Nitrogen Consumption Research Articles

Growth and Instability of Fertilizer Consumption in Haryana, India

The present study was undertaken to assess the growth in fertilizer consumption and instability by using the fertilizer consumption data for the period 1990-91 to 2019-20 and analyses by the exponential growth model. The periods of the study were divided into four sub-periods viz. Period-1 (1990-91 to 1999-00), Period-II (2000-01 to 2009-10), Period-III (2010-11 to 2019-20), and Overall period (1990-91 to 2019-20) for the meaningful elucidation of results. NPK consumption in Haryana across four divisions, during period-I, period II, and period III was found positive except for phosphorus in period III. Among all the fertilizers, higher growth was noticed in potash which has the highest variability as compared to other fertilizer nutrients. The variability in consumption of different nutrients (N, P, and K) in Haryana has shown that during period-I, II, III and overall nitrogen consumption was more stable, while, potash consumption was highly unstable during all the periods.

Application of PLC-Based Spectrophotometric System Nitrogen Protection Device to Automated Direct Measurement of Target Substances in Zinc Hydrometallurgy

Due to the fast material reaction in zinc hydrometallurgy, the traditional national standard photometric method cannot capture the characteristic information of target substances in real time. Herein, a nitrogen protection device is built based on ultraviolet spectrophotometry, supplemented by a programmable logic controller (PLC), to form an automatic control system for the direct detection of target substances (SO42−, Pb2+ and S2−) in zinc hydrometallurgy. The baseline straightness comparison results show that the nitrogen atmosphere can effectively improve the stability of the instrument. Furthermore, the detection sensitivity of SO42−, Pb2+ and S2− under the nitrogen atmosphere is higher than that of the air atmosphere, manifesting in sensitivity increases of 16.23%, 18.05% and 17.91%, respectively. Additionally, devices based on PLC systems show advantages over manual control both in states feedback and information backtrack. Moreover, the regulation time and nitrogen consumption during the regulation process are reduced by 80% and 75%, respectively, which effectively reduces the test cost and improves the equipment utilization rate (from four cycles per day to six cycles per day). The device can meet the requirements of different target substances and different process conditions by changing the electronic control parts and air source, so it has great application potential in the automatic direct measurement of target substances in zinc hydrometallurgy.

Statistical Modeling for Forecasting Fertilizer Consumption in India

Fertilizers have contributed significantly to increased agricultural yields, particularly for cereal crops and they will still be an important part of the science-based farming that is needed to feed the world's growing population. Fertilizers replenish the soil nutrients lost by the harvested crops, promote the use of high-yielding cultivars and boost biomass in tropical soils that are deficient in nutrients. In this study, data on fertilizer consumption in India was gathered from Agricultural Statistics at a Glance from 1950-51 to 2020-21 and utilized to fit the ARIMA model and forecast future usage. Forecasting has been done using the Box-Jenkins ARIMA approach. The ARIMA model is the most popular and widely applied forecasting model for time series data. The data was calculated using autocorrelation and partial autocorrelation functions. R programming software was used to estimate model parameters. The performance of the fitted model was evaluated using various goodness of fit criteria, such as AIC, BIC and MAPE. Empirical results revealed that the ARIMA (1,2,1) model was best suited to forecasting India's future total fertilizer use. Similarly, the ARIMA model was fitted for nitrogen, phosphorus, and potassium consumption in India independently. Forecasts from 2021-22 to 2030-31 are calculated using the chosen model. By 2030-31, total fertilizer use is predicted to reach 32,058.55 thousand tonnes. Policymakers should preferably base their judgments on reliable forecasts in order to tighten policies and achieve outcomes. Predicting future events using an appropriate time series model will assist policymakers, marketing strategies in making decisions related to export/ import and developing appropriate fertilizer consumption strategies.

Comparative Study of Soft Computing and Metaheuristic Models in Developing Reduced Exhaust Emission Characteristics for Diesel Engine Fueled with Various Blends of Biodiesel and Metallic Nanoadditive Mixtures: An ANFIS-GA-HSA Approach.

Since the discovery of petrol-based products, a surge in energy-requiring equipment has been established across the world. Recent depletion of the existing crude oil resources has motivated researchers to opt for and analyze potential fuels that could potentially provide a cost-effective and sustainable solution. The current study selects a waste plant known as Eichhornia crassipes through which biodiesel is generated, and its blends are tested in diesel engines for feasibility. Different models using soft computing and metaheuristic techniques are employed for the accurate prediction of performance and exhaust characteristics. The blends are further mixed with nanoadditives, thereby exploring and comparing the changes in performance characteristics. The input attributes considered in the study comprise engine load, blend percentage, nanoparticle concentration, and injection pressure, while the outcomes are brake thermal efficiency, brake specific energy consumption, carbon monoxide, unburnt hydrocarbon, and oxides of nitrogen. Models were further ranked and chosen based on their set of attributes using the ranking technique. The ranking criteria for models were based on cost, accuracy, and skill requirement. The ANFIS harmony search algorithm (HSA) reported a lower error rate, while the ANFIS model reported the lowest cost. The optimal combination achieved was 20.80 kW, 2.48047, 150.501 ppm, 4.05025 ppm, and 0.018326% for brake thermal efficiency (BTE), brake specific energy consumption (BSEC), oxides of nitrogen (NOx), unburnt hydrocarbons (UBHC), and carbon monoxide (CO), respectively, thereby furnishing better results than the adaptive neuro-fuzzy interface system (ANFIS) and the ANFIS-genetic algorithm model. Henceforth, integrating the results of ANFIS with an optimization technique with the harmony search algorithm (HSA) yields accurate results but at a comparatively higher cost.

Combined Effect of Ultrasound Treatment and a Mix of Krebs Cycle Acids on the Metabolic Processes in Saccharomyces cerevisiae

This article describes the effect of organic acids and ultrasound on the physiological and biochemical properties of yeast, which was used to obtain biologically active peptides. The research featured brewer’s yeast S. cerevisiae W-34/70 cultivated in 11% beer wort. A mix of Krebs cycle acids served as an activator. It included succinic, malic, fumaric, citric, and oxaloacetic acids (1:1:1:1:1). The concentration of the Krebs cycle acids was 1 × 10−10 M/L at 1% to the suspension volume. The ultrasound treatment had an intensity of 10 W/m2 and lasted 3–10 min. The combined effect increased the fermentation activity of the yeast by 98%. The activity of individual biocatalysts of constructive and energy metabolism rose by 108–330%, while that of proteolysis enzymes increased by 15% in comparison with the samples exposed to individual factors. The stimulation increased the rate of amine nitrogen consumption by the yeast. The amount of accumulated amino acids was larger by 80% than in the control, and that of protein larger by 7%. The maximal content of the synthesized protein was reached 1–2 h earlier. The combination of chemical and physical factors intensified the biosynthesis of protein and its intermediates during yeast processing, thus facilitating the subsequent extraction of biologically valuable components.

Enhancing Grain Yield and Zinc Content in Bread Wheat Using Zinc and Nitrogen Application under Supplementary Irrigation Treatments

Wheat (Triticum aestivum L.) is one of the crops that has great importance in human and animal nutrition. Nutrient management can improve the nutritional value and grain yield in bread wheat. Therefore, this study was conducted to assessment the effect of Zinc (Zn) levels as well as the interactions with Nitrogen (N) and irrigation regimes on yield, yield components and Zn content in bread wheat grain. To this purpose, an experiment was performed in a split-split plot design with four replications, which supplementary irrigation (no irrigation, irrigation at stem elongation and irrigation at the stage of grain filling) as the main plot, Zn levels as split-plot (no spraying of Zn and Spraying Zn with a concentration of 5%) and nitrogen consumption levels (nitrogen-free, half the normal dosage and normal nitrogen consumption) as split-split factors. The results showed that the grain yield and yield components affected by the applied treatments. The highest grain yield (646 g/m2 ) and Zn concentration (32.69%) observed in spraying Zn at 5% concentration supplemented with irrigation at the grain filling stage with normal N application. Also, Zn content of grain was increased by Zn foliar application. Furthermore, the grain yield significantly correlated with Zn content, Harvest index (HI), seed filling rate (SFR), thousand seed weight (TKW) and seed number per spike (SNS) traits. The highest grain yield was obtained in supplementary irrigation in grain filling stage indicating importance of supplementary irrigation in this stage. In general, the results of this study showed that the grain yield and quality in bread wheat could be increased by supplementary factors.

Life Cycle Assessment of NPK Fertilizers in Rice Production in Northern Iran

Life cycle assessment is an appropriate method to study the environmental impacts of producing a crop product throughout its cycle in a production system. Therefore, this research was conducted with the aim of evaluating the life cycle of paddy rice production under the effects of NPK fertilizers in Mazandaran province in northern Iran during 2017-2018. The different doses of nitrogen (N), phosphorus (P) and potassium (K) fertilizers were N250P150K150; N200P100K100; N150P75K75; N100P50K50, and control (N0P0K0). The results displayed that an average amount of cumulative energy demand and cumulative exergy demand was 11549.78 and 13443.08 MJ, respectively, that with increase of NPK consumption, both indices showed increasing trend. The average ecological footprint was 1190.80 m 2 a which CO2 emissions had shown the highest effect on the ecological footprint. The average of the impact categories of abiotic depletion was equals 12.44 kg Sb eq, acidification (3.15 kg SO2 eq), eutrophiction (2.33 kg PO4 eq), malodorous air (7295733 m3 air), freshwater sediment ecotoxicity (75.79 kg 1,4 DB eq), marine sediment ecotoxicity (116.11 kg 1,4 DB eq) that all of which enhanced with increasing NPK consumption. The average global warming potential (GWP) 20a and GWP 500a were 399.20 and 382.97 kg CO2 eq, respectively. Two indicators of human toxicity and terrestrial ecotoxicity in the three periods of 20, 100 and 500 years shows increasing amounts equal 0.42% and 140.70% during 20a to 500a, respectively. All pollutants released into the air and the water demonstrated enhancing trend with increasing NPK amounts. The emission of nitrate into soil, metals into the soil, and chemical oxygen demand showed enhancing trend with increasing NPK levels. Therefore, enhancing the emission of pollutants by increasing nitrogen consumption can be due to increase of yield.

Ekmeklik buğdayda (Triticum aestivum L.) 15N izotopu kullanılarak çiçeklenme sonrası kuraklığın azot mobilizasyonu ve gelişimine etkileri

Water and nitrogen shortage are one of the main limiting factors of crop productivity such as wheat and cereals. Increased variation and changes in climate conditions are expected to dominate yield potential of wheat. Nitrogen isotope technique widely used in recent years provides useful information about mobilization and nitrogen use efficiency under environmental constraints. This study aimed to determine the effects of drought conditions applied during different growing periods on nitrogen uptake by using stable 15N isotope, yield and quality properties and stomatal conductivity of bread wheat. Environmental variation was obtained by designing 4 artificial practices (irrigated condition, rainfed condition, early drought (flowering-harvest) and late drought (grain filling-harvest) by rainout shelter with covering progress about drought in different growing periods. Number of grains per spike, 1000 grain weight, single spike yield, spike numbers per square meter, plant height, grain yield, biomass yield, stomatal conductance, protein, ash content and stem δ15N (‰), flag leaf δ15N (‰), grain δ15N (‰) values were determined. The drought period from the beginning of flowering till harvest of plants had adverse impact on grain yield and yield components. The results clearly indicated the practices that may cause drought stress in the generative period should be avoided. In addition, nitrogen use efficiency of bread wheat was disrupted with the decrease in the amount and efficiency of plant water use during drought periods. The results also revealed that contribution of nitrogen to crop yield decreased due to less consumption of nitrogen in plant metabolic activities during drought periods. Based on the results additional water supply decreased δ15N content in mature grains from 13420 ‰ to 9278 ‰. Nitrogen applied in stem elongation period had greater contribution to grain δ15N content (15269 ‰) compared to tillering growth stage (8975 ‰). Nitrogenous fertilizer application time suggested not to be delayed to improve nitrogen contribution in metabolic activities and to prevent postponing the tillering and stem elongation periods. The application of nitrogen improved mobilization and efficiency of nitrogen contribution to different plant parts during generative development stages of bread wheat.

Comparative Silk Transcriptomics Illuminates Distinctive Impact of Artificial Selection in Silkworm Modern Breeding.

Early domestication and the following improvement are two important processes in the cocoon silk evolution of silkworms. In contrast to early domestication, understanding of the improvement process is still fuzzy. By systematically comparing the larval silk gland transcriptomes of the wild, early domestic, and improved silkworms, we highlighted a novel landscape of transcriptome in the silk glands of improved ones. We first clarified that silk cocoon protein genes were up-regulated in modern breeding but not in early domestication. Furthermore, we found that differentially expressed genes (DEGs) between improved and early domestic silkworms (2711), as well as between improved and wild silkworms (2264), were obviously more than those between the early domestic and wild silkworms (158), with 1671 DEGs specific in the improved silkworm (IS-DEGs). Hierarchical clustering of all the DEGs consistently indicated that improved silkworms were significantly diverged from the early domestic and wild silkworms, suggesting that modern breeding might cause prompt and drastic dynamic changes of gene expression in the silk gland. We further paid attention to these 1671 IS-DEGs and were surprised to find that down-regulated genes were enriched in basic organonitrogen compound biosynthesis, RNA biosynthesis, and ribosome biogenesis processes, which are generally universally expressed, whereas those up-regulated genes were enriched in organonitrogen compound catabolic processes and functions involving in the dynamic regulation of protein post-translation of modification. We finally highlighted one candidate improvement gene among these up-regulated IS-DEGs, i.e., GDAP2, which may play roles in silk behavior and the overall robustness of the improved silkworm. The findings strongly suggest that modern breeding may facilitate effective control of the basic consumption of nitrogen and a stronger switch of nitrogen resources from other tissues to the silk glands, for an efficient supply for silk production, and implies the importance of brain behavior and robustness in silk yield improvement of modern breeding.

Targeted Nitrogen Management to Increase Cereal Production while Reducing Nitrogen Consumption in India

Nitrogen is the most essential nutrient in crop production but a substantial portion of applied N to the cropland is lost into the environment by means of volatilization, leaching, or emissions causing multiple adverse effects on terrestrial and aquatic systems and on human health. Consumption of Fertilizer-N in India, the second largest consumer of N fertilizer in the world, has increased steadily since 1960s and is expected to further increase in the future to produce more food to meet the projected food demand. However, inequality is the core of the problem with some regions applying more N fertilizer than required leading to negative environmental externalities and other regions applying far less N leading to lower yields and soil mining adding to the vicious cycle of food insecurity. A data-based approach to identify areas of N surplus/N deficit, the magnitude of nitrogen-use-efficiency (NUE) and N harvest gaps helps develop location-specific fertilizer management strategies. Here, we developed a global NUE atlas using various sources of data on N input and N output to show the priority areas of N management work to address the issues of over- and under-fertilization. Adopting this data-based approach and using examples from field and national level analyses, we suggest spatially tailored agronomic, economic, and policy strategies of N management to address food, fertilizer, and climate crisis in India.

Mathematical Modeling of Microalgal Growth during Anaerobic Digestion Effluent Bioremediation

The development of kinetic models aims at predicting the behavior of a system or analyzing the underlying mechanisms. This process is essential for understanding microalgal growth and optimizing culture conditions. In the case of microalgal cultivation in wastewater, the analysis becomes even more difficult as growth is often inhibited by several factors, such as nutrient limitation and light inadequacy. In this context, a mathematical model was developed to describe the microbial growth of the species Parachlorella kessleri in different reactor setups using either sterile or non-sterile anaerobic digestion effluent as a substrate. Three different mass balances were taken into consideration to describe biomass growth, phosphorus, and nitrogen consumption. Concerning biomass growth, the logistic model was applied to evaluate the inhibition in biomass formation due to lack of illumination. The maximum optical density under which these species could grow was quantified with an ODmax parameter, which was estimated at 4.07 AU/cm for the Erlenmeyer flask and 2.79 AU/cm for cylindrical photobioreactors. Regarding the nitrogen mass balance, two different terms concerning microalgal assimilation and ammonia stripping were implemented into the equation. The proposed model predicted biomass growth with high accuracy in model training (R2 = 0.90) and validation (R2 = 0.89).

The impact of short-term nitrogen starvation and replenishment on the nitrate metabolism of hydroponically grown spinach

Nitrate is used as a source of supplemental nitrogen for plants, but it can also contribute to nitrate accumulation in green vegetables, which is unhealthy for humans. This study involves short nitrogen starvation and nitrogen replenishment treatments to minimize the nitrate content in spinach (Spinacea oleracea L.) in order to maximize nitrogen consumption and reduce the nitrate content. For this purpose, five different nitrogen application levels (N0 = 0 mmol·L−1, N4 = 4 mmol·L−1, N8 = 8 mmol·L−1, N12 = 12 mmol·L−1, N16 = 16 mmol·L−1) were used in hydroponic culture, in order to screen out the appropriate nitrogen application level of spinach and carry out short-term nitrogen starvation and replenishment treatment, the nitrate and nitrite contents, nitrate reductase and nitrite reductase activities, nitrate reductase gene and nitrite reductase gene were measured every 5 days, and plant growth was monitored during the experiment together with morphological adaptations at the root level. Our results showed that N8 level of the five nitrogen levels was the most effective for the growth of hydroponic spinach. In contrast to the N8 level, spinach roots and leaves thrive healthier after subsequent short-term nitrogen starvation and replenishment (N8*), optimum nitrate metabolism and key enzymes, and decreased expression levels of NR and NiR genes after nitrogen deprivation, however, their expression increased after nitrogen replenishment. It indicated that NR and NiR genes can be used as a reference gene to reduce the nitrate content in vegetables. In conclusion, our results provided a practical approach for optimum nitrate fertilization that will not only improve spinach growth but also reduce nitrate content harmful for human intake.

The albino mechanism of a new theanine-rich tea cultivar 'Fuhuang 2'

To explore the mechanism of tea albino variation and high theanine formation, 'Fuyun 6' and a new theanine-rich tea cultivar 'Fuhuang 2' were as materials in this study, pigment content, metabolome and transcriptome of the two cultivars were analyzed by ultramicroelectron microscopy, widely targeted metabolomics, targeted metabolomics and transcriptomics. The results showed that five catechins, theobromine, caffeine, and 20 free amino acids, including theanine, glutamine, arginine, etc., were identified by targeted metabolomics. The amino acid content of 'Fuhuang 2' was significantly higher than that of 'Fuyun 6', and the theanine content was as high as 57.37 mg/g in 'Fuhuang 2'. The ultrastructure of leaves showed that the chloroplast cell structure of 'Fuhuang 2' was fuzzy, most of the grana lamellae were arranged in disorder, with large gaps, and the thylakoids were filiform. The determination of pigments showed that compared with 'Fuyun 6', the contents of chlorophyll A and B, carotenoids, flavonoids and other pigments of 'Fuhuang 2' decreased significantly, some important pigment-related-genes, such as chlorophyllase (CLH), 9-cis-epoxycarotenoid dioxygenase (NCED), flavonoid 3β-hydroxylase (F3H) and flavonoid 3', 5'-hydroxylase (F3'5'H) were significantly changed. Compared with 'Fuyun 6', 'Fuhuang 2' identified 138 significantly changed metabolites (SCMs) and 658 differentially expressed genes (DEGs). KEGG enrichment analysis showed that SCMs and DEGs were significantly enriched in amino acid biosynthesis, glutathione metabolism and TCA cycle. In general, the albino phenotype of 'Fuhuang 2' may be caused by a deficiency in photosynthetic proteins, chlorophyll metabolism genes and chlorophyll content. The accumulation of high theanine in 'Fuhuang 2' may be due to the low nitrogen consumption in yellowed leaves and the lack of carbon skeleton, amino and nitrogen resources are stored more effectively, resulting in the up regulation of metabolites and related gene expression in the amino acid synthesis pathway, theanine has become a significant accumulation of nitrogen-containing compounds in yellowed leaves.

Cotton fiber quality response to nitrogen depends on source-sink process, boll growth habit, and weather condition

Nitrogen can be critical in determining fiber yield and quality in cotton. Major purpose of this 3-years (2017, 2018, and 2019) study in Faizabad-Iran was to investigate the effect of nitrogen rates, excess on the need for maximum yield and its interaction with environment on fiber quality of bolls with different spatial and temporal distribution in cotton canopy. Field experiment was a split-plot design with four replications. Main plots included two nitrogen rates (LN: 100 and HN: 200 kg ha −1 ). Sub plots included four boll growth habits: U P E R –Upper bolls Early in the season; L O E R –Lower bolls Early in the season; U P L A –Upper bolls Late in the season; L O L A –Lower bolls Late in the season. Results showed that fiber yield and fiber quality in terms of fiber uniformity and fiber strength were not affected by experimental factors and their interactions. In all years, LN led to an optimum micronaire (3.5–4.9 µg inch −1 ) and medium length (25.4–28.6 mm) fibers in all growth habits. However, in 2017, HN combined with lower temperature (25.2 °C) during the boll development decreased LAI to boll number ratio (source restriction), delayed maturity, and shifted fiber yield to U P L A boll growth habit with fine (micronaire < 3.5 µg inch −1 ) and short length (< 25.4 mm) fibers. In 2018 and 2019 with 1.7 °C and 2.3 °C higher temperatures than 2017, HN increased LAI to boll number ratio (sink restriction), led accelerated maturity, and shifted fiber yield to U P E R and L O E R boll growth habits, while with the increase of nitrogen, the difference between growth habits in terms of fiber quality was observed only in 2018 that led to production of coarse (micronaire > 4.9 µg inch −1 ) and long length (> 28.6 mm) fibers in U P E R and L O E R growth habits. In 2019, the lowest lint yield distribution was observed in U P L A treatment, but the fiber quality parameters were similar in all growth habits. These results may conclude that nitrogen consumption, in excess of what required for maximum yield, affects the source-sink relationship and leads to the formation of bolls with different fiber quality within a canopy, and the response of these processes to nitrogen is affected by the environment. • High N did not improve fiber yield but decreased fiber quality. • Low N led to an optimum micronaire and medium-length fibers in all seasons. • In cold weather, high N led to fine and short fibers. • In warm weather, high N led to coarse and long length fibers. • High N changed lint yield contribution and its quality within canopy.

Multi-objective optimisation of engine characteristics of an RCCI diesel engine powered with Jatropha/1-pentanol blend: a Taguchi-fuzzy approach.

Researchers are examining the possibilities for alternative fuel research as a fossil fuel replacement in light of global energy insecurity and other urgent challenges like global warming, severe emissions, and growing industrialization. This research uses 1-pentanol as a low reactivity fuel and Jatropha biodiesel as a high reactivity fuel to explore the reactivity-controlled compression ignition engine characteristics. A water-cooled single-cylinder engine is used in an experiment with varied loads of 25%, 50%, and 75% at a constant speed of 2000rpm to examine the effects of operational parameters (i.e., (23 bTDC, 25 bTDC, and 27 bTDC) and (400bar, 500bar, and 600bar)). The fuzzy-based Taguchi approach predicts operational parameters, including fuel injection time, fuel injection pressure, and engine load. Utilizing this ideal model, one may increase brake thermal efficiency and braking power while minimizing unburned hydrocarbon and nitrogen oxide emissions. An L20 orthogonal array is used to analyze the effects of various variables on an engine running on B20/1-pentanol fuel, including engine load, fuel injection timing, and fuel injection pressure. Multiple models are generated and verified with the use of experimental findings. Compared to other operating parameters, for reducing oxides of nitrogen, hydrocarbons, and brake-specific energy consumption maximally, engine load of 75%, FIP of 400bar, and FIT of 23 bTDC are optimal based on the greatest MPCI value of 0.802.

Artificially constructing mixed bacteria system for bioaugmentation of nitrogen removal from saline wastewater at low temperature

To alleviate the inhibition effects of multi-stresses, a multi-bacterial bioaugmentation based on stimulating cell-to-cell interactions was applied to improve the stress potential of salt-tolerant aerobic granular sludge (AGS). Results showed that the consortium formed by a combination of salt-tolerant ammonia-nitrogen utilizing bacteria, salt-tolerant nitrite-nitrogen utilizing bacteria and salt-tolerant nitrate-nitrogen utilizing bacteria with a whole biomass ratio of 1:2:1 achieved maximum nitrogen consumption rate (μNH4+-N, μNO2--N and μNO3--N of 1.03, 0.57 and 11.62 mgN/L·h, respectively) at 35 gNaCl/L salinity and 15 °C. The flocculent consortium was aggregated by Aspergillus tubingensis mycelium pellet, which was made into a compound bacterial agent (CBA), and the comprehensive nitrogen consumption capability of CBA was further improved to 2.47–4.36-fold of single functional bacteria. 5% CBA (m/m) was introduced into the seafood processing wastewater in batches, in winter (12–16 °C), the removal efficiencies of NH4+-N and total nitrogen increased from 66.89% to 52.77% of native AGS system to 79.02% and 69.97% of nascent bioaugmentation system, respectively. The analysis of key enzyme activities demonstrated that the ammonia monooxygenase and nitrate reductase activities of the bioaugmentation system were increased to 2.73-folds and 1.94-folds those of the native system. Moreover, due to an increase of 6.18 mg/gVSS and 0.11 in the secreted exopolysaccharide and tightly-bound/total extracellular polymeric substances, respectively, bioaugmentation boosted the cell bioflocculation ability by 13.53%, which enhanced the robustness. This work provided a detailed and feasible technical proposal for enhancing the biological treatment performance of saline wastewater in cold regions.

Regime of nitrate nitrogen in chernozem during the cultivation of perennial grasses

The article presents the results of field experiments to study the dynamics of nitrate nitrogen in ordinary chernozem of the forest-steppe zone of the Krasnoyarsk Territory. The studies were carried out in 2017-2019 years in three-field grain-steam and 8 grain-grass crop rotations. Melilot and sainfoin were cultivated neat and under the cover of barley, incl. with seed treatment with Rizotorfin inoculant. Winter rye was sown in 2018 in a field of clean fallow in a grain-fallow crop rotation and after mowing the second cut of perennial grasses of the 2nd year of use in grain-grass crop rotations with a stubble seeder SZS-2.1 without preliminary tillage.It has been established that a high supply of nitrate nitrogen is characteristic of a steam field in a 0-20 cm layer of chernozem (19 mg/kg). The average supply of chernozem with nitrate nitrogen was formed by coverless crops of sweet clover and sainfoin and cover crops of sweet clover (9-10 mg/kg). In the crops of winter rye, according to various predecessors, an intensive consumption of mineral nitrogen by plants and a very low supply of soil with nitrate nitrogen (2-5 mg/kg) were noted. Grain-grass crop rotation with the cultivation of winter rye on binary and pure crops of sweet clover created the best conditions for the accumulation of nitrate nitrogen in the 0-40 cm layer of chernozem (6-8 mg/kg). The treatment of sweet clover and sainfoin seeds with the inoculant Rizotorfin determined a more intensive absorption of nitrate nitrogen from the soil and a low supply of nitrate nitrogen to the soil (4-6 mg/kg) in the crop rotation.

Estimating smart energy inputs packages using hybrid optimisation technique to mitigate environmental emissions of commercial fish farms

The current study uses a hybrid optimization technique (ANN and DEA) to estimate smart energy input packages to reduce the environmental emissions of fish farms. In 2021, enumerators visited polyculture fish farms in Pakistan and interviewed 216 farmers using a well-structured questionnaire. The results showed that energy consumption and production were 1,11,493 and 54,62,643 MJ per farm, respectively. ANN determined that the emitted 8,323.57 tons of CO2eq per farm could be reduced to 6,403.39 tons of CO2eq. At a given level of farm output, nitrogen, diesel fuel, and electricity consumption were reduced by 31 %, 22 %, and 13 %, respectively. Using the smart energy input packages, the fish farm achieved a 23 % drop in environmental emissions and a 20 % improvement in energy use efficiency. A sensitivity analysis revealed that the energy production of fish farming increased significantly by 2.22, 0.83, 0.26, 0.09 and 1.14 units, respectively, with an increase of one-unit labor, juvenile fish, diesel fuel, electricity and green grass. While the energy output of carp was significantly decreased by 0.43, 1.64, and 0.13 units, with a 1 unit increase in the energy from mixed powder, animal manure, and nitrogen, respectively. Therefore, this study recommends using targeted energy inputs and substituting diesel fuel with green energy to reduce the environmental emissions of fish farms.

Optimally Safe Tank Changeover Operation Using a Smooth Optimization Formulation.

Tank changeover is a routine process in industry for placing fuel tanks into or out of service. The operation must use inert gas to avoid the flammability zone. However, inert gas consumption should be minimized for economic reasons. This requires dynamic modeling and optimization of the process, as addressed in the present work. A new dynamic optimization problem for minimizing the inert gas consumption, while ensuring fire safety is proposed. As part of the problem constraints, the flammability zone is characterized by disjunctive constraints, which are then converted to a new simple, nonsmooth formula, removing the need for data regression. This together with the multi-mode flow equations in the model leads to a nonsmooth dynamic optimization problem. To enable reliable solution by gradient-based solvers, the problem is reformulated to a smooth one using sigmoid functions. Case studies of methane tank purging and filling operations demonstrate that the proposed approach is able to minimize the inert consumption by providing optimal trajectories of the tank inlet and outlet flow rates, while ensuring the operation remains outside the flammability zone. It is shown that the proposed dynamic optimization can yield significant economic benefits as it reduces the nitrogen consumption by about two-third in one of the examples solved.

Analysis on the evolution of nitrogen metabolism process and nitrogen supply hinterland pattern in Beijing's food system

As one of the main human activities affecting the global nitrogen cycle, food production and consumption caused a series of environmental issues with nitrogen, especially in densely populated cities. To comprehensively quantify these issues of cities, Beijing's food system was chosen as a case to build a refined 18-node nitrogen metabolic network model based on environmental and external support, its nitrogen budgets was innovatively accounted from the perspective of “bigger food system”, which contained the nitrogen flows both involved in and driving food metabolic processes. Then the key nodes were identified according to the principle of contributing more than 10% of total nitrogen inputs and emissions. Based on above, China Multi-Regional Input-Output table was used to further examine its nitrogen supply hinterlands and identify the key supply drivers from the sectoral perspective. The results show that the total nitrogen input of Beijing's food system increased by 32.6% but the nitrogen output increased by 64.8% between 1979 and 2019. The (1) Crop cultivation, (2) Animal husbandry, and (11) Urban residents are not only key nitrogen input nodes but also key nitrogen emission nodes. Besides, they drove the external nitrogen supply to Beijing's food system, thus should be the key managed objects. Hebei, Heilongjiang and Tianjin are the largest inland nitrogen supply hinterlands, while the foreign nitrogen supply increased by 15.8% from 2007 to 2019. Technical assistance, economic compensation and trade strategy adjustment are good ways to reduce hinterlands' nitrogen supply pressure. This study provides targeted management suggestions for the nitrogen sustainable of food system in cities and the nitrogen coordination among regions.