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A multi-strain yeast-based paraprobiotic (MsYbP) comprising inactive cells and polysaccharides (β-glucan, mannan oligosaccharides, and oligosaccharides) derived from Saccharomyces cerevisiae and Cyberlindnera jadinii could ensure optimal growth and health in farmed fish. This study assessed the impact of an MsYbP on the growth, immune responses, antioxidant capacities, and liver health of largemouth bass (Micropterus salmoides) through lab-scale (65 days) and pilot-scale (15 weeks) experiments. Two groups of fish were monitored: one fed a control diet without the MsYbP and another fed 0.08% and 0.1% MsYbP in the lab-scale and pilot-scale studies, respectively (referred to as YANG). In the lab-scale study, four replicates were conducted, with 20 fish per replicate (average initial body weight = 31.0 ± 0.8 g), while the pilot-scale study involved three replicates with approximately 1500 fish per replicate (average initial body weight = 80.0 ± 2.2 g). The results indicate that the MsYbP-fed fish exhibited a significant increase in growth in both studies (p < 0.05). Additionally, the dietary MsYbP led to a noteworthy reduction in the liver function parameters (p < 0.05), such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (AKP), and hepatic nuclear density, indicating improved liver health. Furthermore, the dietary MsYbP elevated the antioxidative capacity of the fish by reducing their malondialdehyde levels and increasing their levels and gene expressions related to antioxidative markers, such as total antioxidant ca-pacity (T-AOC), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), catalase (CAT), nuclear factor erythroid 2-related factor 2 (nrf2) and kelch-1ike ech-associated protein (keap1) in both studies (p < 0.05). In terms of hepatic immune responses, the lab-scale study showed an increase in inflammation-related gene expressions, such as interleukin-1β (il-1β) and transforming growth factor β1 (tgf-β1), while the pilot-scale study significantly suppressed the expressions of genes related to inflammatory responses, such as tumor necrosis factor α (tnfα) and interleukin-10 (il-10) (p < 0.05). In summary, our findings underscore the role of dietary multi-strain yeast-based paraprobiotics in enhancing the growth and liver health of largemouth bass, potentially through increased antioxidative capacity and the modulation of immune responses, emphasizing the significance of employing yeast-based paraprobiotics in commercial conditions. [ABSTRACT FROM AUTHOR]

A multi-strain yeast-based paraprobiotic (MsYbP) comprising inactive cells and polysaccharides (β-glucan, mannan oligosaccharides, and oligosaccharides) derived from Saccharomyces cerevisiae and Cyberlindnera jadinii could ensure optimal growth and health in farmed fish. This study assessed the impact of an MsYbP on the growth, immune responses, antioxidant capacities, and liver health of largemouth bass (Micropterus salmoides) through lab-scale (65 days) and pilot-scale (15 weeks) experiments. Two groups of fish were monitored: one fed a control diet without the MsYbP and another fed 0.08% and 0.1% MsYbP in the lab-scale and pilot-scale studies, respectively (referred to as YANG). In the lab-scale study, four replicates were conducted, with 20 fish per replicate (average initial body weight = 31.0 ± 0.8 g), while the pilot-scale study involved three replicates with approximately 1500 fish per replicate (average initial body weight = 80.0 ± 2.2 g). The results indicate that the MsYbP-fed fish exhibited a significant increase in growth in both studies (p < 0.05). Additionally, the dietary MsYbP led to a noteworthy reduction in the liver function parameters (p < 0.05), such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (AKP), and hepatic nuclear density, indicating improved liver health. Furthermore, the dietary MsYbP elevated the antioxidative capacity of the fish by reducing their malondialdehyde levels and increasing their levels and gene expressions related to antioxidative markers, such as total antioxidant ca-pacity (T-AOC), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), catalase (CAT), nuclear factor erythroid 2-related factor 2 (nrf2) and kelch-1ike ech-associated protein (keap1) in both studies (p < 0.05). In terms of hepatic immune responses, the lab-scale study showed an increase in inflammation-related gene expressions, such as interleukin-1β (il-1β) and transforming growth factor β1 (tgf-β1), while the pilot-scale study significantly suppressed the expressions of genes related to inflammatory responses, such as tumor necrosis factor α (tnfα) and interleukin-10 (il-10) (p < 0.05). In summary, our findings underscore the role of dietary multi-strain yeast-based paraprobiotics in enhancing the growth and liver health of largemouth bass, potentially through increased antioxidative capacity and the modulation of immune responses, emphasizing the significance of employing yeast-based paraprobiotics in commercial conditions.

One-dimensional modeling of the hydrodynamic river networks of plain urban rivers has been employed to optimize operating regulations in these river networks. However, pilot-scale experiments are still lacking for the validation of hydrodynamics obtained by modeling to improve water quality. In this study, a pilot-scale experiment combined with theoretical calculation was conducted to determine both the hydrodynamics and water quality in the Hutang area of Changzhou, China. The simulation results showed that using high-performance pumps on the border to drain the river beyond it could increase the frequency of water replenishment. The results of the pilot-scale experiment are consistent with the simulation. Moreover, only in condition (c) does the water of the Wuyi canal flow into the Wunan river. With the exception of turbidity, the highest number of rivers with improved water quality tables occurred in this condition. Based on the response mechanism between the flow rate and the water quality, a flow rate within the range of 0.12 m/s to 0.28 m/s can help reduce comprehensive pollution. This study successfully enhanced the hydrodynamic regulation and water quality of the rivers in the Hutang region using technologies combined with simulation and pilot-scale experiments. [ABSTRACT FROM AUTHOR]

• Impacts of nitrate recharge on the organic pollutants' attenuation were investigated. • Pristine groundwater ecosystem exhibits limited resistance to organic contamination. • Nitrate recharge increases the degradation of pollutants by >4 times. • Nitrate is more readily available in anaerobic biodegradation. • Nitrate oxidation of sulfides for sulfate recovery and aquifer toxicity reduction. Anaerobic biodegradation plays a crucial role in attenuating organic contaminants in natural aquifers, where the concentration and type of electron acceptors directly determine the stages and rates of degradation progress. In this study, nitrate depletion was monitored in a simulated pilot-scale aquifer contaminated with toluene and trichloroethylene, while sulfate became the new periodic electron acceptor, accompanied by a decrease in the contaminant attenuation rate. Consequently, nitrate was injected into the contaminated plume in stages, and the hydro- and biochemical impacts were further monitored. The results revealed that the active recharge of nitrate became a new electron donor involved in anaerobic reduction processes, with contaminants attenuation rates increased by 2.48–3.88 times compared with that before injection. Moreover, the active recharge of nitrate inhibited further consumption of sulfate and oxidized pre-existing sulfides, which reduced the biological toxicity of the aquatic environment and provided favorable conditions for the growth of nitrate-reducing microorganisms. This study evaluated the enhancement of natural attenuation by recharging nitrate as an electron acceptor, providing a theoretical basis for environmentally friendly and economic remediation of petroleum-contaminated aquifers. [Display omitted] [ABSTRACT FROM AUTHOR]

With the development of the steel industry, the use of high-grade and easy-to-handle iron ore is gradually decreasing. At present, the effective utilization of low-grade and refractory iron ore, particularly high-phosphorus oolitic iron ore, has gradually become a research hotspot and a worldwide problem. This type of ore is mainly distributed in the USA, France, Germany, Russia, and China and often has an oolitic structure, where the intercalation relationship between iron minerals and gangue minerals is complicated and the phosphorus content is high. Therefore, this type of ore has not yet been developed and utilized. Studies have shown that the use of coal-based direct reduction–magnetic separation to process high-phosphorus oolitic iron ore is one of the methods to achieve efficient utilization of its iron resources. Researchers have conducted in-depth studies on process optimization, dephosphorization mechanism, and iron and phosphorus reduction kinetics. To determine the parameters for the industrial test of the rotary kiln, based on the best result of the small-scale test, a pilot-scale experiment on iron recovery and dephosphorization from high-phosphorus oolitic iron ore was conducted using coal-based direct reduction, followed by magnetic separation. Results showed that under the optimum conditions, the grade and recovery of iron and phosphorus contents in the powdered reduced iron concentrate were 94.17%, 77.47%, and 0.08%, respectively. Limestone dosage of 28%, anthracite dosage of 16%, reduction temperature of 1300 °C and reduction time of 3 h were recommended as the initial conditions for the industrial test of the rotary kiln. The mechanisms of anthracite were investigated by X-ray diffraction and scanning electron microscopy–energy-dispersive X-ray spectroscopy. The results showed that with the increase in anthracite dosage, the reduction of wustite and pleonaste and the growth of iron particles are promoted, thereby improving the recovery effect of iron. However, a high anthracite dosage enhanced the reducing atmosphere and its ash content consumed limestone, causing phosphorus in iron minerals and apatite to be reduced to elemental phosphorus and iron particles to form the iron–phosphorus alloy.

In recent years, the technology of storing and transporting natural gas in the form of hydrate has received a lot of attention. At present, the research on the synthesis of natural gas hydrate for the purpose of storage and transportation is still in the laboratory stage, and its synthesis process is in the design and conception stage. The influencing factors of natural gas hydrate synthesis under pilot-scale conditions are more complex. Moreover, pilot experiments are oriented to actual production, and its economic feasibility and operational convenience have higher requirements. This paper aimed to study the influencing factors of gas hydrate synthesis by spray method under pilot-scale conditions. Under specific conditions of surfactant and pressure, we carried out research on the effects of reaction temperature, different forms of atomizers, high-pressure pump flow, experimental water, and other factors. Experiments show that the optimal synthesis conditions were a temperature of −5 °C, a pressure of 5 MPa, a conical nozzle, a generated gas hydrate as the hydrate of type I structure, and a gas storage capacity of 1:123 (gas–water ratio). [ABSTRACT FROM AUTHOR]

Abstract A large share of the primary energy is consumed to provide space heating. Geothermal energy offers a regenerative alternative. For reasons of efficiency and environmental protection, it is important to ensure the system integrity of a borehole heat exchanger (BHE). Previous investigations have focused on the individual components of the BHE or on the grout and pipe systems’ integrity. This study focused on the analysis of the hydraulic system integrity of the complete subsoil–grout–pipe system as well as possible thermally induced changes. For this purpose, a pilot-scale experiment was built to test a 1-m section of a typical BHE under in situ pressure, hydraulic and temperature conditions. During the tests the hydraulic system permeability of the soil and the BHE was measured continuously and separately from each other. In addition, the temperature monitoring array was installed in a 50-cm cross-sectional area. Significant temperature-related fluctuations in the sealing performance could be observed. Hydraulic conductivity limits required by VDI 4640-2 (Thermal use of the underground—ground source heat pump systems, 2019) were exceeded without frost action. The succeeding application of freeze–thaw cycles further enhances the system permeability. The study shows that the thermally induced effects on the system integrity of the BHE are larger and more significant than the subsequent frost-induced effects. The hydrophobic character of the high-density polyethylene (PE-HD) pipes as well as its high coefficient of thermal expansion seem to be the main points of weakness in the system. Optimization research should focus on the interface connection between grout and pipe, whereby hydrophilic pipe materials such as stainless steel or aluminum should also be considered as well as manipulation of the pipe surface properties of PE-HD.

Chemical absorbents with low-energy requirements have become the primary focus of the research on CO2 capture from flue gas in power plants. To verify the absorption performance of the NICE absorbent developed by the National Institute of Clean-and-Low-Carbon Energy in China, a performance optimization test was conducted in Zhejiang University's pilot-scale platform, and the effects of the liquid–gas ratio, regeneration pressure, rich liquid fractional flow, and interstage cooling on the absorption performance and regeneration energy consumption were investigated. The results showed that in the CO2 pilot test, the optimized minimum regeneration energy consumption was 2.85 GJ/t CO2, and the corresponding process parameters were as follows: a liquid–gas ratio of 1.82 L/m3, regeneration pressure of 191 kPa, an interstage cooling temperature of 40 °C, and a rich liquid fractional flow ratio of 0.18. This study preliminarily verified the low-energy consumption performance of the NICE absorbent and showed its good potential for industrial applications. Additionally, the NICE absorbent showed promise for capital and operating cost savings because of its low liquid–gas ratio. [ABSTRACT FROM AUTHOR]

Sequential leaching and extraction of precious metals from high aluminum (Al) circulating fluidized bed (CFB) fly ash in China, which associated with lithium (Li) and gallium (Ga), is one of the most significant ways for value-added utilization. However, industrial application has been limited due to serious corrosion of equipment, significant energy consumption, and complex purification processes. To sufficiently leach valuable metals from CFB fly ash, a novel energy-efficient sulfuric acid (H2SO4) leaching process using dilution heat was developed, and the effects of iron (Fe) amount in the raw materials on the extraction process of Al, Li, and Ga as well as the as-prepared Al-based products were studied to efficiently obtain the qualified aluminum sulfate (Al2(SO4)3) products. The leaching behavior of each target element was systematically investigated by the laboratory and pilot-scale experiments. The extraction efficiencies for Al, Li, and Ga were 95.2%, 94.2%, and 87.7%, respectively, when the acid leaching process was conducted at the temperature of 140°C for 2 h, with the H2SO4 concentration of 40% and the solid-to-liquid ratio of 1/3, In the Pilot-scale experiment, the temperature of the reaction system can reach 120°C, 140°C, and 160°C by regulating the amount of H2SO4 added to release different heat, and efficient leaching of the target elements was achieved by the energy-efficient sulfuric acid leaching process. To obtain qualified Al2(SO4)3 products from fly ash, carbothermal reduction magnetic separation, and acid leaching were used for Fe removal from raw fly ash, and the Fe content in the as-prepared Al2(SO4)3 products was only 0.45% and 0.29%, which reached the standards of Class II qualified products and Class II first-grade products, respectively. This paper might provide an energy-efficient process for efficient and high-value utilization of solid waste fly ash. [ABSTRACT FROM AUTHOR]

A pilot-scale grinding technology of ceramic medium stirred mill was proposed in this study. Based on the specific productivity and grinding efficiency, the appropriate grinding parameters were ascertained as follows: material ball ratio of 0.7, ceramic ball medium size ratio (10 mm: 15 mm: 20 mm = 3:2:5), stirring speed of 110 rpm, grinding concentration of 50%, and medium filling rate of 90%. The stable running experiment was operated for 36 h at the optimum grinding parameters, and the iron concentrate grade 65.01% and iron recovery 89.29% were obtained after two stages magnetic separations when the content of −0.043 mm was 81.50%. Mineral liberation analyser (MLA) suggested that the liberation of iron from gangue was through grinding in the ceramic-medium stirred mill. Four NEUM-850 ceramic-medium stirred mills superseded the ball mills of second and third stage in the Aoshan concentrator, and the grinding unit consumption decreased by 48.38%. [Display omitted] • A pilot-scale grinding technology of ceramic medium stirring mill was proposed. • Stable running experiment was operated for 36 h to verify the equipment stability. • The high liberations of iron minerals and gangue minerals were obtained. • Four NEUM-850 mills were used to decrease the grinding unit consumption by 48.38%. [ABSTRACT FROM AUTHOR]

A large share of the primary energy is consumed to provide space heating. Geothermal energy offers a regenerative alternative. For reasons of efficiency and environmental protection, it is important to ensure the system integrity of a borehole heat exchanger (BHE). Previous investigations have focused on the individual components of the BHE or on the grout and pipe systems' integrity. This study focused on the analysis of the hydraulic system integrity of the complete subsoil–grout–pipe system as well as possible thermally induced changes. For this purpose, a pilot-scale experiment was built to test a 1-m section of a typical BHE under in situ pressure, hydraulic and temperature conditions. During the tests the hydraulic system permeability of the soil and the BHE was measured continuously and separately from each other. In addition, the temperature monitoring array was installed in a 50-cm cross-sectional area. Significant temperature-related fluctuations in the sealing performance could be observed. Hydraulic conductivity limits required by VDI 4640-2 (Thermal use of the underground—ground source heat pump systems, 2019) were exceeded without frost action. The succeeding application of freeze–thaw cycles further enhances the system permeability. The study shows that the thermally induced effects on the system integrity of the BHE are larger and more significant than the subsequent frost-induced effects. The hydrophobic character of the high-density polyethylene (PE-HD) pipes as well as its high coefficient of thermal expansion seem to be the main points of weakness in the system. Optimization research should focus on the interface connection between grout and pipe, whereby hydrophilic pipe materials such as stainless steel or aluminum should also be considered as well as manipulation of the pipe surface properties of PE-HD. [ABSTRACT FROM AUTHOR]

Anaerobic digestion is an effective biotechnological process for treatment of different agricultural, municipal and industrial wastes. Use of mathematical models is a powerful tool for investigations and optimisation of the anaerobic digestion. In this paper a simple mathematical model of the anaerobic digestion of wasted fruits and vegetables was developed and verified experimentally and by computer simulations using Simulink. A three-step mass-balance model was considered including the gas phase. The parameter identification was based on a set of 150 days of dynamical experiments in a laboratory bioreactor. Two step identification procedure to estimate 4 model parameters is presented. The results of 15 days of experiment in a pilot-scale bioreactor were then used to validate the model.

S-N inhibitors like thiourea and sewage sludge decomposition gases (SDG) are relatively novel dioxins suppressants and their efficiencies are proven in numerous lab-scale experiments. In this study, the suppression effects of both thiourea and SDG on the formation of dioxins are systematically tested in a pilot-scale system, situated at the bypass of a hazardous waste incinerator (HWI). Moreover, a flue gas recirculation system is used to get high dioxin suppression efficiencies. Operating experience shows that this system is capable of stable operation and to keep gaseous suppressant compounds at a high and desirable molar ratio (S + N)/Cl level in the flue gas. The suppression efficiencies of dioxins are investigated in flue gas both without and with addition of S-N inhibitors. A dioxin reduction of more than 80 % is already achieved when the (S + N)/Cl molar ratio is increased to ca. 2.20. When this (S + N)/Cl molar ratio has augmented to 4.18 by applying suppressant recirculation, the residual PCDD/Fs concentration in the flue gas shrank from 1.22 to 0.08 ng I-TEQ/Nm. Furthermore, the congener distribution of dioxins is analysed to find some possible explanation or suppression mechanism. In addition, a correlation analysis between (S + N)/Cl molar ratios and PCDD/Fs is also conducted to investigate the chief functional compounds for dioxin suppression. [ABSTRACT FROM AUTHOR]

The unsatisfactory performance of the conventional swine wastewater treatment is drawing increasing attention due to the large amount of refractory chemical oxygen demand (COD), nitrogen, and phosphorus attached to the suspended solids (SS). In this study, for the first time, a novel process based on bio-coagulation dewatering followed by a bio-oxidation (BDBO) system was developed to treat swine wastewater containing high-strength SS, COD, TN, and TP. Firstly, after the bio-coagulation process, the removal efficiencies of SS, COD, NH 3 -N, and TP reached as high as 99.94%, 98.09%, 61.19%, and 99.92%, respectively. Secondly, the filtrate of the bio-coagulation dewatering process was introduced into the subsequent bio-oxidation process, in which the residual COD and NH 3 -N were further biodegraded in a sequence batch reactor. In addition, the dewatering performance of the concentrated swine slurry was substantially improved, with the specific resistance to filtration decreasing from 17.0 × 10 12 to 0.3 × 10 12 m/kg. Moreover, the concentrated swine slurry was pressed and filtered into a semi-dry cake after pilot-scale bio-coagulation dewatering treatment. Finally, the concentrations of COD and NH 3 -N in the effluent after the BDBO process, ranging between 150-170 mg/L and 75-90 mg/L, met the relevant discharge standard. Compared to traditional treatments, the BDBO system has excellent large-scale potential for improving the treatment efficiency, shortening the operation period, and reducing the processing costs, and is emerging as a cost-effective alternative for the treatment of wastewater containing high concentrations of SS, COD, TN, and TP.

This study prepared fresh ferric hydroxide ( in-situ FeOxHy) by the enhanced hydrolysis of Fe3+ ions, and investigates its adsorptive behaviors toward Sb(III) and Sb(V) through laboratory and pilot-scale studies. A contact time of 120-min was enough to achieve adsorption equilibrium for Sb(III) and Sb(V) on the in-situ FeOxHy, and the Elovich model was best to describe the adsorption kinetics of Sb(III) and Sb(V). The Freundlich model was better than Langmuir model to describe the adsorption of Sb(III) and Sb(V) on the in-situ FeOxHy, and the maximum adsorption capacity of Sb(III) and Sb(V) was determined to be 12.77 and 10.21 mmol/g the in-situ FeOxHy as Fe, respectively. Adsorption of Sb(V) decreased whereas that of Sb(III) increased with elevated pH over pH 3-10, owing to the different electrical properties of Sb(III) and Sb(V). Adsorption of Sb(III) and Sb(V) was slightly affected by ionic strength, and thus indicated the formation of inner sphere complexes between Sb and the adsorbent. Sulfate and carbonate showed little effect on the adsorption of Sb(III) and Sb(V). Phosphate significantly inhibited the adsorption of Sb(V), whereas slightly effected that of Sb(III) due to its similar chemical structure to Sb(V). Pilot-scale continuous experiment indicated the feasibility of using in-situ FeOxHy to remove Sb(V), and equilibrium adsorption capacity at the equilibrium Sb(V) concentration of 10 μg/L was determined to be 0.11, 0.07, 0.07, 0.11, and 0.12 mg/g the in-situ FeOxHy as Fe at equilibrium pH of 7.5-7.7, 6.9-7.0, 6.3-6.6, 5.9-6.4, and 5.2-5.9, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sb-rich sludge char/leachate was co-treated via a novel in-situ recycling strategy. • LMCF characterisations and working mechanisms were scrutinized. • The performance of a pilot-scale pre-treatment system was evaluated. A novel in-situ recycling strategy is proposed for the co-disposal of antimony-rich dewatered sludge char (ADSC) and sludge leachate, and this strategy is further applied in a pilot-scale pre-treatment system. The preparation and operating conditions of lightweight micro-electrolysis ceramic fillers (LMCF) for ADSC were systematically studied, and LMCF characterisations and working mechanisms were scrutinised using SEM-mapping, XRD, XPS, EPR, BET, GF-AAS and CV examination. The results indicated that optimal preparation parameters for LMCF operation were 35% iron scrap content, a 1:2 vol ratio for Fe/ADSC, which was sintered at 900 ℃ for 2 h. Under the initial pH was 3.0 and the aerating intensity was 1 cm3·cm−2·s−1, the Sb-species were concentrated on the porous surface of the LMCF, degraded by various reactive oxygen species (ROS) released from Fe-C cells, and co-precipitated with FeOOH on the used LMCF surface. Thirty-one days of pilot-scale operations indicated that backwash was essential to maintain the LMCF with high efficiency regarding the total Sb removal and the biodegradability improvement of the actual sludge leachate. Lastly, preliminary economic assessment and suggestions for engineering-scale application were proposed. [ABSTRACT FROM AUTHOR]

Anaerobic digestion is an effective biotechnological process for treatment of different agricultural, municipal and industrial wastes. Use of mathematical models is a powerful tool for investigations and optimisation of the anaerobic digestion. In this paper a simple mathematical model of the anaerobic digestion of wasted fruits and vegetables was developed and verified experimentally and by computer simulations using Simulink. A three-step mass-balance model was considered including the gas phase. The parameter identification was based on a set of 150 days of dynamical experiments in a laboratory bioreactor. Two step identification procedure to estimate 4 model parameters is presented. The results of 15 days of experiment in a pilot-scale bioreactor were then used to validate the model. [ABSTRACT FROM AUTHOR]

Abstract: Trace element pollution of marine dredged sediments is an emerging problem all over the world. Comparing to other wastes, trace elements stabilization is more difficult both due to the wide range of contaminants present in the marine sediments and their inherent physicochemical properties. In this study, a pilot-scale experiment was performed to stabilize As, Cd, Cu, Mo, Ni, and Zn in a multi-contaminated sediment sample using hematite, zero-valent iron and zeolite. Results showed that iron-based amendments were able to reduce the leaching and the bioavailability of trace elements in the sediment sample, while zeolite was unsuitable. Chemical stabilization through iron-based amendments seems to be a promising approach as a low-cost alternative to traditional stabilization methods involving chemical reagents. [Copyright &y& Elsevier]

Co-firing residual char and pulverized coal can apply the residual char in pulverized coal combustion equipment, whose difficulties lie in poor ignition performance and low burnout efficiency. For the first time, residual char and bituminous coal fuel blend is experimentally co-fired under moderate or intense low-oxygen dilution (MILD) conditions. MILD co-combustion is achieved with low-temperature preheating air in a pilot-scale furnace. The co-firing experiments include swirl low-NO flame combustion, MILD combustion through symmetrical secondary air jets, and MILD combustion through an asymmetrical secondary air jet. The pilot-scale tests reveal that MILD co-combustion through the asymmetrical single nozzle achieves the lowest peak temperature and the most uniform distributions of temperature, heat flux, and gas compositions in the furnace. The NO emission of MILD co-combustion through the asymmetrical air jet is decreased by 57% compared with swirl low-NO flame co-combustion. The burnout rate of MILD co-combustion through the asymmetrical air jet reaches 94%. Considering more uniform in-furnace distribution, lower NO emission, and higher burnout rate, MILD combustion through the asymmetrical single nozzle shows more obvious advantages than that through symmetrical air nozzles. Overall, the present study further widens the fuel flexibility of MILD combustion even to residual char fuel blend. • Co-firing residual char under MILD combustion is realized for the first time. • MILD co-combustion of residual char can reduce fuel-NO emission by at least 54%. • Fuel flexibility of MILD combustion is even expanded to residual char fuel blend. [ABSTRACT FROM AUTHOR]

Optimizing the backwashing procedure of ultrafiltration membranes poses novel challenges in regards to the modeling and simulation of the fouling process. Traditional modeling approaches the problem through a physical and chemical understanding of the complicated fouling phenomena. In this study, a large amount of data has been collected from a pilot-scale ultrafiltration membrane system treating spent filter backwash water at a water treatment plant. Environmental variables and operational parameters including temperature, hydraulic pressure, water turbidity, etc. are monitored continuously. This work focuses on revealing the hidden nonlinear relationships of these variables via data driven methodologies without building a first principles process model. Machine learning tools are used to establish a connection between environmental variables, dynamic parameters, the efficiency of foulant removal through backwashing, and the increase rate of foulants. The prediction performance is compared to regression models including linear regression, artificial neural networks, and random forests. Our data driven model of the fouling dynamics is then used for optimization purposes, in particular, to optimize the backwashing sequence timing by applying tools from stochastic dynamic programming. Optimized backwash performance is compared with experimental data acquired via a fixed interval sequence and shows a more efficient schedule at less cost and with lower membrane resistance. This work establishes a full pipeline of data processing, model building, and operational optimization. The only requirement for employing our methodology is the collection of operational data, in order to identify the membrane dynamics. The reported methodology offers a great potential for implementation on large-scale ultrafiltration applications, which can improve energy consumption and elongate membrane life. Image 1 • Full pipeline of data analysis and dynamical parameter modeling have been developed. • Machine learning models and operational optimization are integrated. • A Markov decision model was used to describe UF membrane resistance evolution. • Backwash performance has been improved on both energy cost and membrane health. [ABSTRACT FROM AUTHOR]