of the Three Gorges Reservoir, China

Substantial changes have occurred in hydrological situation of the Three Gorges Reservoir (TGR) after the operation of the Three Gorges project, as have the heavy metals (HMs) pollution characteristics. In this study, concentrations of Cu, Zn, Pb, Cr, and Cd in surface water and sediments of the TGR were determined during the water impoundment period (December 2015) and water drawdown period (June 2016). The index of geoaccumulation, principal component analysis (PCA), and correlation analysis were used to analyze HMs pollution characteristics. Results showed that HMs concentrations in surface water were much lower than the quality standards for drinking water and surface water of China. The pollution levels of HMs in sediments were nonpolluted for Cr, nonpolluted to moderately polluted for Cu, Zn, Pb, and moderately polluted for Cd. In the fluctuating backflow zone, HMs concentrations in sediments during the water drawdown period were lower than those during the water impoundment period, which was attributed to that faster flow velocity during the water drawdown period resulted in less deposition of suspended solids and faster release of HMs pollutants from sediments to water. HMs concentrations of sediments at sites M14 and M17 showed similar periodic changes to those at the fluctuating backflow zone, which might be attributed to the density-stratified flow in the adjacent upstream tributaries (Meixi River and Qinggan River, respectively). Correlation analysis and PCA analysis results showed that for the sediments, Cr came from natural sources, while Cu, Zn, Pb, and Cd mainly came from anthropogenic sources.

A Stochastic Model for the Fractal Dimension Estimation of Asphaltenes Aggregation

Some of the problems associated with the transportation of crude oils are due to the presence of heavy compounds as asphaltene molecules. This work developed a stochastic model that predicts the fractal dimension of the asphaltene aggregates. It was found that the maximum value of the fractal dimension is 1.71, which corresponds to the reported experimental results. The model can be applied as a universal growing behavior for the analysis of surface roughness when solids deposition is observed in the production systems involving crude oils.

Groundwater Quality Assessment Using Fuzzy-AHP in An Giang Province of Vietnam

Along with rapid population growth in Vietnam, there is an increasing dependence on groundwater for various activities. An Giang province is known to be one of the agricultural intensification areas of The Vietnamese Mekong Delta (VMD). This study aimed to evaluate the spatiotemporal variation of groundwater quality for a period of ten years from 2009 to 2018 in An Giang. The weighted groundwater quality index (GWQI) was developed based on the fuzzy analytic hierarchy process (Fuzzy-AHP) for assigning weighted parameters. The results show that that shallow wells in the Northeast and Southeast regions of An Giang were mostly categorized under “bad water” quality with high arsenic (As) concentration over the years partly due to huge amounts of sediment deposition in monsoon season. Overall, the reason for the poor groundwater quality in An Giang was the combined effect of both natural and human activities. On the other hand, we detected high values of GWQI links with high As concentration in areas where people extract more groundwater for irrigation. Temporal variation of GWQI suggested that groundwater quality at eight wells has improved from 2009 to 2018 in the wet season as compared to the dry season. The reason behind the improvement of groundwater quality during wet season was the decrease in river discharge, which causes less deposition of suspended solids near the flood plains. Moreover, the filling of unused wells can reduce the movement of pollutants from unused wells to groundwater aquifers. Although there was not sufficient evidence to show the relationship between As and sediment concentration, the temporal reduction trend in river discharge and suspended solids was detected in An Giang. The understanding of groundwater quality can help policymakers protect and manage limited water resources in the long-term.

Conservative mathematical model and numerical simulation of batch gravity settling with coalescence of liquid-liquid dispersions

Population balance equations (PBE) provide a suitable a framework for dealing with drop breakage and coalescence. In addition, modeling of the solid particle sedimentation process based on Kynch’s theory has been successfully used and validated in mineral processing and wastewater treatment. In this work, we present a model that merges the coalescence process with hindered polydisperse sedimentation. The PBE model is projected onto a partial differential equation (PDE) system by discretizing the droplet volume. Because there is loss of mass in the system when the daughter droplets are greater than the larger species considered for the numerical solution, two terms that produce the conservation of the mass or total volume of the dispersed phase are incorporated into the PDE system. The resulting PDE system is split into two systems: homogeneous PDEs and ordinary differential equations (ODEs). The homogeneous PDEs and the ODEs are discretized using a first-order central differencing scheme and the second-order, two-stage Runge-Kutta method, respectively. The model predicts the vertical variation of the composition of the dispersed phase layer that forms at the top or bottom of the gravity settler. The proposed model was calibrated and validated through an experiment with an oil and water system. In particular, simulations illustrate the effects of: the continuity of the dispersion (oil-in-water and water-in-oil) and the standard deviation of the initial droplet volumes on phase separation quality, as well as the influence of the coalescence frequency on the average droplet volume.

Scleractinian Corals of the Arctic and High Latitudes of the North Atlantic Ocean

Only two species of scleractinian corals were found in the high latitudes of the Arctic Ocean west of the Barents Sea: Lophelia pertusa (Linne, 1758) and Flabellum macandrewi Gray, 1849. The first species has a cosmopolitan distribution; the second inhabits the Atlantic Ocean only. An analysis of the hydrodynamic environment in which these species exist has led us to conclude that the species L. pertusa preferring solid sediments is favored by increased water hydrodynamics. Fl. macandrewi, which lives on loose sediments, is also exposed to powerful water flows, which cause instability and the mobility of sandy or finely gravel sediments on the bottom, breaking the fragile skeletons of these corals. However, they adapt to such living conditions due to their extraordinary ability to regenerate. We argue that the presence of coral polyps of this species can be a marker of highly dynamic waters. Scleractinian corals are completely absent in the central parts of the Arctic Ocean, which is explained by the geological history of this region, possibly affected by water desalination, fluctuations in water salinity, and sharp changes in the intensity of phytoplankton development.

Technology of utilization of liquid wastes generated during the preparation of main oil pipelines to transport diesel fuel with produce cheap steam or warm heat carrier

The existing technology of cleaning internal surfaces of oil pipelines from oil residues and solid sediments leads to the formation of a large volume of liquid hydrocarbons contaminated with mechanical particles and various resins. Currently, in the oil industry, mobile steam generator plants of PPU 1600/100 are used to steal sections of oil pipelines. The standard nozzle burner used in the PPU 1600/100 does not allow to burn effectively liquid waste similar to contaminated liquid hydrocarbons formed during the cleaning of the inner walls of the main oil pipelines. The article presents the results of operation of steam generator sets of PPU 1600/100 with a nozzle-free burner device VGU-1.

Upflow anaerobic sludge blanket reactor and biofilter in polyethylene as an alternative of decentralized wastewater treatment in municipality of Rio Rufino – SC

Basic sanitation services are essential for promoting public health and for mitigating environmental damage. Thus, the objective of this work was to evaluate a wastewater treatment system consisting of anaerobic sludge blanket reactor and biofilter, as an alternative for the decentralized wastewater treatment in the municipality of Rio Rufino - Santa Catarina. The system was evaluated for its efficiency of removal of fecal coliforms, biochemical oxygen demand, chemical oxygen demand, soluble chemical oxygen demand, phosphorus, Total Kjhedal Nitrogen, nitrite, nitrate, sedimentable solids and maintenance of the hydrogen potential in the effluent. The treated effluent had its parameters compared to the standards established by Resolution 430/2011 of the Conselho Nacional do Meio Ambiente and Law 14.675 / 2009 of the State of Santa Catarina. It was also performed the estimate of the daily biochemical oxygen demand load, originated by the population of the municipality, and its respective impact. The effluent treated by the proposed system, when properly installed, follows what was established by the legislation, which implies in reducing the impacts caused by the municipality. In this way, the system can be an interesting alternative when it comes to decentralized wastewater treatment.

Evidence for unmonitored coal ash spills in Sutton Lake, North Carolina: Implications for contamination of lake ecosystems

Coal combustion residuals (CCRs, also known as “coal ash”) contain high concentrations of toxic and carcinogenic elements that can pose ecological and human health risks upon their release into the environment. About half of the CCRs that are generated annually in the U.S. are stored in coal ash impoundments and landfills, in most cases adjacent to coal plants and waterways. Leaking of coal ash ponds and CCR spills are major environmental concerns. One factor which may impact the safety of CCRs stored in impoundments and landfills is the storage area's predisposition to flooding. The southeastern U.S., in particular, has a large number of coal ash impoundments located in areas that are vulnerable to flooding. In order to test for the possible presence of CCR solids in lake sediments following Hurricane Florence, we analyzed the magnetic susceptibility, microscopic screening, trace element composition, and strontium isotope ratios of bottom sediments collected in 2015 and in 2018 from Sutton Lake in eastern North Carolina and compared them to a reference lake. The results suggest multiple, apparently previously unmonitored, CCR spills into Sutton Lake from adjacent CCR storage sites. The enrichment of metals in Sutton Lake sediments, particularly those with known ecological impact such as As, Se, Cu, Sb, Ni, Cd, V, and Tl, was similar to or even higher than those in stream sediments impacted by the Tennessee Valley Authority (TVA) in Kingston, Tennessee, and the Dan River, North Carolina coal ash spills, and exceeded ecological screening standards for sediments. High levels of contaminants were also found in leachates extracted from Sutton Lake sediments and co-occurring pore water, reflecting their mobilization to the ambient environment. These findings highlight the risks of large-scale unmonitored spills of coal ash solids from storage facilities following major storm events and contamination of nearby water resources throughout the southeastern U.S.

Advanced predictions of solidification in cryogenic natural gas and LNG processing

The formation and deposition of solids during the cryogenic processing of natural gas is a perennial risk for operators. Several tools are available for predicting the temperatures at which heavy hydrocarbon solids will form in cryogenic processing equipment; of these the Kohn and Luks Solids Solubility Program (KLSSP) from GPA Midstream has become an industry standard tool for predicting solid-fluid equilibria (SFE) in cryogenic processes. However, although it describes well many of the data sets generated as part of the GPA’s research program in the 1970s and 1980s, the KLSSP suffers from limitations including fixed ranges of temperature, mixture composition, no dependence on pressure and a limited set of possible freeze-out components. Here, a new software tool called ThermoFAST is presented, which overcomes these limitations and has been endorsed by GPA Midstream to replace the KLSSP. This model uses a cubic equation of state and efficient flash algorithms to enable rapid calculations of solid-liquid, solid-vapour, and solid-liquid-vapour equilibrium conditions in addition to normal vapour-liquid phase envelopes. The model has been tuned to the available solid-fluid equilibrium literature data for 58 binary mixtures and is able to represent them with an average root-mean-squared temperature deviation of only 1.7 K. It was thoroughly tested against available SLE data for multi-component LNG mixtures, and improved the accuracy of predicted melting temperatures by a factor of 7 relative to KLSSP, with an average rms deviation of only 2.0 K. The rapid flash algorithm was used to identify 26 distinct transition pathways involving solidification phenomena in LNG-relevant fluids: this includes the prediction of retrograde solidification in multiple systems (including the methane + benzene binary) where a decrease in system temperature produces a reduction in the amount of solid phase present.

Reactivity of CO2 with aqueous choline-based ionic liquids probed by solid-state NMR spectroscopy

CO2 absorption in a series of choline-based ionic liquids is investigated using solid-state 13C and 15N MAS NMR spectroscopy. Natural abundance and 13C enriched CO2 gas was purged through 50wt% aqueous solutions of alkyldimethyl(2-hydroxyethyl)ammonium threonine, [N1,1,n,2OH][Threo], (alkyl=butyl, pentyl and hexyl) and pentyldimethyl(2-hydroxyethyl)ammonium taurine [N1,1,5,2OH][Tau]. The process of CO2 absorption results in precipitation of a solid sediment, which stays in equilibrium with the liquid phase. Upon degassing of the sample, the sediment is dissolved back into the IL-aqueous phase. Solid state 13C and 15N MAS NMR data suggest that the solid sediment is composed of neutral threonine (or taurine) in the zwitterionic forms and the liquid phase contained the products of reactions between the ionic liquids and CO2 molecules. A plausible mechanism for formation of the solid sediments and the reaction products in liquid phases is suggested.

Stability of co‐crystals of caffeine with gallic acid in presence of coformers

AbstractCaffeine forms interactive complexes with several compounds. The formation and stability of caffeine's cocrystals with competing coformers has been investigated in terms of Gibbs free energy of coformer replacement from the solubility values and solubility product of co‐crystals at a given temperature. The feasibility of replacement was checked experimentally, and analysis was done by XRD, FTIR, and DSC technique. The Gibbs free energy of coformer replacement at other temperatures was predicted by using solubility values with Gibbs‐Helmholtz equation and correlating experimental solubility of coformer via nonrandom two‐liquid (NRTL) model of liquid mixtures in terms of activity coefficient and thereby predicting the coformer solubility at other temperatures. The NRTL parameters for catechin, citric acid, oxalic acid, and gallic acid have been estimated. The thermodynamic approach to determine the coformer replacement is found to be in line with the experimental results.Practical applicationsCooling of tea infusion leads to solid sediment formation called as tea cream, because of formation of many stable complexes of tea components. Several parameters such as temperature, concentration, and chemical composition, affect the formation of tea cream. Tea infusion contains caffeine along with different acids such as gallic acid, oxalic acid, and tannic acid, which can form stable co‐crystals. This study attempts to estimate the stability of the cocrystals of caffeine in the presence of different acidic coformers as a function of temperature and thus prediction and minimization of tea cream formation.

Numerical simulation of two-phase flow in screw-conveyor sedimentation centrifuge

The paper simulates the aerodynamics of a two-phase flow in the cylindrical part of the screw auger precipitation centrifuge in order to estimate the centrifugal forces in the central region of the centrifuge, due to problems of sedimentation of the solid fraction from the suspension. According to the obtained velocity field, the time and the trajectory of the deposition of solid particles of different diameters of a two-phase flow of different diameters are calculated. This is necessary to estimate the speed of rotation and the pitch of the screw for outputting solid sediment to the discharge windows. The resulting model will optimize the existing apparatus for centrifuging two-phase flows, as well as help in the design of new plants.

Three-dimensional Eulerian-Lagrangian simulation of particle settling in inclined water columns

We present three-dimensional simulations of sedimentation of suspended solids in inclined vessels using a Eulerian-Lagrangian model developed specifically for the study of solid-liquid mixtures. The simulation results reveal the three-dimensional vortical flow structures that follow the occurrence of flow instability and induce strong mixing between the particle-laden and clear-fluid layers. We show that the tubes exhibit significant spanwise variation due to the presence of wall boundary layers and are subsequently transformed into three-dimensional turbulent structures. The vortices and turbulence result in significant resuspension from the particle-laden layer and weaken the convective effect that enhances sedimentation. We show that for the present flow condition and particle size, particle inertia plays an important role in particle resuspension. Analysis of the release of potential energy is presented to examine the sedimentation efficiency under different flow conditions. We show that the time history for a typical case can be divided into development, convection, and deposition stages. The analysis for cases with different particle sizes shows that the faster settling associated with larger particles stabilizes the flow by reducing the interfacial shear while settling. From simulation results using various angles of inclination, we can find the optimal angle of inclination to achieve the greatest efficiency in settling enhancement. Finally, critical modeling aspects, including the importance of different forcing terms and two- or three-dimensional considerations, are discussed.

Effects of pressure and multiple passes on the physicochemical and microbial characteristics of lupin‐based beverage treated with high‐pressure homogenization

In this study, results showed that increasing the pressure and number of passes of high-pressure homogenization (HPH) could remarkably increase the lethality to microorganisms, shelf life, and the L*, a*,and ∆E* values of color but decrease the particle size and the b* value of color. Moreover, we observed a decreasing trend to inactivate microorganisms at a fixed pressure. When the pressure is below 100 MPa, increased pressure and number of passes could significantly decrease the solid sedimentation and viscosity of the HPH-treated lupin-based beverage. However, when the pressure reached 175 MPa and the pass number was increased from 2 to 4 and 6, no significant effects on the solid sedimentation and viscosity of HPH-treated lupin-based beverage were observed. These results indicate that increased pressure and multiple passes of HPH treatment could further decrease the microbial counts and particle size, and increase the shelf life and dispersion stability of lupin-based beverage. Practical applications HPH-treated products are smoother and have better flavor, texture, color, taste, and longer shelf life compared with non-HPH-treated products. The operating pressure, inlet temperature, and number of passes are the most important parameters of HPH treatment. In this study, we conformed that the multiple-pass approach at low pressure (<200 MPa) is viable for fluid food processing compared with the lower cumulative effectiveness of a very high-pressure single pass (>200 MPa). Moreover, low-pressure equipment showed a lower cost of maintenance. Because of the protein-rich and health benefits properties, the genus Lupinus, have been considered as an alternative of raw materials for plant-derived products. Low pressure (50, 100, and 175 MPa) combined with multiple passes could significantly increase the physicochemical and microbial characteristics of lupin-based beverage.

Influence of the Environment on the Operational Safety of a Fluidized Bed Boiler

Abstract The use of fluidized bed boilers in modern power engineering is a promising solution for clean and economically acceptable combustion of various fuels, including coal, biomass and waste, for the generation of electricity. The fluidized bed boilers are nowadays technically advanced and complex combustion facilities where all individual boiler elements are subjected to withstand continuous structural and thermal loads during their operation. Intensive loading of boiler elements can be quite easily linked with boiler operational safety and is quite often one of the main reasons for emergency shutdowns followed by necessary replacements of the damaged items. In case of industrial large-scale circulating fluidized bed boilers the frequency of unplanned shutdowns is also quite often affected by the hydrodynamics of the fluidized bed and some other parameters, such as the intensity of solids circulation, temperature, solids concentration, flue gas composition and velocity, solids accumulation and deposition, as well as the corrosion or erosion of heat transfer surfaces. The present paper briefly reports the results of authors investigation focused on the morphology and structure of some chosen elements (steel anchors) sampled from one of Polish circulating fluidized bed boilers. The anchors were degraded during boiler operation and lost their mechanical durability. In order to determine the reasons of anchors’ degradation chemical composition of the elements was determined with the use of a spark spectrometer SPECTROLAB and sample morphology was investigated with JEOL JSM-6610LV scanning microscope equipped with LaB6 cathode.