Ammonia Concentration Research Articles

Temporal change of urea biochemical transformations and temperature sensitivity of ammonia volatilization in soil textural classes in the brazilian Cerrado

IntroductionSoil biochemical transformation of urea has important impacts on nitrogen (N) use efficiency in agricultural systems and environmental pollution, mainly due to N losses through ammonia volatilization (AV).MethodsThe present study aimed to evaluate and model the biochemical transformation of urea and ammonia volatilization in response to different urea doses and temperature conditions over time in sandy loam (SL) and sandy clay loam (SCL) soils in the Brazilian Cerrado. Soil mesocosm experiments were conducted with the addition of 0.25% and 0.50% urea mixed into soils (100 g dry soil) and incubated at 20°C, 25°C, 30°C, and 35°C for six days.ResultsUrease activity increased rapidly on the first day of incubation, with the highest values occurring at the 0.50% urea dose and 25°C. However, there were no significant differences in activity between soils. Soil pH ranged from 8.2 to 8.6 and was not affected by soil type, temperature, or applied doses. Soil ammonium concentration was higher at the 0.50% urea dose and in SCL soil, and it was not affected by temperature conditions. AV increased with the rise in urea dose and temperature, with SL showing higher AV values than SCL. SL also demonstrated greater temperature sensitivity than SCL.DiscussionThe regression equation models used were efficient in demonstrating the parameters of biochemical transformations and AV in both soils. The N losses through AV may be greater than 60% in sandy soils and less than 30% in clay soils.

Environmental Factors Determining the Distribution Pattern of Chironomidae in Different Types of Freshwater Habitats

Chironomidae are characterised by cosmopolitan distribution, high abundance and diversity in different aquatic environments, which makes them ideal for studying changes in freshwater ecosystems. To understand the environmental factors influencing chironomid communities, we analysed how altitude and waterbody type (hydromorphological features) affect their composition at 75 study sites from 49 watercourses. A total of 110 chironomid taxa from five subfamilies were identified, with Prodiamesa olivacea, Rheocricotopus fuscipes and Cricotopus bicinctus being the most frequent species. The lowest values of all alpha diversity components were recorded in communities collected from watercourses at altitudes up to 500 m a.s.l., while the highest values were observed in small mountainous rivers and streams. Beta diversity showed that taxa turnover was the dominant component in all situations analysed. Communities in large rivers with fine substrate were characterised by the lowest taxa turnover and the highest levels of nestedness, indicating the existence of an ecological gradient that reduces the number of taxa from one site to another. We identified indicator taxa for different altitudes, as well as groups of taxa that are typical for different waterbody types. Furthermore, the combination of four water parameters (oxygen saturation, conductivity, concentration of ammonium and nitrates) had the strongest influence on the chironomid community composition in the studied watercourses.

Synergistic Purification of Flue Gas from Straw Combustion Using Ammonia Method and Electrostatic Charged Spray

To enhance the efficiency of flue gas purification from straw combustion, a combined approach using the ammonia method and electrostatic charged spray was investigated. This study investigated the charging characteristics of atomized droplets and their impact on flue gas purification. The results show that the charge-to-mass ratio of droplets increases and then decreases as charging voltages increase. At a constant voltage, the ratio increases with higher ammonia concentrations and shows a gradual increase with higher spray pressures. For flue gases from three common straw combustion sources, the average dust removal rate at 8 kV was 2.5 to 3 times higher than at 0 kV. Under the 8 kV condition with a 10% ammonia solution, the NO removal rate was approximately 4.7 times, and the NO2 removal rate was 2.8 times compared to water alone. Particulate matter, NO, and NO2 removal rates were 61.2%, 88.6%, and 88.1%, respectively, at a spray pressure of 0.5 MPa, 8 kV charging voltage, and 10% ammonia concentration. This study provides an experimental foundation for developing high-efficiency flue gas purification systems for straw combustion.

Nasopharyngeal microbiota is influenced by agricultural air pollution in individuals with and without COPD

Respiratory health in chronic obstructive pulmonary disease (COPD) is influenced by environmental factors such as air pollution, yet the role of the airway microbiota in this relationship remains unclear. We investigated the association between exposure to air pollution from livestock farms and the nasopharyngeal microbiota in individuals with COPD compared to healthy control subjects. The study included nasopharyngeal swabs from 186 currently non-smoking participants in the Netherlands, including 65 individuals with COPD and 121 without from a regional rural cohort. Additionally, 116 individuals from a population-wide cohort were included as national controls. Samples were taken at three time points over 12 weeks. The nasopharyngeal microbiota was studied using 16 S rRNA gene-based sequencing for all baseline samples and a random selection of 6-weeks and 12-weeks samples. Dispersion models were used to determine the average concentrations of livestock-related PM10, endotoxin, and ammonia at the participants’ home addresses. Individuals with COPD had a higher absolute abundance of anaerobic bacteria, such as Peptoniphilus, Anaerococcus, Finegoldia magna, and Prevotella. Importantly, residential exposure to ammonia was identified as the most important driver of the microbial community composition, explaining 6.6% of the variation in nasopharyngeal microbiota in individuals with COPD. Higher ammonia concentrations were associated with decreased levels of key commensals and increased abundance of anaerobic bacteria. Furthermore, individuals living in areas with high livestock density exhibited greater microbial diversity compared to the broader national population. The study highlights the influence of residential exposure to livestock-related air pollution, particularly ammonia, on nasopharyngeal microbiota composition in individuals with COPD. Our findings suggest that environmental factors significantly impact microbial communities and underscore the potential role of anaerobic bacteria in COPD pathology. Future research should further investigate the mechanisms by which environmental air pollutants affect microbial communities and explore potential interventions to mitigate their effects on respiratory health.

Pharmaceutical micropollutants removal and N2O production by nitrification process in SBR and SBBR: a review.

Pharmaceutical micropollutants (PMPs) can cause significant environmental risks, with trace levels of exposure harming humans and wildlife. Biotransformation is a high-potential and low-cost way to remove PMPs, where ammonia-oxidizing microorganisms (AOM) are essential for eliminating pharmaceutical micropollutants. On the other hand, AOM are associated with nitrous oxide (N2O) emission generation in nitrifying. In this sense, micropollutants can inhibit the activity of AOB, reducing the ammonia oxidation rate and increasing N2O emissions. To mitigate these challenges, systems that allow satisfactory performance of the metabolism of AOB and NOB, such as the Sequencing Batch Reactor (SBR) and Sequencing Batch Biofilm Reactor (SBBR), are essential. However, no systematic review of the advances or gaps in this field has been published, mainly focused on SBR or SBBR. Thus, this work reviews recent advances regarding PMP biotransformation and N2O production by AOM, emphasizing SBR and SBBR systems. Besides, we compare the removal performances of various micropollutants in biological processes. The biotransformation of emerging pollutants was also presented to explore the metabolic pathways of N2O production and the critical factors that influence N2O emissions in biological processes. Controlling DO levels, intermittent aeration, and maintaining low ammonium concentrations can help mitigate N2O emissions. The simultaneous removal of PMPs and N2O emissions was also analyzed; however, there is still limited research regarding the effect of PMPs on N2O emission production in the nitrification process using SBR or SBBR. However, SBBRs may provide a more stable platform for both PMP removal and minimized emissions, mainly when biofilm characteristics and intermittent aeration are well managed. Thus, this review gives a complete vision of the advances of SBR and SBBR to remove PMPs and minimize the N2O, as well as the future directions that research needs to address to improve the PMPs biotransformation and N2O minimization.

Metabolic Response of Black Tiger Shrimp (Penaeus monodon) to Acute Ammonia Nitrogen Stress

High concentrations of ammonia nitrogen could result in the death of aquatic animals and cause a huge economic loss in the aquaculture industry. However, the metabolic responses to acute ammonia nitrogen stress remain largely unknown in Penaeus monodon. In this study, we first investigated the histological change in tissues in Penaeus monodon under 96 h acute ammonia nitrogen stress. The result of the paraffin section showed that acute ammonia nitrogen stress induced severe epithelial detachment and lumen dilatation of the hepatopancreas, swollen and hemocyte infiltration of the gills, and mucosa exfoliation and shortened villi of the intestine in Penaeus monodon, suggesting the impairment of the normal physiological function in these tissues. We next examined the change in the metabolic product in the plasma and the enzyme activity in the hepatopancreas after ammonia nitrogen stress. Upon ammonia stress, both the concentration of ammonia and urea nitrogen significantly increased, while there was no significant increase in the concentration of uric acid, which is consistent with the results that the enzyme activity of glutamine synthetase (GS), glutamate dehydrogenase (GDH), and aspartate transaminase (GOT) became significantly elevated and the enzyme activity of adenosine deaminase (ADA) in the purine metabolism pathway significantly decreased after ammonia stress, suggesting that shrimp could convert excessive ammonia to urea for ammonia detoxification through the ammonia–nitrogen metabolism pathways. Interestingly, we also observed a significant increase in superoxide dismutase (SOD) activity, suggesting a potential role of this antioxidant enzyme in the clearance of reactive oxygen species (ROS) induced via ammonia stress. Moreover, we found that acute ammonia nitrogen stress inhibited the enzyme activity of caspase 3 and caspase 8, suggesting an important role of apoptosis in protecting Penaeus monodon against acute ammonia stress. Overall, our findings revealed that Penaeus monodon may employ metabolic and purine pathways and undergo oxidative stress and apoptosis for ammonia detoxification under ammonia nitrogen stress, thus providing new insight into the metabolic response of shrimp to acute ammonia stress.

Ammonia Synthesis Loop: A Dynamic Simulation‐Based HAZOP Study

ABSTRACTAmmonia (NH₃) is a crucial industrial chemical used mostly in agriculture, with a global production of approximately 150 million metric tons by 2023. Despite its significance, ammonia manufacturing poses significant safety risks because of its high pressure, hydrogen content, and potential for hazardous accidents. To improve the safety analysis of ammonia synthesis, this study uses a dynamic simulation with Honeywell UniSim Design software. The simulation models the dynamic behavior of a 1000 TPD ammonia synthesis loop, based on the Haber‐Bosch process, at the Fertilizers and Chemicals Travancore Limited plant in Udyogamandal, Kerala, India. This study evaluated two primary risk scenarios: leakage in the ammonia synthesis pipeline and abnormal liquid levels in the ammonia separator, using dynamic simulation‐based Hazard and Operability Analysis (HAZOP). These results suggest that high liquid levels in the separator can cause liquid ammonia entrainment, compressor failure, and toxic leakage in the event of equipment failure. The pipeline leakage study points out the possibility of explosions and ammonia poisoning, with ammonia concentrations exceeding hazardous levels within minutes. This dynamic simulation‐based method provides important insights for process safety management in industrial ammonia production by better identifying risks and quantifying safety concerns than traditional steady‐state models.

Combined inhibition of anaerobic digestion by sulfate, salinity, and ammonium: potential inhibitory factors in forward osmosis-concentrated municipal wastewater.

Combined inhibition of anaerobic digestion by sulfate, salinity, and ammonium: potential inhibitory factors in forward osmosis-concentrated municipal wastewater.

In vitro assessment of the effect of free amino acids on ruminal fermentation and 15N enrichment of ruminal nitrogen pools.

In vitro assessment of the effect of free amino acids on ruminal fermentation and 15N enrichment of ruminal nitrogen pools.

Understanding sediment nutrient cycling in a hypersaline coastal lagoon using hydrogel-based passive sampling techniques.

The Coorong, South Australia, is a Ramsar-listed hypersaline coastal lagoon system of significant ecological and cultural importance. Despite facing environmental challenges such as reduced river flow and eutrophication, there is limited knowledge of organic matter fate and nutrient cycling in this system. Understanding nutrient movement and transformation within the Coorong is crucial for effective ecosystem management. This study applied diffusive equilibrium in thin films (DET) and diffusive gradient in thin films (DGT) techniques to measure dissolved nutrients (ammonium and phosphate), dissolved ferrous iron, and sulfide in sediment porewaters across a strong salinity gradient. Sampling sites were selected to capture different environmental conditions, including areas colonised by microphytobenthos and the aquatic macrophyte Ruppia tuberosa (hereafter called Ruppia). Concentration profiles were examined in both light and dark conditions to assess biotic influences on nutrient dynamics and sediment redox conditions. Sediment porewaters in deeper sites of the South Lagoon exhibited high ammonium (941-1718μmol/L), phosphate (83-171μmol/L), and sulfide (66-79μmol/L) concentrations, with negligible nitrate, indicating highly anoxic conditions unsuitable for most benthic fauna. Shallow sediments showed varying concentrations of ammonium, phosphate, dissolved ferrous iron, and sulfide across different sites and depths, influenced by Ruppia and microphytobenthos. The site colonised by Ruppia contained the lowest porewater ammonium concentrations (∼30μmol/L), suggesting that macrophyte presence can mitigate nutrient buildup in sediments. These findings indicate that sediment quality and nutrient cycling in the South Lagoon may be improved by enhancing the presence and biomass of aquatic macrophytes and macroinvertebrates.

Prediction of landfill gases concentration based on Grey Wolf Optimization - Support Vector Regression during landfill excavation process.

Prediction of landfill gases concentration based on Grey Wolf Optimization - Support Vector Regression during landfill excavation process.

Copper Alloy & Stainless Steel Corrosion in Drinking Water

Degradation of copper alloys in water distribution systems causes concern, as metal ion release may affect water taste and human health in high concentrations. Therefore, materials with improved corrosion resistance are needed. The corrosion behaviors of phosphor bronze (C52100/CW453K), Se-Bi [selenium and bismuth] brass (C89520), and stainless steel (S31600) were investigated and compared to brass (C27453/CW511L) in drinking water with varying contents of chloride, ammonia, and chlorine by potentiodynamic polarization curves. Copper alloy flowmeters were installed in a flow test setup to investigate flow-induced corrosion.

Effects and health risk assessments of different spray disinfectants on microbial aerosols in chicken houses.

Effects and health risk assessments of different spray disinfectants on microbial aerosols in chicken houses.

Nitrous oxide emissions treating hypersaline wastewater in suspended and attached partial nitritation - anammox reactors.

Nitrous oxide emissions treating hypersaline wastewater in suspended and attached partial nitritation - anammox reactors.

Hormonal and histopathological alterations in Nile tilapia, Oreochromis niloticus exposed to sublethal concentrations of ammonia

Hormonal and histopathological alterations in Nile tilapia, Oreochromis niloticus exposed to sublethal concentrations of ammonia

Multiomics-based analysis of the mechanism of ammonia reduction in Sphingomonas

Ammonia is the primary component of malodorous substances in chicken farms. Currently, the microbial ammonia reduction is considered a potential method due to its low cost, high safety, and environmental friendliness. Sphingomonas sp. Z392 can significantly reduce the ammonia level in broiler coops. However, the mechanisms of ammonia nitrogen reduction by Sphingomonas sp. Z392 remain unclear. To explore the mechanisms of ammonia reduction by Sphingomonas sp. Z392, the transcriptome and metabolome analysis of Sphingomonas sp. Z392 under high ammonium sulfate level were conducted. It was found that the transcription levels of genes related to purine metabolism (RS01720, RS07605, purM, purC, purO) and arginine metabolism (glsA, argB, argD, aguA, aguB) were decreased under high ammonium sulfate environment, and the levels of intermediate products such as ornithine, arginine, IMP, and GMP also were also decreased. In addition, the ncd2 gene in nitrogen metabolism was upregulated, and intracellular nitrite content increased by 2.27 times than that without ammonium sulfate. These results suggested that under high ammonium sulfate level, the flux of purine and arginine metabolism pathways in Sphingomonas sp. Z392 might decrease, while the flux of nitrogen metabolism pathway might increase, resulting in increased nitrite content and NH3 release. To further verify the effect of the ncd2 gene on ammonia removal, ncd2 was successfully overexpressed and knocked out in Sphingomonas sp. Z392. ncd2 Overexpression exhibited the most ammonia reduction capability, the ammonia concentration of ncd2 overexpression group decreased by 43.33% than that of without Sphingomonas sp. group, and decreased by 14.17% than that of Sphingomonas sp. Z392 group. In conclusion, Sphingomonas sp. Z392 might reduce the release of NH3 by reducing the flux of purine and arginine metabolisms, while enhancing ammonia assimilation to form nitrite. In this context, ncd2 might be one of the key genes to reduce ammonia.

Development of stimuli-responsive cellulose textile finished with natural extract for detection of ammonia.

Development of stimuli-responsive cellulose textile finished with natural extract for detection of ammonia.

Short-term associations between ambient ammonia concentrations and growing-finishing pig performance and health

Short-term associations between ambient ammonia concentrations and growing-finishing pig performance and health

Insertion site of congenital extrahepatic portosystemic shunts influences clinicopathological findings in dogs.

Determine the influence of insertion site of extrahepatic portosystemic shunts (EHPSS) on clinicopathological findings in dogs. A retrospective study was performed in dogs diagnosed with an EHPSS. Cases were eligible if EHPSS morphology was categorized as portoazygos (PA) shunts, portocaval (PC) shunts entering the prehepatic caudal vena cava at the level of the omental foramen, or portophrenic (PP) shunts. Furthermore, completed standardized questionnaires on clinical signs at diagnosis had to be available. Signalment, clinical scores, and findings on blood analyses and medical imaging were determined and statistically analyzed. Data of 104 dogs (15 PA, 70 PC, and 19 PP shunts) were included. Dogs with PC shunts were significantly younger than dogs with PA and PP shunts. Furthermore, dogs with PC shunts had a significantly lower body condition score and a significantly worse clinical score compared to dogs with PP shunts. Microcytosis and monocytosis were more pronounced in dogs with PC shunts compared to those with PP shunts. Finally, urea and creatinine concentrations were significantly lower and preprandial serum bile acids and fasted ammonia concentrations were significantly higher in dogs with PC shunts than in those with PP shunts. Dogs with PC shunts are more likely to be presented at an earlier age, with more severe clinical signs and more distinct abnormalities in blood parameters compared to dogs with PP shunts. In older dogs with less distinct clinical signs suspected of having an EHPSS, screening for a PP shunt, which is more difficult to diagnose with ultrasonography, is recommended.

Leveraging the gut microbiome to understand the risk factor of cognitive impairment in patients with liver cirrhosis.

The role of the gut-liver axis in liver cirrhosis is becoming increasingly recognized. We investigated the fecal microbiome in patients with liver cirrhosis and its potential function as a predictive biomarker of hepatic encephalopathy. Patients were divided into either a high plasma ammonia (HPA) group or a low plasma ammonia (LPA) group according to the upper limit of normal of plasma ammonia concentration. 16S rRNA sequencing of fecal samples was performed to study how the microbiota affects the clinical symptoms of liver cirrhosis. The Stroop test was used to assess the ability of the brain to inhibit habitual behaviors. Totally, 21 subjects were enrolled. Among the 18 patients with liver cirrhosis, 14 were male, the age range was 42-56 years, and the plasma ammonia level range was 20-125.9 μmol/l. The Stroop test showed more severe cognitive impairment in HPA than in LPA individuals. At the same time, there were significant differences in fecal microbiome characteristics between the two groups, characterized by a further increase in the abundance of the Proteobacteria phylum in the gut (especially aerobic Enterobacteriaceae ). Function predictions of Phylogenetic Investigation of Communities by Reconstruction of Unobserved States in the microbiome further explained the increase in the Enterobacteriaceae -dominated polyamine synthesis pathway in the gut microbiome of HPA groups. Cirrhotic patients with hyperammonemia have a specific fecal bacterial composition (characterized via expansion of Enterobacteriaceae ). The ability to bio-synthesize polyamines that Enterobacteriaceae possesses is likely to be a key factor in the elevation of plasma ammonia.