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The COVID-19 pandemic of 2020, marked by stringent lockdowns and reduced human activity, resulted in a significant decrease in air pollutant emissions. This study investigates the impact of these altered atmospheric conditions on human health by focusing on Volatile Organic Compounds (VOCs) such as benzene, toluene, and meta-xylene (BTX), comparing data from before, during, and after the pandemic lockdowns. The objectives were to assess changes in Total VOC (TVOC) concentrations and to evaluate the associated health risks, particularly Lifetime Cancer Risk (LCR) from benzene exposure. Analysis of the data revealed a notable reduction in TVOCs during the 2020 lockdown, with average concentrations of 12.15 ± 20.49 µg/m3 in 2019, 8.08 ± 5.50 µg/m3 in 2020, and 5.12 ± 7.56 µg/m3 in 2021. LCR values also fluctuated, with averages of 1.12 × 10−5, 1.23 × 10−5, and 6.91 × 10−6 or pre-pandemic, during-pandemic, and post-pandemic periods, respectively. The findings highlight the potential effectiveness of lockdowns in reducing air pollution and underscore the need for continued, targeted environmental policies to improve public health. [ABSTRACT FROM AUTHOR]

Various toxic and flammable gases exist in the fertilizer industry whose release quantification is very important regarding emergency preparedness, planning and response, and well-being of the community. ALOHA threat zones and threat at a point coupled with MARPLOT are evaluated for ammonia, methane, carbon dioxide and hydrogen release, and outdoor and indoor concentrations of these gases in nearby residences and highways calculated. These footprints are calculated using ALOHA which requires inputs such as site data, site location, building type, gas name, atmospheric inputs, release source information and dispersion model to display the threat zone, which can then be shown on MARPLOT. Potential impact of these releases on the community is mitigated through releasing equipment isolations, water sprays for dilutions, dilutions through steam or air and emergency sirens for information. This article covers hazards in the fertilizer industry, and provides general guidelines for operational staff of any industry to mitigate hazards. [ABSTRACT FROM AUTHOR]

Most tilapias are microphytes, but some prefer higher plants. Ammonia is one of the most important toxic compounds of nitrogen, which is a serious problem in the environment and aquaculture industry. In the present study, juvenile Oreochromis niloticus were exposed to 10, 20, and 30% (96h LC50) of ammonia for two weeks, which are equivalent to 0.9, 1.8, and 2.7 mg / l, respectively. After this period, the fish were anesthetized and blood samples were taken from the caudal stalk with a heparin syringe for evaluating blood indicators. The tissue samples were taken 0.5 cm from the liver, fixed in 10% formalin buffer, and after dehydration with alcohol, clarification with xylol, blocking with paraffin, and cutting 4-6 microns thick with microtome were done. Finally, the stained slides were studied with a light microscope. The results showed phenomena such as hyperemia, nuclear hypertrophy, sinusoidal dilatation, increased melanomacrophage centers, nucleus margination, hepatocyte vacuolation, and cell necrosis in the liver. In the studies of blood serum factors with the increase of ammonia, it has been increased in AST, ALT, and ALP compared to the control and other groups. Also, as the ammonia concentration increased, the severity of the lesions also increased. Therefore, ammonia causes changes in the structure and activity of metabolic enzymes of the liver, which must be controlled by creating the appropriate ammonia and management conditions in the aquatic environment. [ABSTRACT FROM AUTHOR]

Introduction: Determining the etiology of an encephalopathy can be challenging for the neurologists, especially when the preliminary investigations do not indicate any significant biochemical or other systemic abnormality. Portosystemic shunts maybe easily missed and may present as recurrent encephalopathy with elevated serum ammonia or cerebrospinal glutamate levels. These shunts maybe easily identified in the presence of overt chronic liver disease, but maybe easily missed in patients with cryptogenic liver disease or in congenital abnormalities of the intrahepatic vascular system without an associated chronic liver disease. Materials and Methods: The triple-phase computed tomography (CT) or contrast magnetic resonance imaging can demonstrate the extent of portal vein thrombosis, map the extent of the portosystemic collateral, and aid in planning the treatment in patients with difficult anatomy of the portosystemic collaterals. Treatment regimens for patients with portosystemic shunts manifesting as hyperammonemic encephalopathy include restriction of oral protein intake, lactulose administration, oral nonabsorbable antibiotics, closure of the endovascular shunt, or finally, liver transplant. We present a case of a 55-year-old female with seizure disorder presenting with recurrent episodes of encephalopathy with elevated serum ammonia without the overt signs of chronic liver disease with identification of portosystemic shunting on a triple-phase CT of the abdomen. Conclusion: Specialized investigations to identify the presence of portosystemic collaterals should be conducted in patients with cryptogenic encephalopathy with elevated serum ammonia. [ABSTRACT FROM AUTHOR]

Extended exposure to airborne contaminants such as ammonia (NH3) and respirable dust in swine facilities has been associated with various health problems among swine barn workers. The overall goal of this study was to assess the impact of selected control measures, namely, canola oil sprinkling, low crude protein diet, high level of cleaning, and manure pH manipulation, on NH3 and respirable dust concentrations in swine production rooms through area sampling and on worker exposure to these contaminants in accordance with National Institute of Occupational Safety and Health (NIOSH) methods for occupational exposure monitoring. Results from five trials showed that low crude protein diet can be used for reducing worker exposure to NH3 while oil sprinkling can be used for controlling respirable dust levels in swine rooms. Reduction in airborne levels did not translate to reduction in occupational exposure. Commercial NH3 monitors showed higher readings than the standard NIOSH 6015 method. [ABSTRACT FROM AUTHOR]

A fill-and-draw flushing test on a landfill cell containing MSW waste was carried out to examine the operational viability of this method for accelerating the flushing of contaminants and landfill stabilisation. During the fill cycle, 800 m 3 of water containing the tracer bromide was pumped into the base of a 0.44 ha landfill cell, resulting in the estimated saturation of 9,400 m 3 of waste. Abstraction took place in two phases, during which 1,100 m 3 of tracer/leachate was recovered. Samples of leachate were analysed for the tracer, electrical conductivity and indigenous solutes chloride and ammonia. Tracer recovery was between 63 and 72 % for bromide. An estimated 227 kg of ammonia and 575 kg of chloride were removed. Test data was used to calibrate a 1D, dual-porosity model involving advection in a mobile zone, and diffusion into 'blocks' of a less mobile zone. The model fitted well to the early time data, whereas later data appears to have been affected by recharge. The results of this trial demonstrate the possibilities of the 'fill-and-draw' concept using the basal leachate drainage system of landfills as a potential accelerated landfill remediation technique. However, modelling results suggest low contaminant removal efficiency. Including a pause between the fill and the draw cycles improves mass removal., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Tristan Rees-White reports financial support was provided by Engineering and Physical Sciences Research Council. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.]., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

We report a novel system consisting of a redox reaction and a highly efficient reductase-like nanozyme, silica-palladium nanoparticles (Pd@SiO 2 NPs), as a novel detection platform for fluorometric sensing. In a proof-of-concept demonstration using an oligonucleotide as the detection target, a glass fiber-based sensor is fabricated by covalently conjugating two oligo probes, which are complementary to the adjacent segments of the target oligonucleotide, on Pd@SiO 2 NPs and glass fiber, respectively. In the presence of the target oligonucleotide, the two probes are drawn together by the target through sequence-specific hybridization, bringing the Pd@SiO 2 NPs to the glass fiber. When the glass fiber is subsequently immersed in a mixture of resazurin and ammonia borane solution, the Pd@SiO 2 NPs on the glass fiber trigger the catalytic conversion of resazurin (blue, slightly fluorescent) to resorufin (pink, highly fluorescent) with massive signal amplification, indirectly signaling the presence of the target oligonucleotide. We show that the glass fiber-based fluorometric sensor can detect a target oligonucleotide associated with the BRAF mutation linearly in the concentration range of 20 to 400 pM with a detection limit (LOD) of 15 pM and the specificity to differentiate targets with single-base difference. These results demonstrate a new frontier for the development of a sensitive, specific, and inexpensive nonenzyme-based fluorometric sensing platform as an alternative to conventional enzyme-based assays.

Mitigating the environmental impact of composting by the reduction of greenhouse gases (N 2 O, CH 4 ) and ammonia (NH 3 ) emissions is a major challenge. To meet this challenge, the understanding of the relationships between composted substrates initial physicochemical parameters and gas emissions is essential. From a long-term perspective, it will allow to guide the recipe formulation of the initial mixture to be composted, with a view to reducing gas emissions during composting. This study gathered literature data targeting sewage sludge composting and performed statistical correlation analyses between cumulative gas emissions and the following parameters: sewage sludge, bulking agent and composted mixture initial physicochemical parameters (pH, dry matter, total carbon, total nitrogen, C/N), the dry mass ratio of sewage sludge to bulking agent and the duration of composting. The average values of cumulative emissions show a large variability: 1.37 ± 2.71 gC.kg initial mix DM -1 , 0.13 ± 0.17 gN.kg initial mix DM -1 and 2.23 ± 2.79 gN.kg initial mix DM -1 for CH 4 , N 2 O and NH 3 emissions respectively. Although the correlation analysis highlighted some significant interesting correlations between initial physicochemical parameters and gas emissions (p.value < 0.05), reliable multiparametric model could not fit the data, meaning that the actual literature data are not sufficient to explain most part of gas emissions. Among the most interesting relationships, the study showed that the dry matter of the composted mixture is negatively correlated to N 2 O emissions, while the ratio of sewage sludge to bulking agent and the duration of composting are positively correlated to N 2 O emissions. It was also shown that the pH of the bulking agent is positively correlated to NH 3 emissions. Considering the large part of the emission variability that is not explained and the difficulty to link the correlation with their causality, it will be interesting to improve composting gas emissions knowledge in future research by analyzing free air space, bulking agent adsorption capacity and available and biodegradable organic matter. These parameters are of particular interest in solving the main problems associated with sewage sludge composting, namely porosity and nitrogen retention. This study also highlighted the necessity to extend the duration of the composting studies over 40 days in order to measure possible N 2 O late release and better identify parameters influencing N 2 O emissions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A combined process of coagulation pretreatment and three-stage membrane aeration biofilm reactor (MABR) system was successfully applied for the first time to treat actual municipal solid waste leachate (MSWL), which was characterized by high concentrations of toxic hard-to-degrade organics and salinity. The results showed that 9.8%-21.3% of organics could be removed from actual MSWL by coagulation with polymeric aluminum chloride (PAC). Three-stage MABR contributed 95.6% of the chemical oxygen demand (COD) removal, with the influent COD concentration ranging from 6000 to 7000 mg/L. At the same time, the removal efficiencies of total nitrogen (TN) and ammonia (NH 4 + -N) could reach to 84.3% and 79.9% without the addition of external carbon source, respectively. The nitrifying/denitrifying bacteria were enriched in the biofilm including Thiobacillus, Azoarcus and Methyloversatilis, which supported the MABR with high nitrogen removal efficiency and significantly toxic tolerance. Principal component analysis (PCA) and the Pearson correlation coefficients (r) illustrated that aeration pressure is a crucial operational parameter, exhibiting a strong correlation between the MABR performance and microbial communities. This work demonstrates that MABR is an effective and low-energy option for simultaneous removal of carbon and nitrogen in the treatment of MSWL., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Intelligent food packaging has recently gained significant attention due to the heightened consumer awareness regarding food quality. Although anthocyanins avoid safety issues, the instability and leakage of anthocyanins restrict their utilization in freshness indicator labels. In this study, we introduced an innovative metal-organic framework (UiO-66-NH 2 ) synergistic pH-colorimetric label with fast ammonia-responsive, incorporating sodium alginate, red cabbage anthocyanin, and UiO-66-NH 2 . The cross-linked sodium alginate substrate enabled the label to possess superior insolubility. The microscopic morphology of the labels was intricately analyzed, while their sensitivity was rigorously tested utilizing ammonia as a representative gas. Due to the remarkable UV absorption capability of UiO-66-NH 2 and various molecular interactions with anthocyanins, the label exhibited good UV absorption, enhanced stability, and optimized performance in reducing anthocyanin leakage, ensuring the stability and effectiveness of the labels in practical applications. The prepared label exhibited good specificity for volatile amines and ammonia gases, and robust anti-interference properties, enabling visualization and early detection of shrimp spoilage during storage at different temperatures. The strategy employed in this study presents promising new possibilities for developing intelligent packaging solutions for food products., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The composting performance and nitrogen transformation during membrane-covered aerobic composting of kitchen waste were investigated. The aerobic composting products of the kitchen waste had a high seed germination index of ∼180%. The application of the membrane increased the mean temperature in the early cooling stage of composting by 4.5℃, resulted in a lower moisture content, and reduced the emissions of NH 3 and N 2 O by 48.5% and 44.1%, respectively, thereby retaining 7.9% more nitrogen in the compost. The adsorption of the condensed water layer under inner-membrane was the reason for reducing NH 3 emissions, and finite element modeling revealed that the condensed water layer was present throughout the composting process with a maximum thickness of ∼2 mm in the thermophilic stage. The reduction of N 2 O emissions was related to the micro-positive pressure in the reactor, which promoted the distribution of oxygen, thus weakening denitrification. In addition, the membrane cover decreased the diversity of the bacterial community and increased the diversity of ammonia-oxidizing strains. This study confirmed that membrane-covered composting was suitable for kitchen waste management and could be used as a strategy to mitigate NH 3 and N 2 O emissions.

Monitoring chemical levels is crucial for safeguarding both the environment and public health. Elevated levels of ammonia, for instance, can harm both humans and aquatic ecosystems, often indicating contamination from agriculture, industry, or sewage. Developing portable, high-resolution, and affordable methods for in situ monitoring of ammonia is thus imperative. Plasmonic sensors offer a promising solution, detecting ammonia by correlating changes in their optical response to the target analyte's concentration. While they are highly sensitive and can be fabricated in a variety of portable and user-friendly formats, some still require reagents or expensive optical equipment, which hinder their widespread adoption. Here, we present a self-assembled nanoplasmonic colorimetric sensor capable of directly detecting ammonia concentrations in aqueous matrices. The proposed sensor exploits the plasmonic resonance of the nanostructures to transduce changes in the chemical environment into alterations in color, offering a label-free method for real-time analysis. The sensor is fabricated using a self-assembling technique compatible with low-cost mass production based on aluminum and aluminum oxide, ensuring affordability and avoiding the use of other toxic chemicals. We developed a model to predict ammonia concentrations based on visible color change of the sensor, achieving a detection limit of 8.5 ppm. Furthermore, to address the need for on-site detection, we integrated smartphone technology for real-time color change analysis, eliminating the need for expensive, bulky optical instruments. Indeed, our approach offers a cost-effective, portable, and user-friendly solution for ammonia detection in water without the need for chemical reagents or spectrometers, making it ideal for field applications. Interestingly, this platform extends its applicability beyond ammonia detection, enabling the monitoring of various chemicals using a smartphone, without the need for any additional costly equipment.

Detecting and distinguishing between hazardous gases with similar odors by using conventional sensor technology for safeguarding human health and ensuring food safety are significant challenges. Bulky, costly, and power-hungry devices, such as that used for gas chromatography-mass spectrometry (GC-MS), are widely employed for gas sensing. Using a single chemiresistive semiconductor or electric nose (e-nose) gas sensor to achieve this objective is difficult, mainly because of its selectivity issue. Thus, there is a need to develop new materials with tunable and versatile sensing characteristics. Phase engineering of two-dimensional materials to better utilize their physiochemical properties has attracted considerable attention. Here, we show that MoSe 2 phase-transition/CeO 2 composites can be effectively used to distinguish ammonia (NH 3 ) and triethylamine (TEA) at room temperature. The phase transition of nanocomposite samples from semimetallic (1T) to semiconducting (2H) prepared at different synthesis temperatures is confirmed via X-ray photoelectron spectroscopy (XPS). A composite sensor in which the 2H phase of MoSe 2 is predominant lacks discrimination capability and is less responsive to NH 3 and TEA. An MoSe 2 /CeO 2 composite sensor with a higher 1T phase content exhibits high selectivity for NH 3 , whereas one with a higher 2H phase content (2H > 1T) shows more selective behavior toward TEA. For example, for 50% relative humidity, the MoSe 2 /CeO 2 sensor's signal changes from the baseline by 45% and 58% for 1 ppm of NH 3 and TEA, respectively, indicating a low limit of detection (LOD) of 70 and 160 ppb, respectively. The composites' superior sensing characteristics are mainly attributed to their large specific surface area, their numerous active sites, presence of defects, and the n-n type heterojunction between MoSe 2 and CeO 2 . The sensing mechanism is elucidated using Raman spectroscopy, XPS, and GC-MS results. Their phase-transition characteristics render MoSe 2 /CeO 2 sensors promising for use in distributed, low-cost, and room-temperature sensor networks, and they offer new opportunities for the development of integrated advanced smart sensing technologies for environmental and healthcare.

Ammonia (NH 3 ) in exhaled breath (EB) has been a biomarker for kidney function, and accurate measurement of NH 3 is essential for early screening of kidney disease. In this work, we report an optical sensor that combines ultraviolet differential optical absorption spectroscopy (UV-DOAS) and spectral reconstruction fitting neural network (SRFNN) for detecting NH 3 in EB. UV-DOAS is introduced to eliminate interference from slow change absorption in the EB spectrum while spectral reconstruction fitting is proposed for the first time to map the original spectra onto the sine function spectra by the principle of least absolute deviations. The sine function spectra are then fitted by the least-squares method to eliminate noise signals and the interference of exhaled nitric oxide. Finally, the neural network is built to enable the detection of NH 3 in EB at parts per billion (ppb) level. The laboratory results show that the detection range is 9.50-12425.82 ppb, the mean absolute percentage error (MAPE) is 0.83%, and the detection accuracy is 0.42%. Experimental results prove that the sensor can detect breath NH 3 and identify EB in simulated patients and healthy people. Our sensor will serve as a new and effective system for detecting breath NH 3 with high accuracy and stability in the medical field.

Nitrogen dioxide (NO 2 ) is a significant environmental and human health hazard. Current NO 2 sensors often lack sensitivity and selectivity under ambient conditions. This study investigates ammonia pyrolysis modification of monolayer Ti 3 C 2 T x MXene to enhance NO 2 detection at room temperature. Nitrogen-doped Ti 3 C 2 T x demonstrates a substantial improvement in sensitivity, with a response of 8.87% to 50 ppm of NO 2 compared to 0.65% for the original sensor, representing a 13.8-fold increase. The nitrogen-doped sensor also exhibits superior selectivity and linearity for NO 2 under ambient conditions. Theoretical analysis shows that nitrogen incorporation promotes enhanced interaction between Ti 3 C 2 T x and its surface oxygen-containing functional groups through electronic hybridization, resulting in improved adsorption energy (1.80 |eV|) and electron transfer efficiency (0.67 |e|) for NO 2 , thereby enhancing its gas-sensing performance. This study highlights the potential of ammonia pyrolysis-treated Ti 3 C 2 T x MXene for advancing NO 2 sensor technologies with heightened performance at room temperature.

Ambient pressure X-ray photoelectron spectroscopy (APXPS) is combined with simultaneous electrical measurements and supported by density functional theory calculations to investigate the sensing mechanism of tungsten disulfide (WS 2 )-based gas sensors in an operando dynamic experiment. This approach allows for the direct correlation between changes in the surface potential and the resistivity of the WS 2 sensing active layer under realistic operating conditions. Focusing on the toxic gases NO 2 and NH 3 , we concurrently demonstrate the distinct chemical interactions between oxidizing or reducing agents and the WS 2 active layer and their effect on the sensor response. The experimental setup mimics standard electrical measurements on chemiresistors, exposing the sample to dry air and introducing the target gas analyte at different concentrations. This methodology applied to NH 3 concentrations of 100, 230, and 760 and 14 ppm of NO 2 establishes a benchmark for future APXPS studies on sensing devices, providing fast acquisition times and a 1:1 correlation between electrical response and spectroscopy data in operando conditions. Our findings contribute to a deeper understanding of the sensing mechanism in 2D transition metal dichalcogenides, paving the way for optimizing chemiresistor sensors for various industrial applications and wireless platforms with low energy consumption.

Wearable sweat sensors are reshaping healthcare monitoring, providing real-time data on hydration and electrolyte levels with user-friendly, noninvasive devices. This paper introduces a highly portable two-channel microfluidic device for simultaneous sweat sampling and the real-time detection of volatile organic compound (VOC) biomarkers. This innovative wearable microfluidic system is tailored for monitoring diabetes through the continuous and noninvasive tracking of acetone and ammonia VOCs, and it seamlessly integrates with smartphones for easy data management. The core of this system lies in the utilization of carbon polymer dots (CPDs) and carbon dots (CDs) derived from monomers such as catechol, resorcinol, o -phenylenediamine, urea, and citric acid. These dots are seamlessly integrated into hydrogels made from gelatin and poly(vinyl alcohol), resulting in an advanced solid-state fluorometric sensor coating on a cellulose paper substrate. These sensors exhibit exceptional performance, offering linear detection ranges of 0.05-0.15 ppm for acetone and 0.25-0.37 ppm for ammonia, with notably low detection limits of 0.01 and 0.08 ppm, respectively. Rigorous optimization of operational parameters, encompassing the temperature, sample volume, and assay time, has been undertaken to maximize device performance. Furthermore, these sensors demonstrate impressive selectivity, effectively discerning between biologically similar substances and other potential compounds commonly present in sweat. As this field matures, the prospect of cost-effective, continuous, personalized health monitoring through wearable VOC sensors holds significant potential for overcoming barriers to comprehensive medical care in underserved regions. This highlights the transformative capacity of wearable VOC sweat sensing in ensuring equitable access to advanced healthcare diagnostics, particularly in remote or geographically isolated areas.

Inevitably, aerobic biological treatment processes generate emissions of ammonia (NH 3 ) and greenhouse gas (GHGs) emissions, especially nitrous oxide (N 2 O). The rapid bio-drying process (RBD) for food waste (FW) alleviates issues arising from its substantial growth. However, its emissions of NH 3 and N 2 O remain unknown, and the correlation with nitrogen components in the substrate remains unclear, significantly impeding its widespread adoption. Here, the nitrogen loss and its mechanisms in RBD were investigated, and the results are as follows: The total emission of NH 3 and N 2 O were1.42 and 1.16 mg/kg FW (fresh weight), respectively, achieving a 98 % reduction compared to prior studies. Structural equation modeling demonstrates that acid ammonium nitrogen (AN) decomposition chiefly generates NH 3 in compost (p < 0.001). Strong correlation (p < 0.001) exists between amino acid nitrogen (AAN) and AN. In-depth analysis of microbial succession during the process reveals that the enrichment of Brevibacterium, Corynebacterium, Dietzia, Fastidiosipila, Lactobacillus, Mycobacterium, Peptoniphilus, and Truepera, are conducive to reducing the accumulation of AN and AAN in the substrate, minimizing NH 3 emissions (p < 0.05). While Pseudomonas, Denitrobacterium, Nitrospira, and Bacillus are identified as key species contributing to N 2 O emissions during the process. Correlation analysis between physicochemical conditions and microbial succession in the system indicates that the moisture content and NO 3 - levels during the composting process provide suitable conditions for the growth of bacteria that contribute to NH 3 and N 2 O emissions reduction, these enrichment in RBD process minimizing NH 3 and N 2 O emissions. This study can offer crucial theoretical and data support for the resource utilization process of perishable organic solid waste, mitigating NH 3 and GHGs emissions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study investigated the performance of the full-scale unit over a two-year period to enhance nitrification efficiency and provide operational strategies. Results indicated that raw water quality from Donggan River was notably influenced by seasonal variations, particularly during dry and wet seasons, impacting the nitrification efficiency of the biological pretreatment process. Factors such as influent concentrations of ammonia and total Kjeldahl nitrogen were found to have significant effects on nitrification, with temperature and conductivity also showing correlations. The specific rate of ammonia removal was calculated to be approximately 0.1 kg-N/m 3 /d under the existing operational setup. Moreover, elevating dissolved oxygen levels above 4 mg/L was proposed to potentially boost ammonia oxidation based on findings from experiments conducted in lab-scale bioreactors. In times of increased influent ammonia levels, the elimination of about 1-3 mg-N/L of total nitrogen signified the activation of denitrification processes. This observation was corroborated by results from next-generation sequencing techniques, verifying the existence of denitrifying microorganisms. The real-time PCR analysis results indicated that the abundance of comammox amoA gene was comparable with the abundance of the AOB amoA gene, indicating the presence of comammox Nitrospira and their potential role on nitrification in the system., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Ammonia (NH 3 ) plays an important role in the formation of atmospheric particulate matter, but the contribution of traffic-related emissions remains unclear, particularly in megacities with a large number of vehicles. Taking the opportunity of the stringent COVID-19 lockdowns implemented in Beijing and Shanghai in 2022, this study aims to estimate the traffic-related NH 3 emissions in these two megacities based on satellite observations. Differences between urban and suburban areas during the lockdown and non-lockdown periods are compared. It was found that despite different dominating sources, the overall NH 3 concentrations in urban and suburban areas were at a similar level, and the lockdown resulted in a more prominent decrease in urban areas, where traffic activities were most heavily affected. The traffic-related contribution to the total emission was estimated to be ∼30% in megacities, and ∼40% in urban areas, which are about 2-10 times higher than that in previous studies. The findings indicate that the traffic-related NH 3 emissions have been significantly underestimated in previous studies and may play a more critical role in the formation of air pollution in megacities, especially in winter, when agricultural emissions are relatively low. This study highlights the importance of traffic-related NH 3 emissions in Chinese megacities and the need to reassess the emissions and their impacts on air quality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

For the first time, a hyper-thermophilic aerobic (>60 °C) bioreactor has been integrated with direct submerged membrane distillation (MD), highlighting its potential as an advanced wastewater treatment solution. The hyper-thermophilic aerobic bioreactor, operating up to 65 °C, is tailored for high organic removal, while MD efficiently produces clean water. Throughout the study, high removal rates of 99.5% for organic matter, 96.4% for ammonia, and 100% for phosphorus underscored the impressive adaptability of microorganisms to challenging hyper-thermophilic conditions and a successful combination with the MD process. Despite the extreme temperatures and substantial salinity accumulation reaching up to 12,532 μS/cm, the biomass of microorganisms increased by 1.6 times over a 92-day period, representing their remarkable resilience. The distillation flux ranged from 6.15 LMH to 8.25 LMH, benefiting from the temperature gradient in the hyper-thermophilic setting and the design of the tubular submerged MD membrane module. The system also excels in pH control, utilizing fewer alkali and nutritional resources than conventional systems. Meiothermus, Firmicutes, and Bacteroidetes, the three dominant species, played a crucial role, showcasing their significance in adapting to high salinity and decomposing organic matter., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)

This study aimed to develop an ammonia and pH super-sensitive label by incorporating methyl red and bromothymol blue (MR-BTB, MB) into gellan gum/sodium carboxymethyl cellulose (GG/CMC-Na, GC). Furthermore, E-nose as an auxiliary tool combined with the labels to monitor meat freshness. Results showed that MB had more color change than pure MR or BTB, and the detection limit of ammonia about the MR-BTB (1:2) group was only 2.82 ppm. The addition of MB significantly increased tensile strength, moisture content, and water solubility, but decreased elongation at break and transmittance of the GC label (p < 0.05). The result of FTIR and SEM indicated the formation of hydrogen bonds and well compatibility between MB and GC. Furthermore, the color of the GC-10.0MB label was constantly obviously changing during meat storage, indicating that the GC-10.0MB label had great potential for monitoring the freshness of the lamb meat. A high correlation was found between ΔE of GC-10.0MB label and TVB-N (R 2  = 0.9092) and pH (R 2  = 0.9114) of meat. Interestingly, the high correlation between ΔE of GC-10.0 MB label and the response value of S2 (R 2  = 0.7531), S6 (R 2  = 0.9921), and S7 sensor (R 2  = 0.8325) of E-nose was also found., Competing Interests: Declaration of competing interest All co-authors declare that there are no conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A fluorescent sensor array (FSA) combined with deep learning (DL) techniques was developed for meat freshness real-time monitoring from development to deployment. The array was made up of copper metal nanoclusters (CuNCs) and fluorescent dyes, having a good ability in the quantitative and qualitative detection of ammonia, dimethylamine, and trimethylamine gases with a low limit of detection (as low as 131.56 ppb) in range of 5 ∼ 1000 ppm and visually monitoring the freshness of various meats stored at 4 °C. Moreover, SqueezeNet was applied to automatically identify the fresh level of meat based on FSA images with high accuracy (98.17 %) and further deployed in various production environments such as personal computers, mobile devices, and websites by using open neural network exchange (ONNX) technique. The entire meat freshness recognition process only takes 5 ∼ 7 s. Furthermore, gradient-weighted class activation mapping (Grad-CAM) and uniform manifold approximation and projection (UMAP) explanatory algorithms were used to improve the interpretability and transparency of SqueezeNet. Thus, this study shows a new idea for FSA assisted with DL in meat freshness intelligent monitoring from development to deployment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Manufacturing processes in semiconductor and photonics industries involve the use of a significant amount of organic solvents. Recycle and reuse of these solvents produce distillate residues and require treatment before being discharged. This study aimed to evaluate the performance of the biological treatment system in a full-scale wastewater treatment plant that treats wastewater containing distillate residues from the recycling of electronic chemicals. Batch experiments were conducted to investigate the optimal operational conditions for the full-scale wastewater treatment plant. To achieve good nitrogen removal efficiency with effluent ammonia and nitrate concentrations below 20 mg N/L and 50 mg N/L, respectively, it was suggested to control the ammonia concentration and pH of the influent below 500 mg N/L and 8.0, respectively. In addition, the biodegradability of N-methylpyrrolidone, diethylene glycol monobutyl ether, and cyclopentanone distillate residues from the electronic chemicals manufacturing process were evaluated under aerobic, anoxic, and anaerobic conditions. N-methylpyrrolidone and cyclopentanone distillate residues were suggested to be treated under anoxic condition. However, substrate inhibition occurred when using cyclopentanone distillate residue as a carbon source with chemical oxygen demand (COD) levels higher than 866 mg/L and nitrate levels higher than 415 mg N/L. Under aerobic condition, the COD from both N-methylpyrrolidone and cyclopentanone distillate residues could be easily degraded. Nevertheless, a negative effect on nitrification was observed, with a prolonged lag time for ammonia oxidation as the initial COD concentration increased. The specific ammonia oxidation rate and nitrate production rate decreased under high COD concentration contributed by N-methylpyrrolidone and cyclopentanone distillate residues. Furthermore, the biodegradability of diethylene glycol monobutyl ether distillate residue was found to be low under aerobic, anoxic, and anaerobic conditions. With respect to the abundance of nitrogen removal microorganisms in the wastewater treatment plant, results showed that Comammox may have an advantage over ammonia oxidizing bacteria under high pH conditions. In addition, Comammox may have higher resistance to environmental changes. Dominance of Comammox over ammonia oxidizing bacteria under high ammonia condition was first reported in this study., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

A novel Fe 2 Mo 3 O 8 /MoO 2 @MoS 2 nanocomposite is synthesized for extremely sensitive detection of NH 3 in the breath of kidney disease patients at room temperature. Compared to MoS 2 , α-Fe 2 O 3 /MoS 2 , and MoO 2 @MoS 2 , it shows the optimal gas-sensing performance by optimizing the formation of Fe 2 Mo 3 O 8 at 900 °C. The annealed Fe 2 Mo 3 O 8 /MoO 2 @MoS 2 nanocomposite (Fe 2 Mo 3 O 8 /MoO 2 @MoS 2 -900 °C) sensor demonstrates a remarkably high selectivity of NH 3 with a response of 875% to 30 ppm NH 3 and an ultralow detection limit of 3.7 ppb. This sensor demonstrates excellent linearity, repeatability, and long-term stability. Furthermore, it effectively differentiates between patients at varying stages of kidney disease through quantitative NH 3 measurements. The sensing mechanism is elucidated through the analysis of alterations in X-ray photoelectron spectroscopy (XPS) signals, which is supported by density functional theory (DFT) calculations illustrating the NH 3 adsorption and oxidation pathways and their effects on charge transfer, resulting in the conductivity change as the sensing signal. The excellent performance is mainly attributed to the heterojunction among MoS 2 , MoO 2 , and Fe 2 Mo 3 O 8 and the exceptional adsorption and catalytic activity of Fe 2 Mo 3 O 8 /MoO 2 @MoS 2 -900 °C for NH 3 . This research presents a promising new material optimized for detecting NH 3 in exhaled breath and a new strategy for the early diagnosis and management of kidney disease., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Gas sensors based on ambipolar materials offer significant advantages in reducing the size of the analytical system and enhancing its efficiency. Here, bilayer heterojunction devices are constructed using different octafluorinated phthalocyanine complexes, with Zn and Co as metal centers, combined with a lutetium bisphthalocyanine complex (LuPc 2 ). Stable p-type behavior is observed for the ZnF 8 Pc/LuPc 2 device under both electron-donating (NH 3 ) and -oxidizing (NO 2 and O 3 ) gaseous species, while the CoF 8 Pc/LuPc 2 device exhibits n-type behavior under reducing gases and p-type behavior under oxidizing gases. The nature of majority of the charge carriers of Co-based devices varies depending on the nature of target gases, displaying an ambipolar behavior. Both heterojunction devices demonstrate stable and observable response toward all three toxic gases in the sub-ppm range. Remarkably, the Co-based device is highly sensitive toward ammonia with a limit of detection (LOD) of 200 ppb, whereas the Zn-based device demonstrates exceptional sensitivity toward oxidizing gases, with excellent LOD values of 4.9 and 0.75 ppb toward NO 2 and O 3 , respectively, which makes it one of the most effective organic heterojunction sensors reported so far for oxidizing gases.

Submerged zone in bioretention facilities for stormwater treatment has been approved to be an effective structure amendment to improve denitrification capability. However, the role and influence of water quality changes in the submerged zone under natural continuous random rainfall patterns are still not clear, especially when the rainfall is less than the pore water in the submerged zone. In this study, continuous rainfall events with different rainfall volume (light rain-light rain-heavy rain) were designed in a lab-scale woodchip mulched pyrite bioretention facility to test the effects of rainfall pattern. The results exhibited that light rain events significantly affected the pollutant removal performance of bioretention for the next rainfall. Different effects were observed during the long-term operation. In the 5th month, light rain reduced the ammonia removal efficiency of subsequent rainstorm events by 8.70%, while in the 12th month, when nitrate leakage occurred, light rain led to a 40.24% reduction in the next heavy rain event's nitrate removal efficiency. Additionally, light rain would also affect the concentration of by-products in the next rainfall. Following a light rain, the concentration of sulfate in the subsequent light rainfall can increase by 24.4 mg/L, and by 11.92 mg/L in a heavy rain. The water quality in the submerged zone and media characteristics analysis suggested that nitrogen conversion capacity of the substrate and microbes, such as Nitrospira (2.86%) and Thiobacillus (35.71%), as well as the in-situ accumulation of pollutants under light rain played important roles. This study clarifies the relationship between successive rainfall events and provides a more comprehensive understanding of bioretention facilities. This is beneficial for field study of bioretention facilities in the face of complex rainfall events., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Ammonia (NH 3 ) is the major constituent among all the reactive nitrogen species present in the atmosphere, and the most essential species for secondary inorganic aerosol formation. Recent satellite-based observations have identified the Indo-Gangetic Plain (IGP) as a major hotspot of global NH 3 emission; however, the major sources and atmospheric processes affecting its abundance are poorly understood. The present study aims to understand the wintertime sources of NH 3 over a semi-urban site (Patiala, 30.3°N, 76.4°E, 249 m amsl) located in the IGP using species specific δ 15 N in PM 2.5 . A distinct diurnal variation in the stable isotopic signature of total nitrogen (δ 15 N-TN) and ammonium (δ 15 N-NH 4 + ) were observed; although, average day and night time concentrations of TN and NH 4 + were similar. Mixing model results using δ 15 N-NH 3 reveal the dominance of non-agricultural emissions (NH 3 slip: 47 ± 24%) over agricultural emissions (24 ± 11%), combustion sources (19 ± 14 %), and biomass burning (10 ± 8%) for atmospheric NH 3 . Diurnal variability in source contributions to NH 3 was insignificant. Further, significantly negative correlations of δ 15 N-NH 4 + with ambient relative humidity (RH) and daytime NO 3 - -N concentration were observed, and attributed to the possibility of NH 4 NO 3 volatilization during day-time owing to lower RH and higher temperature, resulting in isotopic enrichment of the remaining NH 4 + in aerosol phase. This study, a first of its type from India, highlights the importance of non-agricultural NH 3 emissions over the agriculture dominated IGP region, and the role of local meteorology on the isotopic fractionation of δ 15 N in aerosol NH 4 + ., Competing Interests: Declaration of competing interest Authors declare that there is no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Ammonia‑nitrogen wastewater is one of the main pollutants in the current environment. Rapid detection of microorganisms resistant to ammonia‑nitrogen provides a basis for bioremediation of ammonia‑nitrogen contaminated sites. This study uses electrochemical analysis for efficiently detecting of ammonia-resistant bacteria, utilizing a commercially available, low-cost screen-printed electrode (SPE) modified with agarose-based hydrogel (gel) or graphene oxide (GO). At the same time, the study employed electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) to monitor bacterial growth, revealing Escherichia coli (E. coli) inhibition upon ammonia‑nitrogen addition, while Raoultella terrigena (RN1) and Pseudomonas (RN2) exhibit tolerance. The method provides sensitivity results in <45 min, which is significantly faster than traditional methods. RN1 and RN2 exhibit promising ammonia‑nitrogen removal rates, reaching up to 81 % and 92 %, respectively. This study aimed to develop an effective electrochemical method for rapidly detecting the sensitivity of microorganisms to ammonia‑nitrogen. The method offers advantages such as high speed, efficiency, and cost-effectiveness, potentially providing valuable microbial resources for mitigating ammonia nitrogen wastewater pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Mitigation of methane (CH 4 ) emissions from slurry pits within pig barns can be achieved through treatment of residual slurry left after frequent flushing of the slurry pits. In this study, dosages of additives such as sodium dodecyl sulfate (SDS) and hydrogen peroxide (H 2 O 2 ) were optimized to achieve reduction in CH 4 emissions from residual pig slurry during storage. In addition, the effects on emissions when both the treatments were combined and the effects of SDS treatment on slurry acidified with sulfuric acid (H 2 SO 4 ) were studied in order to reduce CH 4 and ammonia (NH 3 ) emissions from residual pig slurry storage. A maximum of 98% and 70% reduction in CH 4 emissions were achieved with SDS and H 2 O 2 treatments, respectively. The combination of SDS and H 2 O 2 did not increase efficiency in reducing CH 4 emissions compared to SDS treatment alone. Whereas the application of SDS to slurry acidified with H 2 SO 4 (pH 6.2) increased the CH 4 mitigation efficiency by 15-30% compared to treating slurry with only SDS. The combined treatment (SDS + H 2 SO 4 ) reduced NH 3 emissions by 20% compared to treating slurry with H 2 SO 4 (pH 6.2) alone. Hereby, combined treatment (SDS + H 2 SO 4 ) can reduce both CH 4 and NH 3 emissions, with a reduced amount of chemicals required for the treatment. Hence, application of SDS at concentrations <2 g kg -1 to acidified slurry is recommended to treat residual pig manure in pig barns., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

High quality FTIR spectra of aerosols of NH3-THF and NH3-TMO binary clathrate hydrates (CHs) have been measured. Our recently developed all-vapor sub-second approach to clathrate-hydrate formation combined with computational studies has been used to identify vibrational spectroscopic signatures of NH3 within the gas hydrates. The present study shows that there are three distinct NH3 types, namely, classical small-cage NH3, nonclassical small-cage NH3, and NH3 within the hydrate network. The network ammonia does not directly trigger the non-classical CH structure. Rather, the ammonia within the network structure perturbs the water bonding, introducing orientational defects that are stabilized by small and/or large cage guest molecules through H-bonding. This unusual behavior of NH3 within CHs opens a possibility for catalytic action of NH3 during CH-formation. Furthermore, impacts over time of the small-cage NH3-replacement molecules CO2 and CH4 on the structure and composition of the ternary CHs have been noted. [ABSTRACT FROM AUTHOR]

The potential deodorizing effects of Saccharina japonica have been evaluated by determining their deodorizing performance, but they are yet to be validated in experimental animals. The deodorizing effects of S. japonica were examined in an animal model using a novel odor marker associated with aging by comparing the concentration of odor component in urine obtained from two- and 10-month-old ICR mice using gas chromatography-mass spectrometry (GC-MS), and the changes in the trimethylamine (TMA) concentration, ammonia level, and structure of sweat gland were determined after exposing 10-month-old ICR mice to 70% ethanol extract of S. japonica (EESJ) for four weeks. In vitro analysis was performed to confirm the composition of EESJ with respect to the total flavonoid contents (TFC, 28.6 ± 2.5 mg/g), total polyphenol contents (TPC, 107.3 ± 8.9 mg/g), and total condensed tannin contents (TTC, 65.7 ± 5.2 mg/g) contents, as well as to the deodorizing performance to ammonia and acetic acid (91.2 ± 7.8% and 54.8 ± 6.3%, respectively). In vivo analysis revealed TMA to be the novel odor marker associated with aging among the 19 odor components evaluated, considering the higher concentration in the urine of 10-month-old ICR mice. The peak area of TMA on the gas chromatogram was significantly lower in the 10-month-old ICR mice treated with EESJ than in the two-month-old mice. A similar decrease was observed in the level of ammonia obtained from the dirty bedding of the EESJ-treated group. Moreover, tissues obtained from the mouse foot of the group exposed to EESJ showed a dose-dependent decrease in the gland tube number of sweat glands and the TMA dehydrogenase transcription level. Overall, these results provide novel evidence that the administration of EESJ helps reduce the body TMA and ammonia concentrations, resulting in reduced odor and a decrease in the number of sweat glands and the expression of TMA dehydrogenase in the ICR mouse feet. [ABSTRACT FROM AUTHOR]

Seafood plays a major role in the human diet. During transportation, without proper storage and supply chain, its quality deteriorates easily. The post-harvesting processes such as the storage of food play a crucial role in human health. So it is highly imperative to have a technique for identifying food spoilage earlier to ensure the food safety and security of the consumers. Herein we have developed a highly selective and sensitive fluorescent 'Turn-on' probe 2-amino-5-nitrobenzo [d] thiazol-2-yl) imino)methylphenol ANT based on aggregation induced emission (AIE). ANT molecule possesses both restricted intramolecular rotation (RIR) and excited state intramolecular proton transfer (ESIPT) properties leading to fluorescent enhancement rather than aggregation caused quenching (ACQ). The probe shows high selectivity and sensitivity towards the NH 3 vapor. This probe with the AIE property is employed for the real-time detection of NH 3 in both aqueous and gaseous phases. ANT molecule is deposited on the paper shred by a physical method is utilized to monitor NH 3 vapor from red snapper fish as a real-time sample during its degradation processes. After two days there is a ratiometric color change in the paper shred from yellow to orange for the fish stored at room temperature indicating its rotten and unpalatability nature. Paper shred is reused by immersing it into the tetrahydrofuran (THF), in which it retains its initial color due to deprotonation of NH 3 , keto to enol tautomerism discloses the reusability of the fluorescent probe. Studies carried out using UV-visible and fluorescence spectroscopy infer that the ANT probe has high affinity towards NH 3 vapor., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The nitrogen transformation during sludge pyrolysis is affected by the dewater conditioner. However, the comparative analysis of the conditioner under identical pyrolysis conditions has been previously absent. In this study, Ca-, Fe- and Al-based conditioners were selected as the representatives. A comprehensive evaluation considering the cost of the conditioners and the product characteristics was conducted. Additionally, the in-situ fixation mechanism of the conditioner on nitrogen-containing gas was concurrently revealed. Among the six conditioners, CaO and AlCl 3 were identified as the top performers, ranking first and second, respectively. Furthermore, Fe/Ca-based conditioners reduced NH 3 and HCN release by 1.5 ∼ 5.53 % and 0 ∼ 1.55 %, respectively, by facilitating the conversion of amine-N to a more stable form in condensable fraction. Fe promoted volatile amine-N cyclization, while Ca encouraged its dehydrogenation. Both Fe/Ca-based conditioners increased 7.5 ∼ 14.8 % nitrogen retention in char, by inhibiting the decomposition of protein-N. Al-based conditioners had little effect on NH 3 and HCN, but contributed to 2.3 ∼ 2.8 % production of stabilized nitrogen in char. The introduction of Cl in Fe/Ca/Al chloride conditioners would promote the decomposition of inorganic ammonium salts to produce NH 3 at 30 ∼ 185 °C. And Cl also reacted with volatiles through electrophilic substitution reaction, leading to the formation of halogenated hydrocarbons in condensable fraction and the release of more NH 3 , HCN, and HNCO at 30 ∼ 465 °C. The findings of this study provide a detailed comparative analysis of various conditioners under uniform conditions and reveal the in-situ fixation mechanism of nitrogen-containing gas. This will provide guidance for the sludge conditioning-dewatering-drying integrated treatment and disposal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Breath analysis enables rapid, noninvasive diagnosis of human health by identifying and quantifying exhaled biomarker. Here, we demonstrated an exhaled breath sensing method using the near-infrared laser spectroscopy, and sub parts-per-million (ppm) level ammonia detection inside the exhaled gas was achieved employing a distributed feedback laser centered at 1512 nm and Kalman filtering algorithm. Integration of the ammonia sensor was realized for exhaled breath analysis of kidney patients, and a dual operation mechanism with static and dynamic modes was proposed to make this method applicable for real-time and comprehensive pre-diagnosis of kidney disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

With stringent regulations of internal combustion engine on reducing CO 2 emission, ammonia has been used as an alternative fuel. Investigating how engine-related performance is affected by partial ammonia replacement of diesel fuel is essential for understanding the combustion. Therefore, in this study, a three-dimensional numerical simulation model is developed for the burning of two fuels of diesel and ammonia based on relevant parameters (i.e., compression ratio, load, ammonia energy fraction, etc.) in a lab-made diesel engine. The consequences of load and compression proportion on combustion and pollutant emissions are investigated for ammonia energy fractions between 50% and 90%. When the ammonia portion rises, the increased ammonia equivalent ratio causes ammonia to move away from the dilute combustion boundary and accelerates the combustion rate of ammonia. An increase in compression ratio significantly increases the specified thermal performance and combustion efficacy. When the compression ratio is 16, as the ammonia energy fractions increases, due to the increase in the proportion of ammonia, that is, the proportion of nitrogen atoms increases, more NOx is generated during the combustion process. When the ammonia substitution rate is 90%, as the compression ratio increases, the cylinder pressure and temperature increase. The combustion efficiency of ammonia increases, generating more NOx and NOx emissions can reach 0.66 mg/m 3 . At a compression ratio of 18, the NOx emissions can reach 1.59 mg/m 3 . However, under medium and low load conditions, as the ammonia fraction increases, the total energy of fuel decreases, and the combustion efficiency of ammonia decreases, resulting in a decrease in the heat released during combustion and a decrease in NOx emissions. When the ammonia substitution rate is 90% and the load is 25%, NOx emissions reach 0.1 mg/m 3 . This research provides theoretical suggestions for the profitable and use ammonia fuel in internal combustion engines in a clean manner., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The amounts of gases emitted from composting are key to evaluating global warming potential (GWP). However, few methods can accurately predict the quantities of relevant gas emissions. In this study, three developed machine-learning models were used to predict NH 3 emissions and GWP. The extreme gradient boosting model provided the best predictions (R 2  > 90 %) compared to random forest, making it a suitable method for calculating NH 3 emissions and GWP. The k-nearest neighbor classification model was utilized to determined compost maturity achieving 92 % accuracy. Shapley Additive ExPlanation analysis was applied to identify key factors influencing gas emissions and maturity. Aeration rate, carbon-to-nitrogen ratio and moisture content showed high importance in decreasing order for predicting NH 3 emissions, while NO 3 - was the most significant factor for predicting GWP. Practical applications of predictive models suggested that prediction of GWP was 792614 Mg CO 2e year -1 close to annual calculation of 789000 Mg CO 2e year -1 in California., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Seasonal and daily variations of gaseous emissions from naturally ventilated dairy cattle barns are important figures for the establishment of effective and specific mitigation plans. The present study aimed to measure methane (CH 4 ) and ammonia (NH 3 ) emissions in three naturally ventilated dairy cattle barns covering the four seasons for two consecutive years. In each barn, air samples from five indoor locations were drawn by a multipoint sampler to a photoacoustic infrared multigas monitor, along with temperature and relative humidity. Milk production data were also recorded. Results showed seasonal differences for CH 4 and NH 3 emissions in the three barns with no clear trends within years. Globally, diel CH 4 emissions increased in the daytime with high intra-hour variability. The average hourly CH 4 emissions (g h -1 livestock unit -1 (LU)) varied from 8.1 to 11.2 and 6.2 to 20.3 in the dairy barn 1, from 10.1 to 31.4 and 10.9 to 22.8 in the dairy barn 2, and from 1.5 to 8.2 and 13.1 to 22.1 in the dairy barn 3, respectively, in years 1 and 2. Diel NH 3 emissions highly varied within hours and increased in the daytime. The average hourly NH 3 emissions (g h -1  LU -1 ) varied from 0.78 to 1.56 and 0.50 to 1.38 in the dairy barn 1, from 1.04 to 3.40 and 0.93 to 1.98 in the dairy barn 2, and from 0.66 to 1.32 and 1.67 to 1.73 in the dairy barn 3, respectively, in years 1 and 2. Moreover, the emission factors of CH 4 and NH 3 were 309.5 and 30.6 (g day -1  LU -1 ), respectively, for naturally ventilated dairy cattle barns. Overall, this study provided a detailed characterization of seasonal and daily gaseous emissions variations highlighting the need for future longitudinal emission studies and identifying an opportunity to better adequate the existing mitigation strategies according to season and daytime., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Smart packaging material capable of real-time monitoring of food freshness is essential for ensuring food safe. At present, colorimetric ammonia-sensing smart film often possesses issues with complicated production, high cost, and inferior long-term colour stability. Herein, Zinc‑copper bimetallic organic framework (ZnCu-BTC, BTC = 1,3,5-benzenetricarboxylate acid) nanorods with colorimetric ammonia-responsiveness were synthesized by adopting facile aqueous solution method, which were then explored as nano inclusions in potato starch/polyvinyl alcohol (PS/PVA) composite film towards developing high-performance smart packaging material. The results demonstrated that the introduction of ZnCu-BTC nanorods within PS/PVA brought about remarkable improvement in blend compatibility, accompanied by a boost in tensile strength to 47.2 MPa, as well as enhanced ultraviolet (UV) blocking efficacy (over 95.0 %). Additionally, the barrier properties of PS/PVA film against water vapor and oxygen were fortified due to the addition of ZnCu-BTC. More importantly, the developed PS/PVA/ZnCu-BTC nanocomposite film displayed satisfactory antibacterial activity (over 99 %) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), favorable colorimetric ammonia-sensing ability, and long-term colour stability. The ZnCu-BTC incorporated PS/PVA nanocomposite film could grant real-time detection of prawn freshness decline via remarkable colour change, indicating vast promise for smart food packaging applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ammonia is a colorless gas, yet it can be fatal if inhaled or ingested in high enough concentrations. Herein, a solid-state colorimetric smart wool (WL) sensor for ammonia was developed. Common hop (Humulus lupulus L.) is a natural resource of spectroscopical dyestuff known as xanthohumol (XN). Wool fabrics were dyed with different concentrations of xanthohumol extract using the high-temperature high-pressure method in the presence of a mordant. The coloration parameters and absorption spectra were employed to explore the yellow-to-white colorimetric shift of the wool fabric after it was exposed to aqueous ammonia. The wool fabric showed an excellent detection limit of 5 to 125 ppm. When the ammonia concentration was increased, the absorbance spectra demonstrated a hypsochromic shift from 498 nm to 367 nm. This could be attributed to changes in the molecular structure of xanthohumol that happen owing to intramolecular charge delocalization. Using transmission electron microscopy (TEM), the mordant/xanthohumol nanoparticles were measured to have diameters of 15-40 nm. The xanthohumol-finished wool fabrics showed good colorfastness properties. The incorporation of mordant/xanthohumol nanoparticles into wool fabrics showed no negative effects on their stiffness or air-permeability., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A fluorescent hybrid film composed of nitrogen-doped graphene quantum dots (N-GQDs) loaded on halloysite nanotubes (HNTs) (N-GQDs/HNTs nanocomposite) as a sensitive element and polyvinyl alcohol (PVA) as a film-forming matrix was designed for freshness detection. The PVA-N-GQDs/HNTs hybrid film exhibited significantly enhanced fluorescence attributed to the loading of N-GQDs onto the surface of HNTs through electrostatic interactions and hydrogen bonding, effectively reducing their aggregation. The fluorescence of the hybrid film could be quenched by ammonia via photoinduced electron transfer (PET), with good linearity in the range of 20 ppm to 500 ppm ammonia and a limit of detection (LOD) of 0.63 ppm. In addition, the hybrid film was applied to monitor the freshness of seawater fish and freshwater fish stored at refrigeration and room temperature to evaluate the practicality of this approach. The developed hybrid film showed promise for nondestructive and on-site monitoring of fish spoilage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Storing manure emits greenhouse gas (GHG) emissions, including nitrous oxide (N 2 O) and methane (CH 4 ). However, the emissions from types of manure stored at smallholder dairy farms remains unknown. Hence, the study aims to analyse the dynamics of N 2 O and CH 4 from different types of dairy manure as affected by storage periods. We collected samples from fresh manure (FM-DF1), manure from communal ponds in an urban dairy farm (IP-DF1, FP-DF1, MS-DF1), fresh manure from an urban dairy farm (FM-DF2), and fresh (FM-DF3), separated (FS-DF3), and fermented manure (FR-DF3) from a peri-urban dairy farm, and stored them for eight weeks and analyse them using the closed chamber method. The changes of manure composition including total solids (TS), nitrogen (N), ammonia-nitrogen (N-NH 3 ), and carbon (C) were analysed. Results indicated an increase TS in all treatments except for MS-DF1, while N, N-NH 3 , and C content decreased in all treatments. The N 2 O emissions formed at the start, peaked in the middle, and declined towards the end storage period. The CH 4 emissions peaked at the start and decreased until the end storage period. Treatment FM-DF2 yield highest cumulative of N 2 O (0.82 g/m 2 ) and CH 4 (41.63 g/m 2 ) compared to other fresh manure treatment. A mixed model analysis detected a significant interaction (p < 0.05) between manure types and storage periods. In conclusion, manure types and storage periods affect the emissions. Changes in manure concentration during storage and animal diets are two important factors influencing emissions. Strategies to reduce emissions include reducing moisture content in manure, shortening storage periods, and improving feed quality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Chemiresistive polymer-based sensors are promising platforms for monitoring various gases and volatile organic compounds. While they offer appealing attributes, such as ease of fabrication, flexibility, and cost-effectiveness, most of these sensors have a nearly identical response to cross-reactive gases, such as ammonia (NH 3 ) and carbon dioxide (CO 2 ). Aiming to address the shortcomings of chemiresistive polymer-based sensors in selectivity and simultaneous measurements of cross-reactive gases, a chemiresistive sensor array was developed consisting of components sensitive to carbon dioxide and ammonia as well as a control segment to provide the baseline. The designed system demonstrated a wide detection range for both ammonia (ranging from 0.05 to 1000 ppm) and carbon dioxide (ranging from 10 3 to 10 6 ppm) at both room and low temperatures (e.g., 4 °C). Our results also demonstrate the ability of this sensor array for the simultaneous detection of carbon dioxide and ammonia selectively in the presence of other gases and volatile organic compounds. Finally, the array was used to monitor CO 2 /NH 3 in real food samples to demonstrate the potential for real-world applications.

Wearable gas sensors have drawn great attention for potential applications in health monitoring, minienvironment detection, and advanced soft electronic noses. However, it still remains a great challenge to simultaneously achieve excellent flexibility, high sensitivity, robustness, and gas permeability, because of the inherent limitation of widely used traditional organic flexible substrates. Herein, an electrospinning polyacrylonitrile (PAN) nanofiber network was designed as a flexible substrate, on which an ultraflexible wearable gas sensor was prepared with in situ assembled polyaniline (PANI) and multiwalled carbon nanotubes (MWCNTs) as a sensitive layer. The unique nanofiber network and strong binding force between substrate and sensing materials endow the wearable gas sensor with excellent robustness, flexibility, and gas permeability. The wearable sensor can maintain stable NH 3 sensing performance while sustaining extreme bending and stretching (50% of strain). The Young's modulus of wearable PAN/MWCNTs/PANI sensor is as low as 18.9 MPa, which is several orders of magnitude smaller than those of reported flexible sensors. The water vapor transmission rate of the sensor is 0.38 g/(cm 2 24 h), which enables the wearing comfort of the sensor. Most importantly, due to the effective exposure of sensing sites as well as the heterostructure effect between MWCNTs and PANI, the sensor shows high sensitivity to NH 3 at room temperature, and the theoretical limit of detection is as low as 300 ppb. This work provides a new avenue for the realization of reliable and high-performance wearable gas sensors.

Exposure to high concentrations of odours can result in health effects associated with direct health risks and irritation from nuisance. This investigation aimed to correlate aspects of the waste composting process with the emission levels of malodourous compounds. An essential optimisation criterion is the reduction of negative environmental impacts, particularly odour emissions. This study characterises odour concentration variations across various technological variants over different weeks of the composting process. A secondary objective is evaluating the efficacy of these variants, which differ in inoculation substances and compost heap composition. Olfactometric analyses were conducted using portable field olfactometers, enabling precise dilutions by mixing contaminated and purified air. The primary aim was to examine the correlation between selected odour parameters, determined via sensory analysis, and ammonia concentration during different composting weeks. Ammonia levels were measured using an RAE electrochemical sensor. Research shows that odour concentration is a significant indicator of compost maturity. In situ, olfactometric testing can effectively monitor the aerobic stabilisation process alone or with other methods. The most effective technological solution was identified by combining olfactometric and ammonia measurements and monitoring composting parameters, ensuring minimal odour emissions and the safety of employees and nearby residents.

A new type of carbonized polymer dot was prepared by the one-step hydrothermal method of triethoxylsilane (TEOS) and citric acid (CA). The sensor made from carbonized polymer dots (CPDs) showed superior gas sensing performance toward ammonia at room temperature. The Si, O-codoped CPDs exhibited superior ammonia sensing performance at room temperature, including a low practical limit of detection (pLOD) of 1 ppm ( R a / R g : 1.10, 1 ppm), short response/recovery time (30/36 s, 1 ppm), high humidity resistance (less than 5% undulation when changing relative humidity to 80 from 30%), high stability (less than 5% initial response undulation after 120 days), reliable repeatability, and high selectivity against other interferential gases. The gas sensing mechanism was investigated through control experiments and in situ FTIR, indicating that Si, O-codoping essentially improves the electron transfer capability of CPDs and synergistically dominates the superior ammonia sensing properties of the CPDs. This work presents a facile strategy for constructing novel high-performance, single-component carbonized polymer dots for gas sensing.

Organic and inorganic hybrid field-effect transistors (FETs), utilizing layered molybdenum diselenide (MoSe 2 ) and an organic semiconductor poly(3-hexylthiophene) (P3HT), are presented for biosensing applications. A new hybrid device structure that combines organic (P3HT) and inorganic (MoSe 2 ) components is showcased for accurate and selective bioanalyte detection in human bodily fluids to overcome 2D-transition metal dichalcogenides (TMDs) nonspecific interactions. This hybrid structure utilizes organic and inorganic semiconductors' high surface-to-volume ratio, carrier transport, and conductivity for biosensing. Ammonia concentrations in saliva and plasma are closely linked to physiological and pathological conditions of the human body. A highly sensitive hybrid FET biosensor detects total ammonia (NH 4 + and NH 3 ) from 0.5 μM to 1 mM concentrations, with a detection limit of 0.65 μM in human bodily fluids. The sensor's ammonia specificity in artificial saliva against interfering species is showcased. Furthermore, the fabricated hybrid FET device exhibits a stable and repeatable response to ammonia in both saliva and plasma, achieving a remarkable response level of 2300 at a 1 mM concentration of ammonia, surpassing existing literature by 10-fold. This hybrid FET biosensing platform holds significant promise for developing a precise tool for the real-time monitoring of ammonia concentrations in human biological fluids, offering potential applications in point-of-care diagnostics.

This study aimed to fabricate and characterize a novel colorimetric indicator designed to detect ammonia (NH 3 ) and monitor meat freshness. The sensing platform was constructed using electrospun nanofibers made from polylactic acid (PLA), which were then impregnated with anthocyanins as a natural pH-sensitive dye, extracted from red cabbage. This research involved investigating the relationship between the various concentrations of anthocyanins and the colorimetric platform's efficiency when exposed to ammonia vapor. Scanning electron microscope (SEM) results were used to examine the morphology and structure of the nanofiber mats before and after the dip-coating process. The study also delved into the selectivity of the indicator when exposed to various volatile organic compounds (VOCs) and their stability under extreme humidity levels. Furthermore, the platform's sensitivity was evaluated as it encountered ammonia (NH 3 ) in concentrations ranging from 1 to 100 ppm, with varying dye concentrations. The developed indicator demonstrated an exceptional detection limit of 1 ppm of MH 3 within just 30 min, making it highly sensitive to subtle changes in gas concentration. The indicator proved effective in assessing meat freshness by detecting spoilage levels in beef over time. It reliably identified spoilage after 10 h and 7 days, corresponding to bacterial growth thresholds (10 7 CFU/mL), both at room temperature and in refrigerated environments, respectively. With its simple visual detection mechanism, the platform offered a straightforward and user-friendly solution for consumers and industry professionals alike to monitor packaged beef freshness, enhancing food safety and quality assurance.

Composting has emerged as a suitable method to convert or transform organic waste including manure, green waste, and food waste into valuable products with several advantages, such as high efficiency, cost feasibility, and being environmentally friendly. However, volatile organic compounds (VOCs), mainly malodorous gases, are the major concern and challenges to overcome in facilitating composting. Ammonia (NH 3 ) and volatile sulfur compounds (VSCs), including hydrogen sulfide (H 2 S), and methyl mercaptan (CH 4 S), primarily contributed to the malodorous gases emission during the entire composting process due to their low olfactory threshold. These compounds are mainly emitted at the thermophilic phase, accounting for over 70% of total gas emissions during the whole process, whereas methane (CH 4 ) and nitrous oxide (N 2 O) are commonly detected during the mesophilic and cooling phases. Therefore, the human health risk assessment of malodorous gases using various indexes such as ECi (maximum exposure concentration for an individual volatile compound EC), HR (non-carcinogenic risk), and CR (carcinogenic risk) has been evaluated and discussed. Also, several strategies such as maintaining optimal operating conditions, and adding bulking agents and additives (e.g., biochar and zeolite) to reduce malodorous emissions have been pointed out and highlighted. Biochar has specific adsorption properties such as high surface area and high porosity and contains various functional groups that can adsorb up to 60%-70% of malodorous gases emitted from composting. Notably, biofiltration emerged as a resilient and cost-effective technique, achieving up to 90% reduction in malodorous gases at the end-of-pipe. This study offers a comprehensive insight into the characterization of malodorous emissions during composting. Additionally, it emphasizes the need to address these issues on a larger scale and provides a promising outlook for future research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The application of numeric modelling for determining the impact of landfills needs for reliable emission source data. In this study, a methodology for the characterization of the emission profiles of the different sources present in landfills for emission factors determination, applying an indirect methodology, is presented. Ambient air concentrations of volatile organic compounds (VOCs), hydrogen sulphide (H 2 S) and ammonia (NH 3 ) were determined in three potentially emission sources in Can Mata landfill (Hostalets de Pierola, Catalonia, Spain): dumping areas, pre-closed zone and leachate reservoir as well as in biogas, for the determination of emission factors. Multi-sorbent bed and Tenax TA tubes were used for a wide range of VOCs sampling, and analysis was conducted through TD-GC/MS. H 2 S and NH 3 were sampled and analysed using Radiello passive samplers. The highest total VOC (TVOC) concentrations were found in dumping areas (0.7-3.5 mg m -3 ), followed by leachate reservoir (0.3-0.6 mg m -3 ) and pre-closed area (77-165 μg m -3 ). On the other hand, the highest H 2 S and NH 3 concentrations were found in leachate reservoir, presenting values of 0.8-1.1 mg m -3 and 1.7-1.8 mg m -3 , respectively. With the application of odour thresholds to the concentrations obtained, the most critical compounds regarding odour annoyances were determined. The highest odour units (O.U.) were found in leachate reservoir due to H 2 S concentrations, whereas VOCs contributed mainly to O.U. in the dumping areas. The obtained ambient air concentrations were used for the indirect determination of the emission factors through numerical modelling using a Eulerian dispersion model. The emission factors obtained for the landfill for TVOC, H 2 S and NH 3 were in the range of 0.44-10.9 g s-1, 0.16-1.02 g s -1 and 0.23-1.82 g s -1 , respectively, depending on the emission source. Reliable emission factors are crucial to obtain landfill impact maps, which are essential for the correct management of these facilities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)