Short Start-up Period Research Articles

A bio-augmented system with Methylosarcina sp. LC-4 immobilized on bio-carriers: Towards an integrated approach to mitigate and valorize methane emissions from landfills to biodiesel

Bio-augmented systems based on methanotrophs are indispensable in curbing anthropogenic methane emissions from engineered landfills or dumpsites to curtail rising levels of greenhouse gases. Using a defined methanotroph culture immobilized on an inert material-based bio-carrier makes it possible to harness these methane emissions for creating value-added products, thus contributing to the circular bio-economy. The methane oxidation capacity of the model methanotroph Methylosarcina sp. LC-4, a prospective organism for biodiesel production using methane present in landfill gas, immobilized on several inert bio-carriers, was evaluated to identify a bio-carrier that provided optimum conditions for the process.Among the several bio-carriers evaluated, perlite and vermiculite were selected due to their high specific surface area and superior water-holding capacity, which result in the retention of nutrients and biomass and higher methane elimination capacity. While perlite showed high biomass holding capacity and methane transport, vermiculite supported a high growth of methanotrophs. LC-4 immobilized on perlite and vermiculite as the bio-carrier showed maximum methane elimination capacity (MEC) of 291.3 g m−2 day−1 and 155.5 g m−2 day−1, respectively. The low bed height of only 0.13 m and a short start-up period of 2–4 days are promising for use as alternate daily cover in a landfill. The recovered biomass had 12% (w/w) fatty acid methyl ester (FAME), with a high fraction of (∼85%) of C14–C18 saturated and monounsaturated fatty acids, suitable for biodiesel production. The combination of perlite and vermiculite increased MEC and FAME content levels. The current study demonstrated a new bio-augmented system designed with a pure methanotroph for methane elimination with a short start-up time and the valorization of the assimilated methane.

Improvement of drug processability in a connected continuous crystallizer system using formulation additive

Continuous crystallization in the presence of polymer additives is a promising method to omit some drug formulation steps by improving the technological and also pharmacological properties of crystalline active ingredients. Accordingly, this study focuses on developing an additive-assisted continuous crystallization process using polyvinylpyrrolidone in a connected ultrasonicated plug flow crystallizer and an overflow mixed suspension mixed product removal (MSMPR) crystallizer system. We aimed to improve the flowability characteristics of small, columnar primary plug flow crystallizer-produced acetylsalicylic acid crystals as a model drug by promoting their agglomeration in MSMPR crystallizer with polyvinylpyrrolidone. The impact of the cooling antisolvent crystallization process parameters (temperature, polymer amount, total flow rate) on product quality and quantity was investigated. Finally, a spatially segmented antisolvent dosing method was also evaluated. The developed technology enabled the manufacture of purified, constant quality products in a short startup period, even with an 85% yield. We found that a higher polymer amount (7.5–14%) could facilitate agglomeration resulting in “good” flowability without altering the favorable dissolution characteristics of the primary particles.

Characteristics of denitrification and microbial community in respect to various H2 pressures and distances to the gas supply end in H2-based MBfR.

The hydrogen-based hollow fiber membrane biofilm reactor (H2-based MBfR) has shown to be a promising technology for nitrate (NO3––N) reduction. Hollow fiber membranes (HFM) operating in a closed mode in an H2-based MBfR often suffer from reverse gas diffusion, taking up space for the effective gas substrate and resulting in a reduction in the HFM diffusion efficiency, which in turn affects denitrification performance. In this work, we developed a laboratory-scale H2-based MBfR, which operated in a closed mode to investigate the dynamics of denitrification performance and biofilm microbial community analysis at different H2 supply pressures. A faster formation of biofilm on the HFM and a shorter start-up period were found for a higher H2 supply pressure. An increase in the H2 pressure under 0.08 MPa could significantly promote denitrification, while a minor increase in denitrification was observed once the H2 pressure was over 0.08 MPa. Sequencing analysis of the biofilm concluded that (i) the dominant phylum-level bacteria in the reactor during the regulated hydrogen pressure phase were Gammaproteobacteria and Alphaproteobacteria; (ii) when the hydrogen pressure was 0.04–0.06 MPa, the dominant bacteria in the MBfR were mainly enriched on the hollow fiber membrane near the upper location (Gas inlet). With a gradual increase in the hydrogen pressure, the enrichment area of the dominant bacteria in MBfR gradually changed from the upper location to the distal end of the inlet. When the hydrogen pressure was 0.10 MPa, the dominant bacteria were mainly enriched on the hollow fiber membrane in the down location of the MBfR.

PECULIARITIES OF DETERMINATION OF RECONSTRUCTION POTENTIAL OF ENERGY SOURCE IN THE CONDITIONS OF AVIATION ENTERPRISES

In the context of the world economy, air transport today, among other characteristics, is characterized by high technological complexity of vehicles, increasing the safety of air transport, strengthening measures to protect aviation from acts of unlawful interference and development of modern multimodal transport technologies and infrastructure for various modes of transport. Due to the global trend, unmanned aerial vehicles have become widespread in various areas and sectors of the world economy. Meanwhile, the issue of energy security as a component of aviation security at airfields and specialized enterprises in their operation, storage and maintenance remains unresolved. The problem of this work is the synthesis of the method of determining the potential of dispersed energy sources in aviation enterprises. Combining the parallel operation of dispersed generation and network will give a synergistic effect - the emergence of new properties that were not in the components, which is manifested, in particular, in increasing factors influencing energy performance, irregularity of the total load schedule of integrated systems, reducing its unevenness in daily, weekly and seasonal sections, reducing the dependence of the frequency of electric current on power balance fluctuations. In previous studies, the authors justify the positive effect of the introduction of sources of dispersed generation in industrial enterprises, namely modularity, reliability, local governance, reducing the negative impact on the environment and short start-up period. Given the complexity of the technological process and the specifics of the operation of electrical equipment of aviation enterprises, an urgent scientific and practical task is to develop a method for determining the potential of dispersed energy sources in these enterprises. To determine the potential of sources of dispersed generation in aviation enterprises, it is necessary to have as complete and clear data on electricity supply and power consumption of electrical equipment of these enterprises during the day, as well as data on electricity consumption in the power grid, operation and load consumption. At aviation enterprises, the introduction of dispersed generation based on renewable energy sources into the general structure of power supply systems is relevant and possible. The proposed method of determining the potential of dispersed energy sources in the conditions of aviation enterprises will allow to effectively implement dispersed generation in the power supply structure of aviation enterprises.

Online Application Guidance for Heterogeneous Memory Systems

As scaling of conventional memory devices has stalled, many high-end computing systems have begun to incorporate alternative memory technologies to meet performance goals. Since these technologies present distinct advantages and tradeoffs compared to conventional DDR* SDRAM, such as higher bandwidth with lower capacity or vice versa, they are typically packaged alongside conventional SDRAM in a heterogeneous memory architecture. To utilize the different types of memory efficiently, new data management strategies are needed to match application usage to the best available memory technology. However, current proposals for managing heterogeneous memories are limited, because they either (1) do not consider high-level application behavior when assigning data to different types of memory or (2) require separate program execution (with a representative input) to collect information about how the application uses memory resources. This work presents a new data management toolset to address the limitations of existing approaches for managing complex memories. It extends the application runtime layer with automated monitoring and management routines that assign application data to the best tier of memory based on previous usage, without any need for source code modification or a separate profiling run. It evaluates this approach on a state-of-the-art server platform with both conventional DDR4 SDRAM and non-volatile Intel Optane DC memory, using both memory-intensive high-performance computing (HPC) applications as well as standard benchmarks. Overall, the results show that this approach improves program performance significantly compared to a standard unguided approach across a variety of workloads and system configurations. The HPC applications exhibit the largest benefits, with speedups ranging from 1.4× to 7× in the best cases. Additionally, we show that this approach achieves similar performance as a comparable offline profiling-based approach after a short startup period, without requiring separate program execution or offline analysis steps.

Mature landfill leachate treatment using granular sludge-based reactor (GSR) via nitritation/denitritation: Process startup and optimization

Mature landfill leachate wastewater (LLW) was characterized by high ammonia, refractory chemical oxygen demand (COD) and heavy metal contents, which limits the nitrogen removal in conventional activated sludge systems. Granular sludge is known to be more resistant to toxic compounds because of its dense structure and diverse microbial community. Here, granular sludge-based reactor (GSR) was applied with nitritation/denitritation (Nit/DNit) process for effective ammonia-rich mature LLW treatment at 20 °C. After a short startup period, the efficiencies of ammonia removal and total inorganic nitrogen removal stabilized at 99 % and 93 %, respectively, under a hydraulic retention time (HRT) of 6 h. High ammonia oxidation rate (~ 0.64 g N/g VSS/d) was achieved, with ~93 % ammonia conversing to nitrite before being reduced to nitrogen gas. Microbial analysis results revealed that Nitrosomonas (ammonia oxidizing bacteria) and Thauera (denitrifiers) were the dominant bacteria with key functional genes involved in the Nit/DNit. With an increase in the LLW loading, increased ammonia oxidation rates and biomass retention were also observed. This study demonstrated that granular sludge-based technology is feasible for mature LLW treatment.

Optimization of operational conditions and performances of pilot scale lumbrifiltration for real raw municipal wastewater treatment.

Lumbrifiltration (LF) has been promoted as a low-cost, low maintenance and efficient solution for domestic and municipal wastewater treatment especially. However, there have been limited studies investigating the optimal operating conditions and long-term performances of LF systems (especially in temperate climates). The key objectives of this study were to (i) to present an outcome of the operating conditions and associated performance of LF the systems studied in the literature regarding removal efficiencies for nutrients and organic matter (OM) in municipal and domestic wastewater (WW) treatment contexts, (ii) to generate long term and reliable results on the potential performances of LF systems for the treatment of real municipal WW (for both OM and nutrients), (iii) to optimize operational conditions such as active layer height, earthworms density, HLR and earthworms type, conditions for which it is still unclear from the current literature which are optimal, and (iv) to assess the performances of the LF in a "temperate climate" context. Overall, LF systems showed high removal efficiencies for organic matter and nutrients for all the operating conditions tested. The study also confirmed the positive impact of earthworms in achieving high level of nitrification of ammonium after a short start-up period. The system operation and performances were maintained without maintenance for the whole duration of the study (over 250days), showing the potential for keeping high level of performances for long-term periods. Recommendations are given in relation to LF system design such as optimal active layer height and hydraulic loading rate. The study also demonstrated the applicability and potential of Dendrobaena veneta as an alternative to Eisenia fetida (the latter generally being used in previous studies but are less available in some areas of Europe) for application in municipal wastewater treatment by LF.

Comparative performance of high-rate anaerobic reactors for biodegradation of soybean molasses

Soybean molasses is a residue obtained at the industrial processing of soybean to produce the soy protein concentrate. This residue is the result of the extraction of sugars from de-oiled soybean meal, which viable alternative to its disposal might be the degradation by anaerobic digestion (AD). Thus, a comparative study was performed in two high-rate technologies (UASB and ABR reactors) to evaluate the start-up time and optimum HRT required for the AD of soybean molasses under similar loading operations. The lab-scale reactors were fed with soybean molasses for 134 and 103 days under ambient conditions, respectively. Initially, the UASB reactor was operated at an organic loading rate (OLR) of 0.28 kgCOD m−3 d−1 (HRT = 48 h), while ABR reactor of 0.43 kgCOD m−3 d−1 (HRT = 36 h). OLRs were improved by reducing HRT 48 to 12 h and increasing substrate concentration (COD of 500 to 6000 mg L−1) for six different OLR in both reactors. After the fast start-up period, the UASB reactor attained values of CODTotal and CODFiltered removal efficiencies of 80% and 88%, respectively at an HRT of 24 h (3.91 kgCOD m−3 d−1) whereas ABR reactor presented 95% (CODTotal) and 97% (CODFiltered) at HRT of 36 h (3.86 kgCOD m−3 d−1) for similar OLR. By reducing HRT, both reactors have shown granular sludge flotation (sludge washout) and lower COD removal efficiencies (<80%). The experimental results revealed that high-rate anaerobic configurations (UASB and ABR reactors) can be used for the anaerobic biodegradation of soybean molasses with removal efficiency and a short start-up period.

Sustaining community-based interventions for people affected by dementia long term: the SCI-Dem realist review

ObjectivesCommunity-based support for people with earlier-stage dementia and their care partners, such as regularly meeting groups and activities, can play an important part in postdiagnostic care. Typically delivered piecemeal in...

Excellent performance of anaerobic membrane bioreactor in treatment of distillery wastewater at pilot scale

A pilot-scale anaerobic membrane bioreactor (AnMBR) was designed and optimized for the treatment of real distillery wastewater. A low hydraulic retention time of 3.5 days was reached after only 3 weeks. The AnMBR could treat up to 3.97 gCOD/L/day with high biogas production at 1.36 NLbiogas/Lbioreactor/day. The performances of an AnMBR and an anaerobic packed-bed bioreactor for treating the same wastewater were compared. The AnMBR had a shorter start-up period (21 days), a higher COD removal efficiency (96.9 %), and higher stability and methane production (0.26 LCH4/gCODinput), indicating the interest of investigating AnMBR industrialization. The membrane performance was also studied, demonstrating a long cleaning cycle interval of at least 44 days. The transmembrane pressure and Food-to-Microorganism ratio were defined to minimize membrane fouling without affecting the anaerobic digestion performance.

Non-dimensional study on the start-up process of a centrifugal pump and its related pipe system

Hydraulic transient processes sometimes bring with it violent or dramatic unsteady phenomenon, which would interfere the normal operation or even damage the system. The start-up of a centrifugal pump with cavitation can lead to serious transient phenomenon. One dimensional calculation (Method of characteristics) was widely used to solve transient problems, but its drawback is lacking of details for the flow characteristics inside the pump, 3D simulation for transient process simulation needs huge computer resources. A simulation method that coupled MOC and 3D simulation (CFD) was frequently used for solving complex transient problems in these years. The results of the coupling simulation are usually complex when cavitation happens and disappears quickly during the short start-up period, a simplified method to describe the process is necessary. A centrifugal pump and its related system were simulated with a coupling method. Dimensionless mass flow rate, head and cavitation conditions of the pump was used to analyse the start-up process. It was proved that the non-dimensional study method can make the whole process more intuitive and easier to understand.

Power-generating trees: Direct bioelectricity production from plants with microbial fuel cells

Although plant-microbial fuel cells (PMFCs) have been considered as an alternative approach to utilize plants as an energy source, the application of a conventional PMFC coupled with rhizodeposits is immensely limited by environmental factors and plant species. In this research, we suggested a new concept for a device that can directly generate continuous bioelectricity from the plant stem associated with microbial fuel cells (MFCs), in which Pachira macrocarpa and Populus alba were employed. Compared with a conventional PMFC, the novel PMFC coupled with the plant stems produced more stable and continuous bioelectricity without oscillatory behaviour as well as a much shorter start-up period. The stem-coupled PMFCs produced bioelectricity that were operated at least 40 days. P. alba coupled PMFC showed higher power output compared to P. macrocarpa counterparts and the maximal power densities were 7.61 mW m−2 and 3.60 mW m−2 anode surface, respectively. Besides, we explored the response of the novel PMFC to different substrate concentrations and observed that the cell voltage effectively increased after the injection of moderate substrate concentrations. Moreover, the anodic bacteria formed a commensal relationship with the plant.

Performance evaluation of a lab-scale moving bed biofilm reactor (MBBR) using polyethylene as support material in the treatment of wastewater contaminated with terephthalic acid

Untreated terephthalic acid (TPA) wastewaters with high organic loads will cause severe environmental pollution problems. In this study, a lab-scale moving bed biofilm reactor, where biomass of Delftia sp. WL-3 is attached to polypropylene carrier elements, has been tested for TPA bioremediation at 25–27 °C. The system achieved stable operation after a short 15-day start-up period. During the operation period of 65 days, stable chemical oxygen demand (COD) and TPA removal efficiencies of 68% and 76% were maintained with an organic load rate (OLR) and hydraulic retention time of 2.5 kg COD·(m3·d)−1 and 24 h, respectively. In addition, the Scanning Electron Microscope (SEM) showed that high-densities of WL-3 biomass accumulated on the surface of the carrier and formed a rich biofilm, indicating polypropylene carrier can improve the degradation efficiency. On the contrary, the biodegradation ability of stain WL-3 without the polypropylene carrier declined significantly with removal efficiencies of 10% and 15% for COD and TPA. Furthermore, the system exhibited excellent robustness to different OLR and influent matrix ratios, indicating its potential for applications in the treatment of TPA-containment wastewater in the field.

A comparative evaluation of an integrated hybrid bioreactor treating industrial wastewater

An integrated hybrid bioreactor (IHB) and integrated suspended bioreactor (ISB) coupling aerobic, anoxic and settling units was evaluated for industrial wastewater treatment with and without the installation of a rectangular hollow engraved submerged Perspex media in the aerobic unit. Bioreactor performance was examined at different overall hydraulic retention times of 36, 12, 7.2, 5.1 and 4 days, respectively. Nitrogen mass balance was analyzed to examine the inhibitory effects of metabolic by-products on nitrification in IHB. Both bioreactors exhibited a short start-up period during acclimatization. Results show a lower effluent COD concentration of 15–85 mg/L in IHB and 38.6–124 mg/L in ISB. Effluent ammonia-nitrogen was 0.65–3.5 mg/L in IHB and 0.3–4.5 mg/L in ISB. Effluent nitrate and nitrite were low in both bioreactors but lower in IHB. Mass balance analysis in IHB indicated that nitrate was the dominant ammonia metabolite and decreased with reducing HRT. Microfauna investigation showed that free swimmers, crawling and attached ciliates were major protozoans in IHB while free swimmers and attached ciliates were dominant protozoans in ISB. Kinetic evaluation demonstrates that microbial growth was higher in IHB. The Y, kd, μmax and Ks for IHB was 0.1 g VSS/g COD, 0.02 per day, 0.81 per day and 1.26 g/m3 with a correlation coefficient (R2) of 0.978 while it was 0.118 g VSS/g COD, 0.04 per day, 0.635 per day and 3.93 g/m3 with a correlation coefficient (R2) of 0.988 in ISB. This study demonstrates that while both ISB and IHB were effective for industrial wastewater treatment, IHB performance was comparatively higher due to the inclusion of the submerged media.

Biofilter treatment of gas phase β-caryophyllene at an elevated temperature

ABSTRACTExperiments were carried out to test the capacity for a laboratory-scale biofilter operated at an elevated temperature level (∼50°C) to remove an air stream containing β-caryophyllene, a naturally occurring sesquiterpene of environmental concern emitted from wood-related industrial facilities. A water jacket was used to maintain high temperatures in a laboratory-scale biofilter. Inocula, pollutant loading and nutrient supply rate effects were evaluated over 84 days of biofilter operation. The start-up process took over two months when citrus peels were used as inocula while a relatively short start-up period was achieved after introducing forest compost products. While using a sparged-gas bioreactor to cultivate an enrichment culture for 97 days, removal efficiencies in excess of 80% were observed after 18 days. At empty bed contact times of 50 s and at a pollutant loading rate of 3.05 mg C/L/hr, removal efficiency levels reached 90% and the elimination capacity level reached 2.29 mg C/L/hr, corresponding to an elimination capacity of 2.60 mg β-caryophyllene/L/hr. Collectively, these results demonstrate that β-caryophyllene can be successfully removed from contaminated air using a biofilter operated at a high temperature (∼50°C), expanding the temperature range within which biofilters are known to biodegrade sesquiterpenes.

Treatment of high-strength purified terephthalic acid (PTA) wastewater using a magnetic porous ceramic support in laboratory-scale anaerobic-aerobic fluidized bed reactors

Laboratory-scale anaerobic-aerobic fluidized-bed bioreactors (FBR) with porous magnetic ceramics as support were successfully applied to treat purified terephthalic acid (PTA) wastewater. After a short 14-day start-up period, the system was stably operating. During the 40 d stable period, the system organic loading rate (OLR) increased from 6.68 to 23.87 kg chemical oxygen demand (COD)/(m3d), the effluent COD and PTA were below 90 and 30 mg/L, respectively. The FBR presented excellent COD and PTA removal efficiency with a low hydraulic retention time (HRT) value of six hours. The growth kinetic parameters suggested that the biomass in FBR possess high maximum specific growth rate (μmax = 2.22 d−1) and good tolerance to varied OLR (Ks = 258.67 mg COD/L).

A comparison study of the start-up of a MnOx filter for catalytic oxidative removal of ammonium from groundwater and surface water

As an efficient method for ammonium (NH4+) removal, contact catalytic oxidation technology has drawn much attention recently, due to its good low temperature resistance and short start-up period. Two identical filters were employed to compare the process for ammonium removal during the start-up period for ammonium removal in groundwater (Filter-N) and surface water (Filter-S) treatment. Two types of source water (groundwater and surface water) were used as the feed waters for the filtration trials. Although the same initiating method was used, Filter-N exhibited much better ammonium removal performance than Filter-S. The differences in catalytic activity among these two filters were probed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and compositional analysis. XRD results indicated that different manganese oxide species were formed in Filter-N and Filter-S. Furthermore, the Mn3p XPS spectra taken on the surface of the filter films revealed that the average manganese valence of the inactive manganese oxide film collected from Filter-S (FS-MnOx) was higher than in the film collected from Filter-N (FN-MnOx). Mn(IV) was identified as the predominant oxidation state in FS-MnOx and Mn(III) was identified as the predominant oxidation state in FN-MnOx. The results of compositional analyses suggested that polyaluminum ferric chloride (PAFC) used during the surface water treatment was an important factor in the mineralogy and reactivity of MnOx. This study provides the theoretical basis for promoting the wide application of the technology and has great practical significance.

Start-up phase of a UASB-septic tank used for high strength municipal wastewater treatment in Mexico

The objective of this work was to assess the performance during the start-up phase of a Upflow anaerobic sludge blanket (UASB)-septic tank for municipal wastewater treatment in Mexico City. A lab scale UASB-septic tank (62 L total volume, acrylic), consisting of three chambers treated high strength municipal wastewater at ambient temperature (16 °C–24 °C), under 72 h Hydraulic retention time (HRT) during three months. Total and soluble chemical oxygen demand (COD), total biological oxygen demand (BOD5), total solids and total suspended solids (TSS) removals were 75.2 ± 6.5%, 54.8 ± 6.7%, 64.2 ± 4.8%, 25.9 ± 5% and 82.9 ± 5%, respectively. These results are comparable with the removals reported in other works with similar arrangements; and are similar even with average removals of COD, BOD and TSS in UASB reactors installed in Latin America. The good performance obtained showed that it is possible to achieve a short start-up period with UASB-septic tank if it is inoculated with anaerobic sludge. These findings also evidenced the feasibility and reliability of the UASB-septic tank system for decentralized wastewater management in Mexico.

Development of a Denitrifying Biofilter with Short Start-up Period

In the present work, a novel down-flow biofilter with four identical layers was developed for the de-nitrification of 100 mg L-1 nitrate contaminated wastewater, flowing horizontally from one layer to another in a continuous fashion. This biofilter can be applied for long-term continuous wastewater treatment without any need to whole system shutdown and backwashing. The clogged layer or the deactivated section can be easily spotted and repaired while the system is under continuous operation. To attain a short startup period, the effect of two main constructional parameters, namely, filter media and inoculants source, were then investigated.. Two studied filter media were sand and woodchips. The pure culture of Saccharomyces cerevisiae and the mixed cultures of activated sludge and wastewater were three common inoculants under investigation. The biofilter packed with woodchips seeded with the wastewater resulted in the least startup period of about 3 days with a steady nitrate removal efficiency of 90 %.

Gas-cooled thorium reactor with fuel block of the unified design

Scientific investigation aimed at the implementation of advance technological platform is carried out in Russia based on the ideas of nuclear fuel breeding within closed fuel cycle and on the physical principles of fast reactors. Innovation design of low-power reactor facilities also fall under the new technological platform. High-temperature gas-cooled nuclear reactors operated with thorium fuel load possessing advantageous features of transportability, factory prefabricated manufacturing, short on-site assembly and start-up period and ability to work during extended time periods without fuel reloading represent promising direction of development in this area of nuclear power generation. It is specifically this type of low-power nuclear reactors brought to commercially competitive level that must form the basis of regional power generation in Russia. The objective of the present study is to develop the concept of low-power inherently safe thorium-fueled nuclear power installation based on the unified design of the fuel block.Scientific research and numerical experiments were performed using verified computer codes of the MCU-5 series, advanced libraries of evaluated nuclear data (ENDF/B-VII.0, JEFF-3.1.1, JENDL-4.0, ROSFOND, BROND, BNAB and others) and multi-group approximations.Analysis of information materials pertaining to the use of thorium as fuel element in rector facilities of the new generation and of its future potential was performed in the present study. Results of the first phase of neutronics studies of 3D model of high-temperatures gas-cooled reactor facility on the basis of unified design of the fuel block are presented. Calculation 3D model was developed using the software code of the MCU-5 series. Several optimal configurations of the reactor core were selected according to the results of comparison of neutronics characteristics of the examined options for the purpose of development of small-size modular nuclear power installations with power up to 60MW. Results of calculations of reactivity margin of the reactor, neutron flux distribution and power density profiles are presented for the selected options of reactor core configuration.