Sudden Increase In Temperature Research Articles

Recycling of waste tires to crude pyrolytic oil: Engine performance, combustion characteristics and emissions analysis of diesel-butanol-crude pyrolytic oil blends in CI diesel engines

In this study, crude pyrolytic oil (CPO) was blended with fossil diesel and butanol in different ratios. Following this strategy, engine performance, combustion characteristics and emissions analyses were experimentally examined in a CI diesel engine. Experiments were carried out with 7 blends at 1500 and 2000 rpm and 5 engine loads (0–12.5–25–37.5–50 Nm). Additionally, 1 % (by volume) cetane number improver was added to all blends except for D100 and PO50 in order to improve combustion. The main findings showed that even at 50 % blends of CPO, the engine still ran smoothly without causing any knocking in the engine. The highest BSFC was recorded with PO30Bu20CN1 with 425.35 g/kWh at 12.5 Nm load at 2000 rpm. On average, the lowest BTE was observed with PO30Bu20CN1 with an average reduction of 8.28 % compared to D100 at 1500. At all loads and engine speeds, ignition delay (ID) was prolonged and this caused a sudden increase in pressure and temperature in the cylinder for PO50 causing the highest NOx formation. The Pmax was achieved with PO50 fuel (64.19 bar at 25 Nm and 2000 rpm). This study supports the efforts to recycle waste tire. The study recommends further investigation of such developed alternative fuels.

Assessment of the effect of evaporation on the hydrological regime of the water reservoir

During the review of the effect of evaporation on the change of the hydrological regime of water reservoirs, an analysis was carried out on how global climate change will lead to a change in the water reservoir regime. Taking into account the sudden increase in air temperature and the effect of wind, the evaporation process in the month of June (June) was studied simultaneously during the years 2018 and 2022. During the research period, the effect of evaporation on the change of the hydrological regime of the water reservoir was determined by empirical formulas proposed by scientists such as B. D. Zaykov, A. Z. Braslavsky and P. A. Vikulina, and it was observed that the evaporation process is increasing year by year. According to accurate calculation books, the evaporation in June 2018 at the same time E0=86.14 mm, Ev=108.16 mm, in June 2022 this figure is E0=121.27 mm, Ev=166.35 mm was found to be organizing. According to the analysis, we can see that the evaporation process in the reservoirs is increasing year by year, which causes a change in the hydrological regime of the reservoirs. The evaporation process is mainly caused by the increase in air temperature, the influence of the wind, and the fact that the surface of the reservoir is at its maximum level in May and June.

Experimental investigations on the growth of wall-attached bubble in total dissolved gas supersaturated water.

Due to dam discharge, waterfalls, sudden increases in water temperature and oxygen production by photosynthesis, the total dissolved gas (TDG) in water is often supersaturated, which may have serious effects on aquatic ecology. When the atmospheric pressure is lower than the TDG pressure in water, the supersaturated dissolved gas in water will slowly release into air. Wall-attached bubbles were formed during the TDG release process. The generation and departure of wall-attached bubbles influence the release process of TDG in water. To simulate the growth period of the wall-attached bubbles under different pressures, a decompression experimental device was designed to record the supersaturated TDG release process. Based on experimental data and mathematical calculations, the quantitative relationship between the bubble growth rate and environmental pressure was obtained. The supersaturated TDG dissipation rate increases monotonically with increasing relative vacuum degree. Applied the calculation method about the wall-attached bubble growth rate, a formula of the supersaturated TDG adsorption flux was proposed, and a prediction method of the TDG release coefficient was established. The simulation results show that with the increasing relative vacuum degree, the TDG release coefficient increases correspondingly, and the adsorption from wall surface area can be obviously promoted. This study provides an important theoretical basis for the accurate calculation of the TDG release process and provides a scientific basis for the accurate prediction of the spatial and temporal distribution of supersaturated TDG under different pressure and solid wall conditions.

Modeling snowmelt influence on shallow landslides in Tartano valley, Italian Alps

Shallow landslides (SLs) are rapid soil mass movements, typically occurring in the mountain areas, involving the most superficial soil layers up to 5 to 10 m in depth. Damages, and casualties due to shallow landslides are recorded globally, and in literature a variety of models to study landslides have been implemented hitherto. Often times, shallow landslides occur in the wake of snowfall events, when sudden temperature increase triggers fast snow thaw, and soil moisture increases thereby. Several models studied the influence of intensity, and duration of rainfall upon shallow landslides, but the effect of snow melt in spring/summer was little considered so far. Thus, we developed a simple but robust, and parameter-wise parsimonious model, that mimics the triggering mechanism of SLs, accounting for the combined effect of precipitation duration and intensity, and snowmelt at thaw. The model is here applied to the case study of the high altitude Tartano basin, paradigmatic of SLs in the Alps of Lombardia. Our results showed that about 26 % of the Tartano basin slopes display unstable conditions. Using a traditional (i.e. rainfall-based) approach, the occurrence of shallow landslides was predicted in ca. 19 % of the basin, mainly during storms in October and November. In contrast, when snowmelt was included, the model was able to mimic potential SLs even during April and May, when snow melt rate is the highest, and may increase SLs triggering potential, to ca. 26 % of the treated area. With better spatial and temporal description of slope failure as achieved here, validated against observed failures, a public authority may be prepared to implement emergency plans, to prevent injuries, causalities, and damages to infrastructures even during springtime, when shallow landslides may occur in response to fast snowmelt, even during dry, clear sky days, and with scarce/null precipitation.

A Numerical Study of the behaviour on Lock Volume Variations in Lock-Exchange Density Current in Cold Fresh Water

The behaviour of warm discharge through lock-exchange was investigated numerically, with the assumption that density was taken as a quadratic function of temperature. Simulations were conducted eleven different times varying barrier position. This work as presented here is practical and can also enhance policy making towards the protection of the aquatic ecosystems. Such behaviours are evident in lakes, especially in holomictic lakes and warm discharge from thermoelectric power generating plants. The sudden increase in water temperature after discharge may leads to ”thermal shock” killing aquatic life that has become acclimatised to living in a stable temperate environment. The aim of this investigation is to better fathom and as well, gain more insight into such flows. The results show that regimes of flow is dependent on the size of the lock volume. The general behaviours here are dependent on lock volume, density difference and Reynolds number. Effects of back reflected waves on the propagation speed was not significant for small lock volume simulations. A rapid collapsing behaviour of fluid was noticed for simulations with small lock volume, and the velocity decreases with increase in lock volume in this same phase. Propagation speed is not totally independent of the lock volume. Cabbeling was also key at the point where water masses meet, and as well the development of Kelvin-Helmholtz instabilities. Relations that describes the various regimes of flow are given in Table (1 - 11). Though, there are little variations in the scaling laws as compared to the earlier studied cases where density difference was by the means of salt water. Lastly, it will be interesting if measures can be taken to eliminate the effect of this back reflected waves in other to properly fathom the behaviour in thepropagation of the frontal speed after the slumping phase.

Rub-impact behaviors of a multistage bladed drum rotor under high time-varying temperature

In a gas turbine, the multistage bladed drum rotor often operates under high time-varying ambient temperature. Thermal deformations of the thin drum could lead to the rub-impact fault between multistage blade rows and the outer casing, which may cause damage to the blades or even the whole machine. Due to the complexity of the thermoelastic coupling solution, rub-impact characteristics of this kind of rotor system are not clear. This study develops a multistage bladed drum rotor model with the rub-impact fault induced by high time-varying temperature. A solution process for the thermoelastic dynamics analysis of the multistage bladed drum rotor system is proposed, combining experimental, numerical, and analytical methods. According to temperature characteristics in a gas turbine, the effect of the high-temperature environment, heating, fluctuating temperature rise, and cooling on the rub-impact fault is the main emphasis of the study. The high-temperature environment could cause a rub-impact fault for the multistage bladed drum rotor. The sudden increase of the exhaust temperature leads to paroxysmal vibrations, which could induce tip rub or make a slight rub-impact fault into a severe accident. Large fluctuation during temperature rise induces the rub-impact fault and even leads to the continuous aggravation of the rub-impact fault. Fortunately, reducing an appropriate exhaust temperature can eliminate or weaken the rub-impact fault and avoid shock vibrations induced by the sudden drop of the high ambient temperature at the same time. Besides, more blade rows could aggravate this kind of rub-impact phenomenon for the multistage bladed drum rotor.

The success of the bloom-forming cyanobacteria Planktothrix: Genotypes variability supports variable responses to light and temperature stress

Cyanobacterial blooms can modify the dynamic of aquatic ecosystems and have harmful consequences for human activities. Moreover, cyanobacteria can produce a variety of cyanotoxins, including microcystins, but little is known about the role of environmental factors on the prevalence of microcystin producers in the cyanobacterial bloom dynamics. This study aimed to better understand the success of Planktothrix in various environments by unveiling the variety of strategies governing cell responses to sudden changes in light intensity and temperature. The cellular responses (photosynthesis, photoprotection, heat shock response and metabolites synthesis) of four Planktothrix strains to high-light or high-temperature were studied, focusing on how distinct ecotypes (red- or green-pigmented) and microcystin production capability affect cyanobacteria's ability to cope with such abiotic stimuli. Our results showed that high-light and high-temperature impact different cellular processes and that Planktothrix responses are heterogeneous, specific to each strain and thus, to genotype. The ability of cyanobacteria to cope with sudden increase in light intensity and temperature was not related to red- or green-pigmented ecotype or microcystin production capability. According to our results, microcystin producers do not cope better to high-light or high-temperature and microcystin content does not increase in response to such stresses.

Numerical study on flow and heat transfer of S−CO2 in inclined tubes under different flow conditions

In this paper, the numerical simulation of supercritical carbon dioxide ( S − CO 2 ) flowing in large diameter inclined circular tubes with different heat flux and inlet temperature is studied. According to the experimental results of S − CO 2 flow in a horizontal tube, the S S T k − ω model was found to be the most accurate predictor of heat transfer. Based on the phase transition temperature of the pseudo-boiling phenomenon under subcritical conditions, a gas-like film radius model was established. The results show that when heat flux is too large, the wall temperature rises quickly, which makes the density gradient in the cross-section, buoyancy and gas-like film radius increase constantly, resulting in the gathering of a large number of low-density and poor heat transfer performances at the top generatrix, causing a sudden increase in wall temperature and the heat transfer coefficient decrease significantly. As the inlet temperature increases, buoyancy and relative secondary flow energy decreases and the fluid temperature rises dramatically, eventually leading to a rapid decrease in thermal conductivity and heat transfer capacity.

Experimental Radial Profiles of Early Time (<4 μs) Neutral and Ion Spectroscopic Signatures in Lightning‐Like Discharges

AbstractThis study presents experimental results for the radial and temporal variation of neutral and ion spectroscopic signatures emerging from the heated channel of lightning‐like discharges diagnosed with a high speed (900,000 fps) imaging spectrograph. Light emissions emanate from three regions: an inner core (up to ∼2 mm), an external sheath (up to ∼4 mm) featuring a sudden temperature increase, and further optical emissions forming a dim glow from 4 mm up to 16 mm. The optical emissions are initially (<1.11 μs) dominated by the N2 first positive system at 660.8 nm and by the N II ion line at 661.05 nm. Between 1.11 and 3.33 μs the optical emissions are dominated by Hα (656.3 nm) and O II ion (656.54 nm) lines. The N II ion line at 648.20 nm prevails in the outer dim glow region (9–12 mm) before 2.22 μs. Spectroscopic signals were used to experimentally derive the time dynamics of the electron density and electron/gas temperature radial profiles, which allowed the estimation of the early time overpressure pulse, electrical conductivity and concentrations of key molecular species (N2, NO, O2, OH, H2, N2O, NO2, HO2, O3, and H2O) along the radial axis of the heated air plasma channel. These populations were calculated from the overpressure pulse, assuming that they were produced from humid (50%) air under thermal equilibrium conditions. OH is found to be the second most abundant molecular species (after NO) directly generated by heated lightning‐like channels.

32Pi Labeled Transgenic Wheat Shows the Accumulation of Phosphatidylinositol 4,5-bisphosphate and Phosphatidic Acid Under Heat and Osmotic Stress.

The ensuing heat stress drastically affects wheat plant growth and development, consequently compromising its grain yield. There are many thermoregulatory processes/mechanisms mediated by ion channels, lipids, and lipid-modifying enzymes that occur in the plasma membrane and the chloroplast. With the onset of abiotic or biotic stresses, phosphoinositide-specific phospholipase C (PI-PLC), as a signaling enzyme, hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) to generate inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) which is further phosphorylated into phosphatidic acid (PA) as a secondary messenger and is involved in multiple processes. In the current study, a phospholipase C (PLC) signaling pathway was investigated in spring wheat (Triticum aestivum L.) and evaluated its four AtPLC5 overexpressed (OE)/transgenic lines under heat and osmotic stresses through 32Pi radioactive labeling. Naturally, the wheat harbors only a small amount of PIP2. However, with the sudden increase in temperature (40°C), PIP2 levels start to rise within 7.5 min in a time-dependent manner in wild-type (Wt) wheat. While the Phosphatidic acid (PA) level also elevated up to 1.6-fold upon exposing wild-type wheat to heat stress (40°C). However, at the anthesis stage, a significant increase of ∼4.5-folds in PIP2 level was observed within 30 min at 40°C in AtPLC5 over-expressed wheat lines. Significant differences in PIP2 level were observed in Wt and AtPLC5-OE lines when treated with 1200 mM sorbitol solution. It is assumed that the phenomenon might be a result of the activation of PLC/DGK pathways. Together, these results indicate that heat stress and osmotic stress activate several lipid responses in wild-type and transgenic wheat and can explain heat and osmotic stress tolerance in the wheat plant.

Experimental study of the growth period of wall-attached bubbles

Abstract Due to dam discharge, waterfalls, sudden increases in water temperature and oxygen production by photosynthesis, the total dissolved gas (TDG) in water is often supersaturated, which may have serious effects on aquatic ecology. Wall-attached bubbles formed during the TDG release process and the generation and departure of wall-attached bubbles influenced the release of TDG from water. Therefore, an experiment was performed to simulate the growth of wall-attached bubbles at various water flow velocities, a quantitative relationship between the wall-attached bubble growth period and flow velocity was obtained. Another quantitative relationship, between the wall-attached bubble departure diameter and turbulent kinetic energy of flowing water, was also determined. The analysis results of the TDG release rate proved that the adsorption of TDG on solid walls was considerably affected by flow velocity. The analysis models the TDG release mechanism through complex experiments and provides a method to better identify sites for supersaturated TDG adsorption. This study serves as an important theoretical basis for revealing the mechanism by which solid surfaces promote the release process of supersaturated TDG in natural water.

Thermal Acclimation and Adaptation in Marine Protozooplankton and Mixoplankton.

Proper thermal adaptation is key to understanding how species respond to long-term changes in temperature. However, this is seldom considered in protozooplankton and mixoplankton experiments. In this work, we studied how two heterotrophic dinoflagellates (Gyrodinium dominans and Oxyrrhis marina), one heterotrophic ciliate (Strombidium arenicola), and one mixotrophic dinoflagellate (Karlodinium armiger) responded to warming. To do so, we compared strains adapted at 16, 19, and 22°C and those adapted at 16°C and exposed for 3 days to temperature increases of 3 and 6°C (acclimated treatments). Neither their carbon, nitrogen or phosphorus (CNP) contents nor their corresponding elemental ratios showed straightforward changes with temperature, except for a modest increase in P contents with temperature in some grazers. In general, the performance of both acclimated and adapted grazers increased from 16 to 19°C and then dropped at 22°C, with a few exceptions. Therefore, our organisms followed the “hotter is better” hypothesis for a temperature rise of 3°C; an increase of >6°C, however, resulted in variable outcomes. Despite the disparity in responses among species and physiological rates, 19°C-adapted organisms, in general, performed better than acclimated-only (16°C-adapted organisms incubated at +3°C). However, at 22°C, most species were at the limit of their metabolic equilibrium and were unable to fully adapt. Nevertheless, adaptation to higher temperatures allowed strains to maintain physiological activities when exposed to sudden increases in temperature (up to 25°C). In summary, adaptation to temperature seems to confer a selective advantage to protistan grazers within a narrow range (i.e., ca. 3°C). Adaptation to much higher increases of temperatures (i.e., +6°C) does not confer any clear physiological advantage (with few exceptions; e.g., the mixotroph K. armiger), at least within the time frame of our experiments.

Effect of Elevated Temperature on the Microstructure of Metakaolin-Based Geopolymer.

Currently, geopolymer is being considered as a future oil-well cement. For wellbore applications, geopolymers are initially tested at specific temperature conditions. However, an oil-wellbore may experience a sudden increase in temperature which may adversely affect geopolymer systems designed for low to moderate temperature conditions. In this work, the effect of elevated temperatures on the microstructure of the geopolymer was simulated. Metakaolin-based geopolymer systems cured at 163 °F for 48 h were subjected to a temperature ramp of 194 °F and 248 °F for 24 h. X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetry analysis techniques were used to study the microstructural changes. The analytical techniques show the formation of new crystalline phases when the geopolymer cured at 163 °F was suddenly exposed to higher temperatures. These crystalline phases, for instance, gobbinsite and anorthite, observed in the microstructure have the potential to cause thermal stress, weaken the system, and ultimately affect the geopolymer’s ability to effectively isolate the formation and support the casing.

Investigating the impact of indoor temperature on the performance of the retail commercial refrigeration system

Commercial food outlets in the UK are responsible for 3% of the UK total energy consumption, with refrigeration systems account for 29% of this total. In this paper, a validated model that simulates a commercial refrigeration system installed over 2000 sq. ft to mimic a real express store installed at the Riseholme Refrigeration Research Centre at the University of Lincoln, UK, is presented. Investigations are conducted to examine the different failures of air conditioning (AC) systems and their impacts on the indoor store temperature, and hence on the refrigeration performance and energy consumption. Three different scenarios were examined: gradual increase in store temperature caused by an AC system with reduced performance, sudden increase in store temperature caused by a drastic AC failure and fluctuations in store temperature caused by a faulty AC system. The results of the investigation for different failure scenarios of the AC system during 3 h of continual operation showed an increase in the energy consumption of the refrigeration system by 17.4% as a result of gradual AC failure, 33.6% for the sudden failure and 5.3% for the intermittent failure. It is concluded that the AC failures caused the power drawn to increase due to spending a prolonged period of time at higher temperatures than during the normal AC operation. Also, the frequency which the compressors switch on and off increases the level of wear on the compressors. Both gradual and sudden failures of the AC system show a sustained increase in temperature that leads to a greater duty cycle for the expansion valve to increase the amount of refrigerant available. It is found that the sudden failure of the AC system had the greatest impact on the system, as the temperature of the store rises quickest, the display cases are exposed to higher temperatures for a longer time; this causes the greatest demand on the system and so lead to the largest power consumption. It is notable that for all three failure types that the product temperature experiences, there are no noticeable fluctuations and they remain comfortably within the temperature boundaries between 3 and 1 °C, as the system is able to provide an adequate cooling.

Explosive boiling of liquid nitrogen in a long thin tube and its application to the detection of a local temperature rise

To promote the commercial use of high-temperature superconducting devices, the ability to detect temperature anomalies easily and reliably and thereby protect the devices is important. In particular, a sudden local temperature increase due to a superconducting-to-normal transition can damage a device. In the present study, we propose a method to detect explosive boiling of superheated liquid nitrogen sealed in a long thin tube using a pressure gauge connected to the end of the tube. Experiments using a stainless-steel tube with an inner diameter of 1 mm and a maximum length of 50 m under various conditions showed that the local temperature rise caused explosive boiling at a temperature slightly below the superheat limit of 110 K for liquid nitrogen; the results also showed that the rapid pressure increase was transmitted to the end of the tube at approximately the speed of sound (∼830 m/s). The proposed method of placing a thin tube along high-temperature superconducting conductors or cryogenic structures can be used to easily detect a local temperature rise.

Transcription factor BES1 interacts with HSFA1 to promote heat stress resistance of plants.

Heat stress is a major environmental stress type that can limit plant growth and development. To survive sudden temperature increases, plants utilize the heat shock response, an ancient signaling pathway. Initial results had suggested a role for brassinosteroids (BRs) in this response. Brassinosteroids are growth‐promoting steroid hormones whose activity is mediated by transcription factors of the BES1/BZR1 subfamily. Here, we provide evidence that BES1 can contribute to heat stress signaling. In response to heat, BES1 is activated even in the absence of BRs and directly binds to heat shock elements (HSEs), known binding sites of heat shock transcription factors (HSFs). HSFs of the HSFA1 type can interact with BES1 and facilitate its activity in HSE binding. These findings lead us to propose an extended model of the heat stress response in plants, in which the recruitment of BES1 is a means of heat stress signaling cross‐talk with a central growth regulatory pathway.

Thermomechanical analysis of a lead-cooled fast reactor with a fast-running model

The aim of this work is the development and testing of a simplified and fast-running model for thermomechanical analysis of a Lead-cooled Fast Reactor (LFR). For this work a fast-running mechanical model has been coupled with a heat transfer model previously developed, as part of AZTLAN-platform project. In a nuclear reactor, an optimal heat transfer in the fuel is needed to avoid unwanted phenomena related to sudden increases in temperature. One of the main mechanisms of deterioration of heat transfer in the fuel is the thermal expansion of the fuel and cladding since it leads to the narrowing or even blockage of the space between them causing thermal and mechanical loads that can produce fuel failure. Here, the results of the numerical calculation for stress, deformation, and radial displacement in the fuel of an LFR are presented as a function of the temperature. The simplified model was validated with a Finite Element Method peridynamics model getting consistent results.

Kinetic and Thermodynamic Analysis of High-Pressure CO2 Capture Using Ethylenediamine: Experimental Study and Modeling

One of the alternatives to reduce CO2 emissions from industrial sources (mainly the oil and gas industry) is CO2 capture. Absorption with chemical solvents (alkanolamines in aqueous solutions) is the most widely used conventional technology for CO2 capture. Despite the competitive advantages of chemical solvents, the technological challenge in improving the absorption process is to apply alternative solvents, reducing energy demand and increasing the CO2 captured per unit of solvent mass. This work presents an experimental study related to the kinetic and thermodynamic analysis of high-pressure CO2 capture using ethylenediamine (EDA) as a chemical solvent. EDA has two amine groups that can increase the CO2 capture capacity per unit of solvent. A non-stirred experimental setup was installed and commissioned for CO2 capture testing. Tests of the solubility of CO2 in water were carried out to validate the experimental setup. CO2 capture testing was accomplished using EDA in aqueous solutions (0, 5, 10, and 20 wt.% in amine). Finally, a kinetic model involving two steps was proposed, including a rapid absorption step and a slow diffusion step. EDA accelerated the CO2 capture performance. Sudden temperature increases were observed during the initial minutes. The CO2 capture was triggered after the absorption of a minimal amount of CO2 (~10 mmol) into the liquid solutions, and could correspond to the “lean amine acid gas loading” in a typical sweetening process using alkanolamines. At equilibrium, there was a linear relationship between the CO2 loading and the EDA concentration. The CO2 capture behavior obtained adapts accurately (AAD < 1%) to the kinetic mechanism.

Overexpression of seagrass DnaJ gene ZjDjB1 enhances the thermotolerance of transgenic arabidopsis thaliana.

Seagrass meadows are one of the most important marine resources that grow along the coast. They provide habitat and a food source for animals. They also protect the coast, fix sediment and purify seawater. In the current period of global climate change, anomalies in coastal water temperatures are increasing. A sudden increase in water temperature owing to a heat wave can have a profound effect on seagrass. Zostera japonica is a type of intertidal seagrasses, which is exposed to the air at low tide. High temperatures in the summer often lead to a decline in seagrass meadows. DnaJ proteins, also known as J proteins, are a family of conserved chaperone proteins. They are designated as J proteins because they contain a highly conserved J domain. They function as chaperones of heat shock proteins in organisms. In this study, the role of DnaJ protein (ZjDjB1) of Z. japonica under heat stress was studied. ZjDjB1 was localized to the cytoplasm and nucleus. The overexpression of ZjDjB1 in Arabidopsis thaliana results in an increase in thermotolerance and a decrease in the accumulation of reactive oxygen species and also a reduction in membrane damage. ZjDjB1 may achieve this goal by maintaining a low activity of proteolytic enzymes.

Tropical-based EBPR process: The long-term stability, microbial community and its response towards temperature stress.

Temperature is known to influence the operational efficiency of enhanced biological phosphorus removal (EBPR) systems. This study investigated the impact of thermal stress above 30°C on the properties of an EBPR community established with tropical inoculum. The results confirmed the stability of the 30°C EBPR system with high P-removal efficiency over 210 days. Accumulibacter was abundant in the community. When the EBPR sludge was subjected to a sudden temperature increase to 35°C under multiple cycles of anaerobic-aerobic phases, each lasting 4h, high P-removal was maintained over 2days, before gradually failing when the Competibacter appeared to outcompete Accumulibacter. These data suggested that the EBPR capacity is robust when subjected to occasional thermal stress. However, it could not be maintained even for a short time under temperature stress at 40°C. Thus, the threshold temperature for tropical EBPR failure is between 35°C and 40°C. PRACTITIONER POINTS: EBPR was stably maintained at 30°C with Accumulibacter being dominant. Good EBPR activities persisted for a short period at 35°C. EBPR was deteriorated at 40°C. The threshold temperature for tropical EBPR failure is between 35°C and 40°C.