Sharp Fluctuations Research Articles

Clash of temporalities: Ephemerality and embodied time in Welcome to Our Hillbrow

ABSTRACT Drawing upon Ann Laura Stoler’s concept of “ruination”, this article critically examines the depictions of time and temporalities in Phaswane Mpe’s novella Welcome to Our Hillbrow (2001) to explore the dynamically persistent imperial formations that are difficult to notice in the text. These temporalities serve as reflections of pre-existing social issues in post-apartheid South Africa such as apathy, historical amnesia, and xenophobia. The sharp fluctuations of the everyday and the looming sense of anxiety disconnect the Hillbrowans’ perception of their present from the longue durée of empire. This disconnection reduces the characters’ judgement of historical and socio-economic problems as affecting failings of individual morality and xenophobia. Furthermore, Mpe reveals the fluidity of time and space in Hillbrow through the recurring motifs of walking and sharing stories. This allows the characters to envision horizons beyond their immediate experiences and rediscover their lost capacity for remembering and self-recognition in the other.

Importance of the electron plasma parameter for excitation of chorus and formation of magnetic field irregularity in the region of their excitation

A threshold condition has been established for excitation of VLF electromagnetic radiation with a chorus structure of the dynamic spectrum in the daytime magnetosphere using the BPA (Beam Pulse Amplifier) mechanism for amplifying short noise electromagnetic pulses. The kappa distribution was used as a model function of the electron velocity distribution in the magnetosphere. Calculations performed for this distribution have shown that the threshold for excitation of chorus largely depends on the electron plasma parameter equal to the ratio of gas-kinetic pressure of electrons to magnetic pressure. This pattern is not contradicted by the dependence of the probability of excitation of chorus on the degree of magnetic field irregularity, which we derived from observations made by the Van Allen Probe spacecraft. It is sharp fluctuations in the magnetic field strength near its local minima outside the plasmasphere where the radiation under study can be excited. If there is an irregularity, the probability of detecting chorus is >70 %; and if there is no or very low irregularity, the probability of the absence of any emissions is ~80 %. The results indicate a common reason for the excitation of chorus and the magnetic field irregularity — a small but finite value of the plasma parameter.

Существенность величины плазменного параметра электронов для возбуждения хоров и формирования нерегулярности магнитного поля в области их возбуждения

A threshold condition has been established for excitation of VLF electromagnetic radiation with a chorus structure of the dynamic spectrum in the daytime magnetosphere using the BPA (Beam Pulse Amplifier) mechanism for amplifying short noise electromagnetic pulses. The kappa distribution was used as a model function of the electron velocity distribution in the magnetosphere. Calculations performed for this distribution have shown that the threshold for excitation of chorus largely depends on the electron plasma parameter equal to the ratio of gas-kinetic pressure of electrons to magnetic pressure. This pattern is not contradicted by the dependence of the probability of excitation of chorus on the degree of magnetic field irregularity, which we derived from observations made by the Van Allen Probe spacecraft. It is sharp fluctuations in the magnetic field strength near its local minima outside the plasmasphere where the radiation under study can be excited. If there is an irregularity, the probability of detecting chorus is >70 %; and if there is no or very low irregularity, the probability of the absence of any emissions is ~80 %. The results indicate a common reason for the excitation of chorus and the magnetic field irregularity — a small but finite value of the plasma parameter.

Exogenous nitric oxide and hydrogen sulfide as biotechnological tools for enhancing plant adaptation to cold

The challenge of increasing plant tolerance to low temperatures is still relevant despite the upward trend in the average temperatures on Earth. Sharp temperature fluctuations during growing periods and cultivation of thermophilic crops in more northern latitudes increase the likelihood of plants being damaged by cold. Physiologically active substances, primarily hormones and signalling molecules, are considered to be effective for increasing plant tolerance to extreme temperatures. In the last decade, among such compounds, researchers' and practitioners' considerable attention has been paid to gasotransmitters – gaseous substances that are synthesized by living organisms and perform signalling functions. The review analyses the molecular mechanisms of stress protective effects of two major gasotransmitters – nitric oxide (NO) and hydrogen sulfide (H2S). In particular, the physiological effects of gasotransmitters that are attributed to their ability to cause post-translational modifications of numerous target proteins as well as those related to their functional interactions with other signaling intermediaries, primarily ROS and calcium ions, are discussed. The available data on the actions of donors of these gasotransmitters on thermophilic and cold-tolerant plants are summarized. Particular attention is paid to the influence of exogenous NO and H2S on the antioxidant system in plants, their ability to accumulate osmolytes and other low-molecular compounds with multifunctional stress protective effects. Data on the influence of gasotransmitters on fruits during low-temperature storage are analysed separately. It is emphasized that increased storability of fruits under the influence of NO and H2S donors is largely controlled by the ability of both gasotransmitters to inhibit ethylene synthesis. It was concluded that exogenous nitric oxide and hydrogen sulfide could be effective tools for increasing tolerance of different plant taxon’s to low temperatures and used in crop production and storage technologies for fruits and vegetables.

Research on Change Point Detection during Periods of Sharp Fluctuations in Stock Prices–Based on Bayes Method β-ARCH Models

Research on Change Point Detection during Periods of Sharp Fluctuations in Stock Prices–Based on Bayes Method β-ARCH Models

Androdioecy in Ranunculus ficaria ssp. ficaria (Ranunculaceae)

Androdioecy was for the first time studied in detail in the fibrous-rooted herbaceous ephemeroid polycarpic plant Ranunculus ficaria ssp. ficaria in the Moscow Region during 2019–2023. It has been established that this subspecies produces two types of flowers: perfect and staminate (remains of carpels with reduced non-functioning stigmas are preserved). Perfect flowers and their component parts are always larger than those of staminate flowers. Populations consist of three types of individuals: with perfect flowers exclusively, with perfect and staminate flowers, and with staminate flowers only. Synflorescence of R. ficaria ssp. ficaria is a closed thyrsus, the subunits of which are dichasia. In andromonoecious plants, perfect flowers are located on the top of the thyrsus axis and take a terminal position in paracladial dichasia, while staminate flowers are formed exclusively on the lateral axes of dichasia. In the five studied populations, plants with perfect flowers predominate (from 86.3 to 93.7%). Over a five-year observation period, individuals of different sexual forms did not change the sex of flowers, and the sex ratio in populations remained stable without sharp fluctuations.

Volatility Spillover Effect of NCDEX Spot and Futures Prices in Spices

This research is an attempt to assess the volatility in spot and futures prices in spices on NCDEX. Spot price and futures price Volatility is prominent indicators of the commodity futures market to protect the interest of beneficiaries and to hedge sharp price fluctuations in commodity markets. The study tested price patterns using data with 1777 observations for FY2015 to FY2022 daily spot and futures price series of near month contracts. VECM test and EGARCH were computed to examine spot and futures prices for three selected spices, namely jeera (cumin), turmeric and coriander. The results revealed that Turmeric and Coriander had significant bidirectional relationship and Jeera had significant unidirectional relationship between futures and spot market prices. Higher half-life (days) values of futures prices indicates more stability than spot prices of selected spices. Higher asymmetric effect value of spot market indicates higher volatility impacts because of noisy shocks than futures market.

Dynamic Analysis of the Multichannel Supply Chain Under Carbon Subsidy Policy

For achieving the goals of carbon peaking and carbon neutrality, the government will further strengthen subsidies to enterprises for carbon emission reduction. This paper investigates the long-term repeated game behavior of manufacturer and retailer in multichannel supply chains under three different forms of government subsidies. The long-term repeated game behavior of manufacturer and retailer is studied under the manufacturer green innovation subsidy model (IS model), manufacturer production subsidy model (MS model) and retailer sales subsidy model (RS model). Under three situations, excessive price adjustment can easily lead to system instability and sharp fluctuations in profits. Two methods are used for chaos control and management, and the parameter adjustment control method is found having more advantages for system re-stabilization.

Optimization study for cement-based grout mixture ratio of shield tunnel considering spatiotemporal evolution of grout buoyancy

The grout buoyancy for segments during shield tunnel construction can cause significant floating displacement or even cracking of the segments, and the grout buoyancy is directly related to the grout buoyancy volumetric weight (GBVW). This study proposes an optimization process for the mixture ratio of cement-based grout based on the actual engineering environment. Based on a self-designed GBVW test instrument considering the interaction between grout and strata, this study reveals the evolution law of GBVW and the 3D spatial distribution law of grout buoyancy under different mixture ratios in different strata. Then, this study calculates the segment displacement under slurry buoyancy by the multi-factor coupled numerical calculation model. Research shows that the GBVW in different strata exhibits an evolutionary characteristic of sharp fluctuation-rapid decrease-slow decrease-complete disappearance. The upward precipitation of aqueous solutions in grout in different strata occurs during the stage of GBVW sharp fluctuations, and the decrease in GBVW is mainly accompanied by the seepage of aqueous solutions into the lower strata. The average GBVW and the duration of GBVW in muddy soil are larger than those in silty soil and coarse sand, respectively. An increase in the water binder ratio will reduce the GBVW and accelerate the dissipation of GBVW, while an increase in the bentonite water ratio will promote the growth of GBVW. The lower the strata permeability, the more easily the average GBVW is affected by the water cement ratio. The peak GBVW is more easily affected by the water binder ratio, and the duration of GBVW is more easily affected by the water cement ratio.

Prerequisites for cultivating frost-resistant peach varieties in the Right-Bank part of the Western Forest-Steppe of Ukraine

The necessity of cultivating frost-resistant peach varieties in the Forest-Steppe zone of Ukraine arises due to frequent sharp fluctuations in air temperature during the winter-spring period. Their cultivation can mitigate the impact of weather conditions, ensuring stable fruit production of this crop. The study aimed to analyse the prospects for growing peaches (Prunus persica Mill.) using intensive technologies under changing climate conditions. An analysis of the peach-growing situation revealed that it is a widely cultivated drupe in Ukraine and globally. The main countries leading in peach fruit production were identified: China, Italy, Turkey, Greece, and Spain. Despite a 24% increase in global peach production between 2013 and 2023, the demand for this crop has also risen, leading to a deficit and increased imports to Ukraine. Calculations of the scientifically justified annual consumption norms for peaches showed a shortfall of 187 thousand tonnes in production, with current production standing at 11.2 thousand tonnes. Several factors hindering the expansion of peach orchards were identified. The development of frost-resistant varieties by breeders, suitable for cultivation in the Forest-Steppe of Ukraine, alongside changing weather conditions, offers opportunities for the safe cultivation of peaches in the region. An analysis of the weather conditions in the Right-Bank part of the Western Forest-Steppe of Ukraine was conducted. It was found that between 2013 and 2023, there was a significant increase in the total active temperatures, with 2023 recording a maximum of 3,777°C. At the same time, precipitation decreased by 58%, amounting to only 325 mm. Considering the changing weather conditions and the development of new frost-resistant varieties, which have expanded the peach cultivation zone to northern regions of Ukraine, it is essential to prepare and implement specific measures to adapt the horticultural industry to peach cultivation in these new regions to meet domestic market demands. It is recommended to initiate trials in irrigated horticulture and develop new methodological guidelines to provide scientific support for establishing perennial peach orchards in the Right-Bank part of the Western Forest-Steppe of Ukraine

Формирование цифровой модели угольного месторождения в горно-геологической информационной системе МАЙНФРЭЙМ

Digitalization of enterprise management using Russian software is the main trend in the development of the country's mining sector. Sharp fluctuations in demand and prices in the mineral markets, as well as the development of technical tools for mechanization and automation of technological processes along with a systematic increase in their cost affect the financial performance of mining companies. This determines the need for a rapid adoption of technical, technological and organizational decisions, which, along with the requirements of the company's owners and regulators to obtain prompt, reliable and the most complete information about the production process explains the urgent need for the prompt introduction of digital control systems for mining operations. In the article the authors describe an algorithm to design a digital model of the mining and geological system, including a digital geological model of the deposit, digital models of mine workings and the surface topography, based on the experience of creating three-dimensional digital models of complex-structured coal deposits. The basic software suite for designing a digital management system for mining operations is the MINEFRAME mining and geological information system developed at the Mining Institute of the Kola Scientific Center of the Russian Academy of Sciences. MINEFRAME allows to perform a full range of tasks aimed at creation of a digital 3D model of the mining and geological system for a coal deposit with the possibility to account for the complex bedding in the modelling. High accuracy and correctness of the input geological sampling data is achieved by means of tools to check for errors in the tables of borehole collar coordinates, inclinometry and sampling. The wireframe modelling methods implemented in MINEFRAME provide the possibility to create wireframe models of seams with high detail in the fracture zones.

CORN FOR GRAIN IN CONTINUOUS GROWING UNDER DIFFERENT FERTILIZER SYSTEMS AND WEATHER CONDITIONS

On the experimental field of the Poltava State Agricultural Experimental Station named after M. I. Vavilov of the The Institute of Pig Breeding and Agro-Industrial Production of the National Academy of Agrarian Sciences of Ukraine, during 1984-2023, on typical chernozem in conditions of unstable moisture of the Left-Bank Forest-Steppe, were conducted researches to study the continuous growing of corn for grain and its productivity. Precipitation is the leading factor in providing corn with available moisture in this region. Different hydrothermal conditions, especially the amount of moisture during the agricultural year and the vegetation, led to sharp fluctuations in grain yield over the years, which occurred in a wide range. The analysis of the average values ​​of corn productivity for each 10 consecutive years of conducting these studies made it possible to establish that during the first decade of observations, the dynamics of this indicator in subsequent periods took place in the paradigm of its growth, albeit at a different level. Maize grain yield and its correlation with different weather conditions and fertilization systems, regardless of the replacement of maize hybrids, ranged from direct to inverse and from low to high. Long-term application of different doses and ratios of organic and mineral fertilizers contributed to changes in both quantitative and qualitative indicators of humus in the soil. It was determined that the content of total carbon in the fertilized areas was higher by 3,0 and 3,3 relative percent compared to the unfertilized ones. Special attention was paid to the ratio between humic and fulvic acids, which directly depends on the fertilization system. The different effect of this agrotechnical measure on the amount of humus accumulation in the soil is shown. Thus, in areas without fertilizers (control), its accumulation occurs at the level of an average indicator and a weak effect of organic acids on the mineral part of the soil, while under the organo-mineral fertilization system, this process takes place intensively, and the mineral part remains almost unchanged.

ЭПИДЕМИОЛОГИЧЕСКИЙ АНАЛИЗ РАКА МОЛОЧНОЙ ЖЕЛЕЗЫ И ОСОБЕННОСТИ ОКАЗАНИЯ МЕДИЦИНСКОЙ ПОМОЩИ ЖЕНЩИНАМ В ЧУКОТСКОМ АВТОНОМНОМ ОКРУГЕ

Relevance. Breast cancer is one of the first places among all types of oncological pathology both in the Russian Federation and around the world. At the same time, over the past decade there has been a significant increase in the incidence of this pathology; the average annual growth rate in the Russian Federation reached up to 1.72%, which is a very worrying sign. The aim of the study is analysis of the morbidity and mortality rates from breast cancer in the female population of the Chukotka Autonomous Okrug, as well as identification of the features of medical care and prevention of identified malignant neoplasms of the breast in the study area. Materials and methods. The analysis was carried out on the basis of information materials from the Unified Interdepartmental Information and Statistical System, the Federal State Statistics Service, and documents from regional executive authorities in the field of healthcare. Statistical indicators of morbidity and mortality from malignant breast diseases in women from 2011 to 2021 (per 100,000 population) were studied; the results obtained in the region were compared with those in the Russian Federation as a whole. To assess the general and annual trend, its degree of reliability, a trend line was constructed and the value of the approximation coefficient R2 was calculated, which in all cases turned out to be acceptable. The results of the study. Morbidity and mortality from malignant neoplasms of the breast in women living in the Chukotka Autonomous Okrug differed significantly from the national average. The annual changes in the region had quite sharp fluctuations. However, in general, the trend line did not have sufficient positive characteristics. In addition, higher morbidity and mortality rates in the region, compared with the national average, can be considered a negative point.

Aerothermal Performance Robustness and Reliability Analysis of Turbine Blade Squealer Tip With Film Cooling

Abstract The uncertainty quantification in the turbine components' aerodynamic and heat transfer performances is widely considered to be the most challenging topic due to its intricate and nonlinear characteristics. This paper first proposes an efficient uncertainty quantification method based on an original parallel framework combining Polynomial Chaos Expansions (PCE) with two forms (stochastic response surface-based and Galerkin projection-based) and the Universal Kriging method. The rigorous mathematical tests are performed to verify the reliability and computational efficiency of the proposed method, and the results support that this method can dramatically reduce computational samples compared to the conventional PCE method while maintaining computational accuracy. Then, the genetic algorithm was introduced to establish an efficient uncertainty quantification framework, and it is applied to the aerothermal performance robustness investigation of the GE-E3 rotor blade tip with and without film cooling. Based on the findings of uncertainty quantification, the injection of cooling air drastically enhances the unstable tendency of the flow and thermal fields, resulting in the actual aerothermal performance of the squealer tip being much lower than that predicted by deterministic calculations. The setting of the film cooling, although effective in reducing the heat flux around the cooling holes, also induces more chaotic flow and thermal fields, leading to sharp heat flux fluctuations around the cooling holes. Finally, our novel reliability analysis algorithm, rooted in the quantification of uncertainty, corroborates the assertion that the introduction of coolant gas, while extending the operational longevity of turbine blades, confers only marginal improvements in the mitigation of lifespan variability. The comprehensive lifespan assessment elucidates that the mean operational longevity of the conventional squealer tip design stands at an estimated 16,169.44 h, accompanied by a standard deviation of 2,750.31 h. In stark contrast, the mean operational longevity of the squealer tip integrated with film cooling measures a significantly enhanced 17,035.17 h, exhibiting a standard deviation of 2,492.73 h. Consequently, the operational lifespan of the conventional squealer tip experiences a decrement of 10.17% in comparison to the anticipated mean lifespan, whereas the reduction for the film-cooled squealer tip registers at 5.36%.

Biologically active substances and safety of apples of different varieties of the Ural selection

Fresh apple fruits contain various components, including mono-, di- and polysaccharides, organic acids, triterpenoids, phytosterols, polyphenols, protein, vitamins, and macro- and microelements humans need. The purpose of the research was to study the biologically active substances and safety of apples of five varieties of winter and autumn ripening: Pervouralskaya, Krasa Sverdlovskaya, Blagovaya Vesti, Sverdlovchanin, Ekrannoe - to identify the most valuable fruits from the standpoint of modern nutritionology. The apple trees grew in equal climatic and agrotechnical (drip irrigation and fertigation) conditions IP GK(F) H Filippova A.A. (Chelyabinsk region, Kaslinsky district, Grigoryevka village). It was found that the content of insoluble dietary fiber in apples of the studied varieties did not have sharp fluctuations; the variability of the indicator was 14.3%. On the contrary, the amounts of vitamin C, pectin, polyphenols, and flavonoids had significant variability - up to 275, 100, 61, and 50%, respectively, depending on the variety. Safety indicators (content of Hg, Pb, patulin, HCH, DDT) in apples did not exceed the standards of TR CU 021/20H. The nitrate content in fruits was typical for the products of intensive apple orchards. At the same time, Pb levels varied from 0.036 to 0.103 mg/kg, nitrates - from 23.4 to 35.4 mg/kg. Increased amounts of studied biologically active substances and low levels of contaminants make it possible to classify apples of the Pervouralskaya and Krasa Sverdlovsk varieties as the best fruits of this apple orchard.

Enhancing the role of dynamic capabilities of the coal companies under the conditions of sharp price fluctuations at the international markets

In recent years, international coal markets have been facing a trend of a growing number of sharp price fluctuations during a year. This can be regarded as the evidence for the increasing intensity of market competition as well as for the growing number and significance of the external environment factors affecting the world coal market. Actually, the coal market players have to operate in the conditions of unstable prices and external limitations that in their turn require searching for new sales markets, changing logistics routes, product lines, production and technological processes, etc. It results in the increasing significance of dynamic capabilities of coal companies – organizational capabilities on changing the portfolio of resource and capabilities in response to the changing competition at the market. In the conditions of growing volatility of coal markets the adaptation capabilities of a company become a basis for its economic effectiveness and competitiveness as well as for the viability as a whole as it allows to accelerate the process of making decisions about the necessary transformations and evaluate the risks, and are crucial for the implementation of new projects. Any activities on the evaluation and development of dynamic capabilities are possible only inside a company. This task should be solved at the strategic level of decision-making alongside with identifying the company’s individual priorities for development of organizational capabilities lying in the basis of dynamic capabilities of a company.The article deal with the author’s definition of the basic categories of dynamic capabilities implemented for the coal industry. The definition presents the priorities for operation in the current conditions and the capability to transform and accept new business-models, develop analytical capabilities and skills of acquisition and alliances with other companies.

Biochemical indices of blood protein metabolism as criteria of broiler nutrition adequacy

The experiments were conducted on the broiler chickens of the cross "Smena-9" in the vivarium of the Selective Genetic Centre "Zagorskoe Experimental Breeding Farm" in Sergiev Posad. The results of the blood plasma biochemical tests showed wavelike changes in the trypsin activity at all ages stu- died. The increased concentration of total protein at 7 days of age in all groups could have been induced by switching from endogenous feed when receiving exogenous feed containing more protein than the yolk sac. The age dynamics of the alkaline phosphatase activity had sharp fluctuations throughout the whole rearing period. At 1–7 days of age, there was an increase in the phosphatase activity with a subsequent decrease until 35 days of age relative to the control in all groups. The peak of high activity of this enzyme occurs on the 7th day – 31030 units/l in the control group and on the 14th day in the experimental group 2. Thereafter, there is a gradual decrease in the activity of this enzyme. A sharp increase in the level of alkaline phosphatase in the blood of broiler chickens at 7–21 days of age indicates intensive growth and formation of the organism, but a sharp surge in activity at 7 days of age could also be caused by the transition to a new diet, which in itself is a stress factor. A decrease in the activity of this enzyme at 28–35 days of age indicates a slowdown in the growth process. Consequently, the purpose of this study was to investigate the biochemical composition of blood in different periods of post-embryogenesis of broiler chickens of the cross "Smena-9" at changing the level of protein in the diet, which in this case remains a relevant and informative source of information on the effect of changes in the ingredient composition of feed on the bird organism as a whole.

DRIVER DROWSINESS DETECTION SYSTEMS

Car accidents are frequently caused due to many reasons like drowsiness, drunkenness or tiredness, which has serious consequences for traffic safety. Numerous factors, such as fatigue, intoxication, or drowsiness, commonly contribute to car accidents, which have detrimental effects on traffic safety. Many fatal collisions might be avoided if sleepy drivers were warned beforehand. Many sleepiness detection technologies are available to identify and warn drivers of any indications of inattention while driving. Sensors in self-driving cars must be able to detect whether a driver is sleepy, agitated, or experiencing sharp emotional fluctuations. Thus far There have been numerous recommendations for enhanced warning systems to prevent sleepy driving. When these systems detect a significant lane departure, a change in the headway distance, or other indications of subpar driving, they sound an alarm. These systems rely heavily on machine learning algorithms, which allow them to learn and adjust to unique driving patterns and characteristics. In supervised learning, models are trained on labelled datasets to discriminate between awake and sleepy states. These approaches are widely used for classification tasks. Unsupervised learning techniques are also applied for anomaly detection, which finds departures from typical driving behaviour. The incorporation of cutting-edge sensors like facial recognition cameras and brainwave sensors, which offer more thorough insights into the driver's condition, has recently improved driver sleepiness detection systems. Moreover, these systems are more accurate and responsive when real-time data processing and cloud-based analytics are used. KEYWORDS Drowsiness-detection, Driver-Fatigue, Computer Vision, Real Time, survey, Eye Tracking Technology, Automotive Safety Systems, Driver Assistance Systems, Real-time Drowsiness Detection, Alertness Monitoring.

A purchaser's optimal procurement strategy under emergencies

This paper investigates a purchaser's optimal procurement strategy under emergencies. The occurrence of emergencies often leads to sharp fluctuations in prices and weakens supply stability, which increases procurement risks for purchasers. In this study, we use the option contract to actively respond to market fluctuations and reduce procurement risks caused by emergencies. If there is insufficient inventory due to occurrence of emergencies, part or all of the shortages can be met by an emergency replenishment. Then, we conduct an in-depth research on the optimal option procurement strategy for purchasers under emergencies. The results show that, a higher emergency replenishment rate leads to a smaller option purchase quantity if the shortage cost is not considered, since the emergency replenishment can save part or all of the shortages. If the shortage cost is considered, both over-purchasing and under-purchasing of options lead to corresponding losses, and then the trend in a purchaser's optimal option purchasing decision is decided by the dominance of the two types of losses. Finally, we summarize the results of the study to give managerial insights into the optimal option purchasing strategies for purchasers under emergencies.

Pilot–scale vertical continuous–flow reactors applied to treat rural domestic wastewater at low temperature via aerobic granular sludge

A pilot–scale vertical–flow continuous flow reactors (VF–CFR) was investigated for the treatment of rural domestic wastewater in the cold areas of Northeast China. VF–CFR helps in the creating of aerobic granular sludge (AGS), which improves the sludge concentration and removal efficiency of pollutants. VF–CFR achieved a high removal efficiency of Chemical Oxygen Demand (COD), Ammonia Nitrogen (NH3−N), Total Nitrogen (TN) and Total Phosphorus (TP) with 90 %, 94 %, 75 % and 93 % under the condition of sharp fluctuation of influent quality and temperature. The high–throughput sequencing analysis of the AGS revealed that Flavobacterium was a functional bacterium in the AGS process that had the function of heterotrophic nitrification and denitrification. The field–scale experiment confirmed the superiority of VF–CFR in wastewater treatment efficacy and stability. During the experiment, the concentrations of COD, TP and NH3–N in effluent at different temperatures were well met with the first–class A discharge standard of China (GB 18596–2001). However, there was a risk of exceedance exists in the reduction of TN removal under low temperature conditions.