Reduction In Content Research Articles

Evolution of high temperature oxidation properties of SiCf/SiCN composites with BN interphase

In this study, SiC/SiCN composites with BN interphase were prepared using chemical vapor infiltration (CVI) and polymer infiltration and pyrolysis (PIP) methods. The evolution and related mechanisms of mechanical and microwave absorption properties of the composites after oxidation at 800 °C, 1000 °C, 1200 °C, and 1400 °C were investigated. The results showed that with the elevating of oxidation temperature, the flexural strength of SiC/SiCN composites gradually decreased, with a retention rate of 56.7 % after oxidation at 1400 °C. The main reasons for the deterioration of mechanical properties were the changes in the crystal structure of SiC fibers under high-temperature conditions and the formation of brittle SiO2 phases on the surface and interior of the SiCN matrix. With the increase in oxidation temperature, the microwave absorption performance of the composites showed an enhancing trend. The main reasons were that after oxidation treatment, the reduction of free carbon content and the formation of SiO2 film layers from the oxidation of SiC and SiCN led to a decrease in the complex permittivity of the composites, resulting in better impedance matching and dielectric loss capabilities. The contributions of BN interphase to stress dispersion, interface polarization, and oxidation protection significantly enhance the mechanical and electromagnetic absorption properties of the composites. Therefore, SiC/SiCN composites are high-temperature structural microwave absorbing materials with great application prospects.

Insight into simultaneously sludge dewatering and antiviral drugs removal by integrated particle electrodes assisted electrochemical oxidation

Given the widespread occurrence of pandemic influenza, antiviral drugs (ATVs) as emerging pollutants which are ubiquitously present in wastewater and become concentrated in sewage sludge (SS). Therefore, achieving the simultaneous elimination of ATVs during sludge dewatering holds significant importance. Herein, six representative ATVs including amantadine, rimantadine, memantine hydrochloride, imiquimod, oseltamivir, and morpholidine were detected in sewage sludge. Their partitioning between solid and liquid phases was also examined under simultaneous sludge conditioning by particle electrodes-assisted electrochemical process (3D-SAC). The findings indicated that 3D-SAC significantly enhanced sludge dewaterability, achieving a moisture content reduction to 64.22 %. The total removal rates of the six ATVs ranged from 17.97 % to 66.22 %, closely associated with the degree of sludge cells cracking. Sludge lysis resulted in the destruction of protein-like EPS structures, exposing hydrophobic bonding sites, finally releasing more bonded water and ATVs into filtrate. The ·OH induced hydroxylation, backbone cleavage, and ring-opening of ATVs occurred concurrently as the sludge flocs disrupted and structural transformed. Environmental risk assessment revealed that the ecological risks and potential toxicity associated with the sludge filtrate were significantly diminished following electrochemical conditioning (EC). This process achieved the dual objectives of contaminant degradation and enhanced sludge dewatering.

Evaluating Seawater and Wood Distillate for Sustainable Hydroponic Cultivation: Implications for Crop Growth and Nutritional Quality

The adoption of innovative cultivation methods, such as hydroponics and aeroponics, is gaining attention due to the unprecedented demand for food that an increasing population is posing on agricultural systems, exacerbating the pressure on already limited arable land. Seeking sustainable and circular economy solutions is imperative, aiming to optimize water consumption and enhance crop yields and quality without resorting to synthetic chemical fertilizers. This study investigated the use of seawater at various concentrations as a base for nutrient solutions, with and without the addition of a natural biostimulant, wood distillate (WD). Four seawater (SW) concentrations (0, 3, 6, and 12%) and two wood distillate concentrations (0 and 0.2%) were applied to assess their impacts on lettuce growth. Findings reveal that seawater at low concentrations (< 6%) serves as an effective water-saving strategy, despite the reduction in the plant ascorbic acid contents. The addition of WD did not inflate growth; in fact, the results obtained are comparable to that of the controls for each concentration of seawater, except at the highest concentration (12% SW), resulting in reduced fresh leaf weights and root areas. Significantly, there was a notable increase in the ascorbic acid contents in all plants grown with WD. Moreover, the WD increased the leaf concentrations in Ca, Mg, P, and K, indicating the higher nutritional value of the crop. This research highlights the potential of combining seawater and WD for sustainable and efficient plant cultivation, suggesting new strategies for exploration across diverse plant species and hydroponic applications.

Ozone/biological aerated filter integrated process for recycled paper mill wastewater: A pilot-scale study

In this study, the effluent from recycled paper mill was treated using a combined ozone (O3) and biological aerated filter (BAF) process. Key operational parameters such as ozone dosage, pH, hydraulic retention time (HRT), volume load and gas-to-water ratio were optimized. Under optimal conditions, with a total ozone dosage of 100 g/m, a gas-to-water ratio of 4:1, and an HRT of 3.0 hours in the BAF, the chemical oxygen demand (COD) and chroma of the treated wastewater were reduced to 44–55 mg/L and 2–4 PCU, achieving removal efficiencies of 70 % and 95 %, respectively. The discharge effluent not only satisfy the new discharge standard of China (GB3544–2008), but also can be used as recycling water. Additionally, the treatment cost of wastewater was ca. 1.3 ¥/m3 in pilot-scale test, significantly decreasing the cost. Ozone pretreatment has a significant effect on wastewater decolorization by disrupting the molecular chemical structure of pollutants, which increase the biochemical properties of biofilm and is beneficial to the sequential BAF treatment. The sludge in the O3/BAF system exhibited increased biomass with minimal filamentous bacteria and higher dehydrogenase activity, confirming stable and robust bacterial growth. GC-MS analysis revealed substantial reduction in pollutant content and diversity post-treatment, although the recalcitrant compound (Z)-13-docosenamide remained relatively high, decreasing from 27.37 % to 21.14 %. The mechanism of the O3/BAF process for the pollutant degradation were also proposed. This study demonstrated that a combination of ozone and fixed biofilm treatment is an efficient and cost-effective treatment, providing the theory and practical applicability for the industrial wastewater.

A dual-chamber Microbial Electrolysis Cell for electromethanosynthesis from the effluent of cheese whey dark fermentation

Dark fermentation of cheese whey (CW) for the production of biohydrogen generates an acidic effluent, containing high concentrations of volatile fatty acids, which needs to be further treated before disposal and possibly further valorised. This study develops a dual-chamber Microbial Electrolysis Cell (MEC) that achieves simultaneously the reduction of the organic content of this effluent to environmentally acceptable levels, along with bio-electrochemical reduction of CO2 to CH4. The MEC was operated for 140 days and the effect of the following conditions on the MEC performance was examined: (a) the feed concentration of the acidic fermentate (in the range 6–81 gCOD/L), (b) the conductivity of the feed modified via KCl addition (range 2–22 mS/cm), (c) the MEC operation mode (with or without catholyte renewal) and (d) the solids content (modified via CW filtration prior to its use). The results showed that high COD removal (>95 %) was achieved in all cases, along with a CH4 production of up to 1.1 mmol/gCODconsumed. The best performance of the cell was obtained for a feed COD concentration of ∼30 gCOD/L and a feed conductivity of ∼15 mS/cm; these conditions resulted in a COD removal exceeding 99 %, a CH4 production of 1.1 mmolCH4/gCODconsumed and a net energy production of 15.8 % compared to the energy demand of the system. The electrochemical study of the system revealed that higher and lower feed COD concentrations were characterized by higher internal resistances. The results indicate that the MEC can be exploited for further treatment and valorization of a high-strength effluent along with the production of CH4 with an energy surplus, as an efficient waste-to-energy technology.

Exploring the effects of spontaneous and solid-state fermentation on the physicochemical, functional and structural properties of whole wheat flour (Triticum aestivum L.)

The effects of fermentation on various physicochemical and functional properties of whole wheat flour (Triticum aestivum L.) were investigated in this study. Firstly, changes in pH and total titratable acidity (TTA) were observed during spontaneous and solid-state fermentation. Spontaneous and solid-state fermentation led to a decrease in pH and a rapid increase in TTA, indicating effective acidification due to organic acid production. Both fermentation approaches significantly influenced the total starch and amylose content of wheat. The total starch content was decreased accompanied by a significant increase in apparent amylose content. This phenomenon was attributed to starch hydrolysis facilitated by microbial enzymes and organic acids, resulting in a higher amylose/amylopectin ratio. Chemical composition and mineral content of whole wheat flour were also affected. Fermentation led to reductions in moisture, crude fat, and crude protein content, while ash content increased. Furthermore, fermentation significantly impacted the soluble and total dietary fiber content of whole wheat flour, with an increase in soluble dietary fiber and a decrease in total dietary fiber. These changes were attributed to increased synthesis of non-cellulosic polysaccharides and β-glucans during fermentation. Moreover, fermentation resulted in reductions in gluten content, alterations in functional properties such as water and oil absorption capacity, changes in protein solubility, and modifications in gel texture properties. Finally, X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed minimal changes in the crystalline structure and morphology of starch granules during fermentation, with some signs of surface erosion and degradation, particularly in solid-state fermented samples. The results highlight the potential benefits of fermentation for improving the properties of whole wheat flour. This study contributes to a better understanding of the effects of fermentation on whole wheat flour, offering insights for the development of novel and improved whole wheat flour-based food products.

The Effect of One-Year Fermentation of Maesil Fruit (Prunus mume) Sugar Syrup on Amygdalin Level: A Natural Toxic Compound.

Prunus mume (maesil) is an economically important fruit in Korea. Recently, public interest in maesil sugar syrup is increasing. However, the presence of toxic amygdalin in the fruit syrup is a concern. Thus, the current investigation aimed to observe effects of maesil maturity, ripening methods, processing, and fermentation period on the amygdalin level in maesil sugar syrup. Six different types of maesil sugar syrup were prepared and amygdalin content was monitored at 3-month intervals. Higher levels (>63 mg/L) of amygdalin were found in syrups prepared from unripe fruit compared to those in syrups made from ripe fruit after 3 months of fermentation. A rapid reduction in amygdalin content was observed until 9 months in all syrups, gradually reducing to <5 mg/L at 12 months. More than 9 months of maturation is crucial for reducing the amygdalin content maesil sugar syrup, regardless of fruit maturity, source of fruit, and processing method.

Laboratory evaluation of wicking geotextile for moisture reduction in silty sands at different fines contents

The effect of fines content on the performance of the wicking geotextile is not clear. This study developed a simple moisture reduction test method to quantify the effectiveness of the wicking geotextile in reducing moisture in silty sands at four different fines contents and four different waiting periods. The sand was prepared at an initial moist condition based on its average field moisture capacity. A wicking or non-wicking woven geotextile was placed in the middle of a soil column. The effect of a geotextile on the moisture content of the sand was evaluated by measuring their gravimetric moisture contents at different distances from the geotextile at different times. Test results show that the amount of moisture reduced by the wicking geotextile decreased with the content of fines in the silty sand. On the contrary, the non-wicking geotextile obstructed water flow, hence moisture accumulated on it. The moisture content profile in the soil column indicated the influence zone by the wicking geotextile in the silty sand, which depended on the fines content. The percent of soil moisture content reduction by the wicking geotextile identified the limit of the fines content for the effectiveness of the wicking geotextile.

Grain boundary segregation of B and microstructure evolution in a hot-drawn Fe–B alloy

The grain boundary segregation (GBS) of boron and microstructure evolution in a hot-drawn Fe–B alloy are investigated utilising the Gleeble-1500, Auger electron spectrometer, time-of-flight secondary ion mass spectrometry, electron back-scattered diffraction, and transmission electron microscopy techniques. The results suggest substantial boron segregation at grain boundaries of the Fe–B alloy during the hot drawing process. In comparison to the contribution of dislocations to boron diffusion coefficients, the influence of vacancies is predominant. With the increase in hot-drawing temperature, the ratio of excess vacancy content to thermal equilibrium vacancy content [Formula: see text] decreases, and the content of low [Formula: see text] (low Sigma coincidence site lattice) boundaries increases, resulting in a reduction in boron GBS content. Additionally, elevating the hot-drawing temperature promotes dynamic recrystallisation and refines the grains. The volume fraction of the &lt;110&gt;//RD (rolling direction) texture component initially increases and then decreases with increasing temperature, reaching a maximum value of 64.6% at 830 °C, while the percentage of the &lt;100&gt;//RD + &lt;111&gt;//RD texture components exhibits the opposite trend, with a peak value of 27.4% observed at 1000 °C.

Bioinspired multilayer mulch film integrating mud repulsion, adhesion reduction, and antifouling for high-efficiency resource recycling

Resource recycling is a promising solution to the current problem of residual film pollution. However, the challenge that remains to be addressed in the resourcefulness of mulch films lies in mitigating heavy water and power consumption during the cleaning process. Herein, inspired by the unique structure of typical soil-dwelling insects, the mass production of high-strength multilayer mulch (Bio-HAM) films is achieved through a sequential combination of multilayer coextrusion, blow molding, roll-to-roll imprinting, and spray coating. The regular micro-nano hierarchical structure on the Bio-HAM films surface enables it to effectively inherit the antifouling, slurry repulsion, and adhesion reduction functions of the prototypes, even when exposed to ultraviolet radiation, deformation, and liquid or solid impact. Benefiting from the aforementioned properties, the Bio-HAM films exhibit low impurities adhering and soil wrapping during the entire planting cycle. The impurity content of the recovered Bio-HAM films wrapping is approximately 12.7 g/m2, which is a 67.4% reduction in impurity content compared to the basic films. Moreover, the recovered film also possesses favorable mechanical and thermal properties, thereby ensuring water and energy conservation as well as high-value regeneration. The proposed approach is expected to address the excessive consumption and persistent ecological pollution of residual film recycling.

Enhancing the Nutritional Quality of Defatted Cottonseed Meal by Solid-State Fermentation with Probiotic Microbes

Defatted cottonseed meal (DCSM), a byproduct of the cotton industry, is highly regarded for its high protein content, making it a source of nutrients in animal feed. Traditional physical and chemical treatments of DCSM can lead to a reduction in nutrient content and the presence of residual organic solvents. Probiotic fermentation of DCSM offers several advantages, including degradation of anti-nutritional factors, an increase in nutrient content, and production of beneficial metabolites. This study employed probiotic fermentation of DCSM using a probiotic microbe collection composed of Saccharomyces cerevisiae, Enterococcus faecium, and Lactiplantibacillus plantarum. This fermentation process significantly enhanced the nutritional quality of DCSM. Specifically, the contents of crude protein, free amino acid, total phosphorus, and moisture increased by 1.14-fold, 1.14-fold, 1.24-fold, and 3-fold, respectively. In the meanwhile, there was a substantial reduction in the content of dry matter, crude ash, and crude fat, with decreases of 27.83%, 25.74%, and 88.23%, respectively. Probiotic fermentation of DCSM resulted in an overall enhancement of the palatability of DCSM. This study provides valuable insights into the potential of mixed probiotic fermentation as a promising approach for improving the nutritional quality of DCSM.

Exploring microbial diversity and interactions for asbestos modifying properties

Asbestos poses a substantial environmental health risk, and biological treatment offers a promising approach to mitigate its impact by altering its chemical composition. However, the dynamics of microbial co-inoculation in asbestos bioremediation remain poorly understood. This study investigates the effect of microbial single cultures and co-cultures on modifying crocidolite and chrysotile fibers, focusing on the extraction of iron and magnesium. Seventy bacterial and eighty-three fungal strains were isolated from five diverse sites, characterized phylogenetically using the 16S rRNA gene and ITS region, respectively, and assessed for siderophore and organic acid production. Most bacterial strains were identified as Pseudomonas, while Penicillium predominated among fungal strains. Ten bacterial and 25 fungal strains were found to produce both organic compounds. Four microbial co-cultures (one bacterium-bacterium, two fungus-bacterium, and one fungus-fungus) exhibiting synergistic effects in plate assays, alongside their respective single cultures, were incubated with crocidolite and chrysotile. ICP-OES analysis revealed that in crocidolite, the co-culture HRF19–HRB12 removed more iron than their single cultures, while Penicillium TPF36 showed the highest iron removal. The co-culture of two Pseudomonas strains (HRB12–RB5) exhibited the highest magnesium concentration in the supernatant. In chrysotile, the co-culture HRB12–RB5 removed more iron than their individual cultures, with Penicillium TFSF27 exhibiting the highest iron concentration in the solution. Penicillium TFSF27 and the co-culture TFSF27–TPF36 demonstrated the highest magnesium removal. SEM-XRMA analysis showed a significant reduction in iron and magnesium content, confirming elemental extraction from the fibers' structure. This study significantly broadens the range of microbial strains capable of modifying asbestos fibers and underscores the potential of microbial co-cultures in asbestos remediation.

Sustainable tourism in the Tremiti Islands (South Italy)

An analysis of the pressure factors that influence the sustainable tourism in the Tremiti Islands (TI) has been performed. Tourist’s fluxes have been investigated in terms of monthly arrival and presences showing a high value of the territorial exploitation index with high number of arrivals, particularly in August, and low occupancy rate. Effects of climatic change has been analyzed in TI with reference to the increase of average air and sea temperature in the islands. Some measures of contrast to climate change and to favour sustainable tourism have been discussed also. The CO2 emissions by ferries transport, solid waste and wastewater treatment have been calculated. Environmental taxation for sustainable tourism aimed tat CO2 content reduction is also assessed identifying the value in 1.47 €/capita on the basis of the tourist arrivals and presences considering the environmental cost for CO2 removal and showing that tourism taxation should be well accepted if funds are destined to environmental purposes.

Low temperature exposure influences nitrogen metabolism resulting in decreased Cry1Ac insecticidal endotoxin content in cotton seeds

BackgroundSudden temperature drops, resulting from extreme weather events, often occur during the boll-setting period of cotton in Xinjiang, China, causing decreased expression of Bacillus thuringiensis (Bt) insecticidal proteins in cotton bolls. The precise threshold temperatures and durations that lead to significant changes in Cry1Ac endotoxin levels under low temperatures remain unclear. To address this, we investigated the effects of different temperatures and stress durations on Cry1Ac endotoxin levels in cotton bolls. In 2020–2021, two Bt transgenic cotton varieties, conventional Sikang1 and hybrid Sikang3, were selected as experimental materials. Various low temperatures (ranging from 16 to 20 °C) with different durations (12 h, 24 h and 48 h) were applied during the peak boll-setting period.ResultsAs the temperature decreased, the Cry1Ac endotoxin content in the boll shell, fiber, and seed exhibited a declining trend. Moreover, the threshold temperature which caused a significant reduction in Cry1Ac endotoxin content increased with the prolonged duration of low-temperature stress. Among the components of cotton bolls, seeds were most affected by low-temperature stress, with the threshold temperature for a significant reduction in Cry1Ac endotoxin content ranging from 17 °C to 19 °C. Correlation analysis indicated that low temperatures led to a decrease in protein synthesis capacity and an increase in degradation ability, resulting in reduced Cry1Ac endotoxin content. Pathway analysis revealed that both free amino acid and peptidase had significant negative effects on Cry1Ac endotoxin content.ConclusionIn summary, when the daily average temperature was ≤ 19 °C, implementing cultural practices to reduce free amino acid content and peptidase activity could serve as effective cold defense strategies for Bt cotton production.

Unlocking the antibacterial activity and mechanisms of ε-poly-l-Lysine and perilla combination against Pseudomonas fluorescens: Insights from non-targeted metabolomic analyses

Perilla frutescens extract has been acknowledged for its robust antibacterial properties, while ε-Poly-Lysine (ε-PL) stands as a naturally occurring food preservative. However, their combined antibacterial activity and mechanisms has not been fully understood. Therefore, the aim of this study was to elucidate the combined antibacterial activity of the ε-PL/Perilla combination against Pseudomonas fluorescens. The findings unveiled a significant antibacterial efficacy of ε-PL and perilla against P. fluorescens, respectively. Upon treatment with ε-PL and perilla, a decline in membrane potential (MP) was observed. These alterations were further accompanied by reductions in nucleic acid content, metabolic activity, and respiratory chain dehydrogenase activity. And by morphological observation, it was found that the cells treated with perilla or ε-PL were severely broken. The metabolomic analysis following treatment with ε-PL and perilla unveiled substantial shifts in a multitude of metabolites. Multivariate statistical analysis showed that ε-PL and perilla hindered nucleotide metabolism and interfered with carbohydrate, amino acid, and lipid metabolism, impacting cell wall biosynthesis, cell membrane structure, and genetic material expression, leading to growth inhibition and bacterial demise. Collectively, these outcomes provide fresh insights into the intricate mechanisms underlying the inhibitory action of ε-PL and perilla against P. fluorescens.

In Situ High‐Temperature X‐ray Diffraction Study of the Thermal Stability of the Co0.22Cr0.23Fe0.29Ni0.20Ti0.06 High‐Entropy Alloy Produced by High‐Energy Ball Milling

In this report, the effect of Ti addition on the phase evolution of a near‐equiatomic CoCrFeNi‐based high‐entropy alloy (HEA) during annealing in a vacuum is described. The HEA Co0.22Cr0.23Fe0.29Ni0.20Ti0.06 is synthesized through mechanical alloying of constituent elements for a milling duration of 1 h. The as‐prepared HEA is a two‐phase alloy containing body centred cubic (BCC) precipitates in an face centred cubic (FCC) matrix. The thermal stability of the HEA is experimentally studied by subjecting it to 5 h of isothermal annealing at 600, 800, and 1000 °C, using high‐temperature X‐ray diffraction (HTXRD). The HTXRD analysis indicates a noteworthy reduction in the BCC phase content after isothermal annealing at 600 °C. The formation of intermetallic σ‐phases does not occur. At temperatures of 800 and 1000 °C, the alloy matrix exhibits a single‐phase FCC solid solution. At 800 and 1000 °C, HEA undergoes partial oxidation, resulting in the formation of oxide phases on the surface and within the particles of the powder in the form of nanoscale inclusions. This oxidation depletes the metal matrix with titanium, leading to a change in the composition of the HEA. The alloy transforms into a CoCrFeNi solid solution containing 3–4 at% Ti. Thus, the alloy matrix phase remains a stable FCC solid solution.

Effect of pumping process on the properties of 3D printed concrete containing air-entraining agent

Using 3D printing technology in the construction industry is growing rapidly due to its numerous advantages. However, understanding various influencing factors on this technique is crucial. Among these, the concrete pumping process can significantly impact printed concrete’s properties. The results indicate that the pumping process can alter the structure of void spaces, reduce the air content, and increase the compressive strength of concrete. Mainly, the mechanisms of mechanical entrapment, reduction of air content and increase of hydration kinetics respectively cause these changes in air content and compressive strength due to pumping. In the control samples, the fresh air content decreased by 47% and the compressive strength increased by 4.3%. The creation of stable air bubbles using air-entraining agents can lead to a decrease in change of air content and compressive strength. By using 0.12% air-entraining agent, the drop in air content due to pumping reached about 23–25%. It also appears that, depending on the amount of entrained air in the mixture, pumping can affect its flowability differently. Highlights The pumping process is an essential component in 3D printed concrete, so it is necessary to see the effect of this process on the properties of printed concrete, especially its fresh properties. Although the addition of an air-entraining agent can help concrete resist freezing and thawing cycles, what matters is the air content in the hardened state. Concrete pumping can change the structure of concrete voids and affect its various properties.

The impact of the English calorie labelling policy on the energy content of food offered and purchased in worksite cafeterias: a natural experiment

BackgroundOn 6 April 2022, legislation came into effect in England requiring calorie labels to be applied to food items on menus of larger food businesses. This study aimed to assess the impact of calorie labelling on (a) food purchased and (b) energy content of menu options in worksite cafeterias.MethodsProduct-level sales data and energy content of available items was obtained from 142 worksite cafeterias from January 2022-October 2022. Interrupted-time-series (ITS) analysis with level and slope change evaluated daily energy (kcal) purchased per item, and ITS with level change assessed mean energy per option available on menus before and after calorie labelling. Each analysis was conducted 6 weeks and 6 months from implementation. A post-hoc ITS examined weekly energy purchased per item over a longer period (March 2021-October 2022; 135 sites).ResultsThere was no evidence calorie labelling changed the energy content of foods purchased (6-week: + 0.60 cal/product, 95%CI:-2.54, + 3.75; 6-month: + 1.59 cal/product, 95%CI:-0.96, + 4.16). Post-hoc analyses suggested calorie labels were associated with a reduction in mean energy of items purchased over time (-0.65 kcal/week, 95%CI:-0.81,-0.49), but a significant increase (+ 3 kcal, 95%CI: + 0.43, + 5.60) at the point of implementation. There was a reduction in the mean energy content of menu options at each seasonal menu change (April 2022:-1.79 kcal, 95%CI:-3.42,-0.15; July 2022:-4.18 kcal, 95% CI:-7.65,-0.73).ConclusionThis large observational study in worksite cafeterias found no evidence to indicate the introduction of calorie labelling led to any immediate reduction in energy purchased by customers. There was some evidence of increasing impact over time, possibly associated with changes in menu offerings, but this effect was small and cannot be directly attributed to calorie labelling.

Effects of ash formation during co-firing refuse-derived fuel with coal on initial superheater material degradation

ABSTRACT Refuse-derived fuel (RDF) has significant potential as a co-firing fuel in power plants. However, its different characteristics from coal, particularly the high chlorine (Cl) concentration in the ash deposits, can degrade metal elements during combustion. This study aims to investigate the effect of adding RDF to coal on the initial degradation of materials caused by ash deposits during combustion. This research is conducted on a laboratory scale using a drop tube furnace to simulate pulverized coal boiler conditions, analyzying ash deposits, mineral transformations, and evaluating the microstructure of the probe material. The results show that the chlorine content in the R-10 at 0.035 wt% substantially affects the initial degradation of 18Cr-Ni during combustion. The oxide layer begins to degrade in the second hour due to ash deposits, reaching 2.38 μm. The presence of Ca (1.11%), K (1.66%), Na (4.46%), and Cl (0.42%) increases to 1.12% on the metal surface, gradually attacking the substrate area and forming cavities. Degradation increases linearly up to probe-8, resulting in a thickness loss of 3.81 μm and a significant reduction in chromium content, which decreases by 12.54%. These findings highlight the importance of understanding the impact of chlorine levels in RDF, which can aggressively attack and corrode metals.

Heterotrophic activity and hydrocarbon degradation in crude oil-contaminated coastal soil augmented with indigenous biosurfactant producing Pseudomonas sp.

The enhanced bioremediation of the petroleum-contaminated soil from the Ibeno coastal area was investigated using standard microbiological and biotechnological methods. Soil samples were simulated with 200ml, 400ml, and 800ml of Bonny Light crude oil representing 5%, 10%, and 20 % contamination levels respectively, and allowed to mimic natural crude oil degradation for 48 hours. The contaminated soil was bioaugmented with 15 ml of 24-hour culture of potent biosurfactant-producing bacteria – Pseudomonas aeruginosa with a viable cell count of 2.6 x 103 CFU/ml and monitored for 12 weeks. Analysis of the fate of the hydrocarbon contamination in soil augmented with the biosurfactant-producing pseudomonad revealed that the degradation of total petroleum hydrocarbon (TPH) and polycyclic aromatic hydrocarbons (PAHs) was faster in augmented soils. At the end of the degradation, the augmentation process induced a reduction in the TPH content and PAH levels of soil exposed to 20% contamination from 32.85 mg/kg to 15.14 mg/kg and from 16.34 mg/kg to 5.35 mg/kg respectively. These represent 45.9% and 32.7% remediation rates of TPH and PAH, respectively. The findings of this study also indicate that bioaugmentation of crude oil-contaminated soil with a culture of P. aeruginosa, does not only influence the density of heterotrophic and hydrocarbon-degrading bacteria in the soil but increases the natural attenuation potentials of the contaminated soil.