Ammonia Research Articles

Transforming waste to wealth: Impact of food waste‐derived soil amendments and synthetic nitrogen fertilizer on soil dynamics

AbstractApproximately one‐third of all food produced globally goes to waste, highlighting the need for sustainable waste management technologies like composting and anaerobic digestion. These technologies convert food waste into soil amendment products such as compost, liquid digestate (LD) and solid digestate (SD). However, these food waste‐derived soil amendments have relatively low nutrient contents compared with synthetic nitrogen (N) fertilizers such as urea, making their agricultural use challenging. Despite this, food waste‐derived soil amendments can enhance the physical and biological properties of soil, potentially creating synergistic effects when combined with synthetic N fertilizers. This study aimed to investigate effects of food waste‐derived amendments in soil applied at 50 kg ha−1 total N (compost, LD or SD) and synthetic N fertilizer [urea ammonium nitrate (UAN)] at 50 and 100 kg ha−1 total N. Over 56 days of soil incubation, greenhouse gases (CO2, N2O), soil chemistry (–N, –N, pH) and microbial biomass C (MBC) were measured. Results showed that LD + UAN 50 reduced cumulative N2O emissions by 23% compared with UAN 100, despite having the same total N and similar available N rate applied to soil. Replacing UAN with LD in farming practices can supply equivalent available N while lowering N2O emissions, offering a sustainable nutrient strategy. Moreover, applying food waste‐derived soil amendments can enhance N retention in soils, reducing the need for increased applications of synthetic N fertilizers to compensate for N deficits in farming. Food waste‐derived soil amendments can also act as a slower N release compared with UAN, reducing nitrogen run‐off. SD had the highest CO2 emissions, followed by LD and compost. SD + UAN 50 increased MBC levels because of higher carbon content and labile carbon, and available N because of the application of UAN. The major drawback of using SD compared with LD is that the process of evaporating LD to form SD causes high ammonia volatilization (ammonium in solution into ammonia gas) rates, reducing the available N in SD. Therefore, future studies should explore strategies to reduce ammonia volatilization of LD.

Evaluation of Ammonia Co-fuelling in Modern Four Stroke Engines

Ammonia is emerging as a promising alternative fuel for longer range decarbonised heavy transport, particularly in the marine sector due to highly favourable characteristics as an effective hydrogen carrier. This is despite generally unfavourable combustion and toxicity attributes, restricting end use to applications where robust health and safety protocols can be upheld. In the currently reported work, a spark ignited thermodynamic single cylinder research engine equipped with gasoline direct injection was upgraded to include gaseous ammonia port injection fuelling, with the aim of understanding maximum viable ammonia substitution ratios across the speed load operating map. The work was conducted under overall stoichiometric conditions with the spark timing re-optimised for maximum brake torque at all stable logged sites. The experiments included industry standard measurements of combustion, performance and engine-out emissions (including ammonia ‘slip’). With a geometric compression ratio of 12.4:1, it was possible to run the engine on pure ammonia at low engine speeds (1000–1800 rpm) at low to moderate engine loads in a fully warmed up state. When progressively dropping down below a threshold load limit, an increasing amount of gasoline co-firing was required to avoid engine misfire. Due to the favourable antiknock characteristics, pure ammonia operation was up to 5% more efficient than pure gasoline operation under stable operating regions. A maximum net indicated thermal efficiency (ITE) of 40% was achieved, with efficiency tending to increase with speed and load. For the co-fuelling of gasoline and ammonia in a pure ammonia attainable operating region, it was found that addition of gasoline improved the combustion, but these improvements were not sufficient to translate into improved thermal efficiency. Emissions of ammonia slip reduced with increased gasoline co-fuelling, albeit with increased NOx. However, the reduction in ammonia slip was nearly ten times the increase in NOx emissions. Comparing pure ammonia and pure gasoline operation, NOx reduced by ~60% when switching from pure gasoline to pure ammonia (as the latter is associated with longer and cooler combustion). Results were finally compared to those obtained a modern multicylinder Volvo ‘D8’ turbo-diesel engine modified for dual-fuel operation with ammonia port fuel injection (PFI), with the focus of the comparison being ammonia slip and NOx emissions.

Exploring the ammonia gas sensing properties of Gd doped CeO2 thin films deposited by spray pyrolysis method

The present study investigates the synthesis and characterization of Gd-doped CeO2 thin films using a simple nebulizer spray pyrolysis method for ammonia sensing application. The films were prepared with varying Gd concentrations from 1 to 5 wt%. The structural, morphological, and optical properties of the samples were analyzed to examine the effect of Gd doping on physical parameters, and the results show that the 4 wt% Gd doped sample exhibits the highest crystallite size, uniform particle size distribution, and a smaller optical band gap. Additionally, the presence of defects and oxygen vacancies in the host lattice is enhanced in this sample. The gas sensing properties of the 4 wt% Gd doped CeO2 exhibits a gas responsivity of 731 %, rise time of 10.4 s, and fall time of 9.2 s indicating that the fabricated thin film sensor was found to be ideal for room temperature gas sensing application. Overall, the study demonstrates that the 4 wt% Gd doped CeO2 thin film is a promising candidate for commercial gas sensor applications.

PENGEMBANGAN SISTEM TERINTEGRASI BERBASIS IOT (INTERNET OF THINGS) UNTUK MONITORING DAN KONTROL KUALITAS AIR PADA BUDIDAYA TAMBAK UDANG DARATAN

Water quality is very important for the sustainability of a shrimp farm, starting from the quantity and quality of shrimp harvested is very influential on the good quality of the pond water. The water quality in question is parameters such as water turbidity, a lot or clean of dirt in the pool, a pH value that suits your needs and ammonia content in the pond which is usually produced from shrimp manure. This research designed a water quality monitoring and control tool in shrimp ponds that is integrated automatically through an IoT-based system (Internet of Things) using the thingspeak application as a server and telegram bots as controls. Based on the results of tests that have been carried out, the tool has been able to determine the quality of water correctly. The error percentage was 0.01% for turbidity sensors, 0.05% for TDS sensors, 0.01% for pH sensors and 0.12% for ammonia gas sensors. Based on the results of direct data collection on shrimp ponds for 6 hours, the average value of water turbidity was 3.06 NTU, the lowest was 1.07 NTU and the highest was 5.99 NTU, for the average value of TDS content was 170.98 ppm, 150.00 ppm was the lowest and 204.12 ppm was the highest, for the average pH content was 7.80, the lowest was 7.50 and the highest was 8.74, and the average value of ammonia content was 0.004 ppm, 0.0007 ppm is the lowest and 0.0113 is the highest.

Efeito do gás amônia em cama aviária contaminada com Eimeria spp.

Avian coccidiosis is a common disease that affects poultry worldwide. The practices used to control this pathology in poultry are based mainly on the use of antimicrobials, which have generated increased resistance of Eimeria and other microorganisms. Research is therefore needed to devise new control models and strategies. The objective of our research was to evaluate the effect of different concentrations of ammonia gas on poultry litter artificially contaminated with unsporulated Eimeria spp. oocysts. Samples of sterilized poultry litter were placed in containers artificially contaminated with unsporulated Eimeria spp. oocysts. Samples were placed in plastic bags and ammonia gas was injected in concentrations of 0.2%, 0.4%, 0.8%, 1% and 1.2%. The tested dosages of ammonia gas inhibited the sporulation of oocysts in poultry litter by 100%. Our study indicates that ammonia gas is efficient in eliminating Eimeria spp. in poultry litter at concentrations equal to or higher than 0.2% after one hour of exposure. These results are promising because, through the use of the bedding disinfection method (shallow fermentation with ammonia injection) it will be possible to eliminate field oocysts, improving the result of coccidiosis vaccines.

Impact of Palladium Decoration on the Performance of Co-SmFeO<sub>3</sub> Based Gas Sensor

The enhanced ammonia gas sensing properties of palladium decorated Co-SFO are demonstrated here. Pristine SmFeO3 thick films fabricated by screen printing technique were surface modified with Co by dipping method (dipping time 3 min) and identified as Co-SFO thick films. They showed maximum sensitivity to 50 ppm ammonia at 200 °C. In order to further increase its sensitivity, Co-SFO thick film was dipped into Palladium nitrate solution for 1 min, 2 min and 3 min. Surface morphology of as-prepared thick films was studied by FE-SEM. Formation of PdO phase and its uniform distribution over Co-SFO surface was confirmed from EDAX spectra. Gas sensing results revel that the sensitivity of Pd decorated Co-SFO thick films towards 50 ppm ammonia was increased. Moreover, decrease in operating temperature was also observed. Pd decorated Co-SFO thick film with dipping time 3 min has maximum sensitivity at lower operating temperature. The improved sensitivity at low temperature was attributed to the sensitization of palladium which was discussed in details. Keywords: Co-SFO, Chemical sensitization, Noble metal, Gas Response, Reducing gas.

Development of superhydrophobic and superoleophilic CNT and BNNT coated copper meshes for oil/water separation

In this research, chemical vapor deposition (CVD) method was used to synthesize boron nitride nanotube (BNNT) powder. This method involves heating multi-walled carbon nanotube (MWCNT) and boric acid in the presence of ammonia gas up to 1000 °C. Then MWCNT and synthetic BNNT were coated on the copper mesh via dip-coating method separately to prepare nano-structured membranes for efficient oil/water separation. Various analyzes were performed to identify the synthetic BNNT properties (X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and prepared coated membranes (FESEM, atomic force microscopy (AFM), water contact angle (WCA), oil contact angle (OCA) and oil/water separation process). Water and oil contact angle analyzes showed the super-oleophilic properties of both membranes with the underwater OCA of about 128°. For the separation process, a dead-end filtration setup was used, and free oil water mixture and o/w emulsion were prepared. So, in the separation process water was retained and decalin passed through both prepared membranes. The flux of CNT coated membrane was about 458 L m2 h−1, while this amount was 1834 L m2 h−1 for BNNT coated membrane and 99% separation efficiency was achieved by both of them. This four-fold increase in flux is due to the fact that the inner diameter of boron nitride nanotubes synthesized is four times larger than the inner diameter of MWCNT.

Iron Oxide Direct Reduction and Iron Nitride Formation Using Ammonia: Review and Thermodynamic Analysis

The steel industry is one of the main contributors to global greenhouse gas emissions, responsible for about 7 to 9% of the world’s total output. The steel sector is under pressure to move toward net-zero emissions by reducing its consumption of coke as the main method of reducing iron-rich feed materials to iron. Due to its well-developed synthesis process, high supply chain, straightforward handling technologies, and highly developed long-standing infrastructure, ammonia has the potential to become a replacement for coke as a future iron ore reductant. This work reviews previous research on ammonia direct reduction of iron oxides and the possible formation of iron nitrides. A thermodynamic assessment using FactSage 8.2 thermochemical software was carried out examining the behavior of ammonia gas as the reductant upon heating, detailed evaluations of the stable phases present under different reaction conditions and using different feed materials, and the formation and stability of iron nitride phases. The results suggest that the reduction of hematite with ammonia occurs in two steps below 570 °C and three steps above 570 °C. The ratio of Fe2O3/NH3 was predicted to affect the reduction reactions by promoting a greater reduction degree and simultaneously lowering the initial temperature needed for reduction, while the excess gas concentration can suppress FeO formation. A predominance area diagram was developed showing the main areas of stable phases as a function of the partial pressure of NH3 and temperature. The formation of iron nitrides during the process was predicted and these were not expected to cause issues for the formation of iron due to their instability under the conditions studied. This analysis can be used to inform further experimental studies regarding ammonia reduction of iron oxide.Graphical

A new design of colorimetric films using bacterial cellulose nanocrystals derived from nata de coco for sensing volatile organic compounds

In this work, bacterial cellulose (BC) derived from Nata de Coco is a polysaccharide material, and it is further processed into bacterial cellulose nanocrystal (BCNC) via acid hydrolysis. Then BCNC is doped with transition metals to enhance its amine/hydrogen sulfide response. Therefore, the aim of this study is to investigate the use of transition metals as indicators to detect amine and hydrogen sulfide gas for efficiently monitoring food spoilage. BCNCs were treated with various concentrations of silver nitrate (AgNO3) and copper sulfate pentahydrate (CuSO4·5H2O). Then the dropwise addition of ascorbic acid was applied to reduce Ag+ and Cu2+ to Ag0 (silver nanoparticle) and Cu0 (copper nanoparticle), which refer to red brown and red wine colors, respectively. The results indicated that BCNC/Ag nanoparticles were spherical, while BCNC/Cu nanoparticles exhibited a rod-like structure. XRD results also presented the incorporation of Ag and Cu nanoparticles, as confirmed by both crystallography structures. Furthermore, UV–Vis spectra showed the adsorption bands at 422–430 nm and 626–629 nm, belonging to Ag and Cu nanoparticles. After H2S and ammonia gas exposure, BH/Ag and BH/Cu films turned black from brown and red. In conclusion, transition metal-doped BCNCs exhibit potential for innovative food spoilage gas sensors.

Improved ammonia gas sensing performance at room temperature of polypyrrole by polyoxometalate decoration

Here, we introduced polyoxometalate (POMs) into polypyrrole (PPy) gas sensitive material for the first time to restrain the electron-hole recombination process and enhance the gas sensing performances. At room temperature, the sensing response value of PPy/POMs composite nanoparticles to 100 ppm NH3 gas can be improved to 80.85 %, 2.99 times than that of pure PPy nanoparticles. PPy/3 % SiW12 sensor response-recovery time was 39 s/166 s. It had good linearity (R2 = 0.9958), the LOD of NH3 was 85 ppb. In 21 days, the sensor still maintained over 90 % of the initial ammonia response value. Selectivity, repeatability and other sensing parameters were systematically investigated. In addition, the mechanism of sensing performance enhancement was analyzed and discussed. The study proved that POMs can separate electrons and holes, finally improved gas sensing properties. This work provides a new idea for the design and construction of high sensitivity PPy-based gas sensor by introducting polyoxometalates.

An Ammonia Gas Sensor Based on Reduced Graphene Oxide Nanocomposite Hydrogels

AbstractA flexible gas sensor based on nanocomposite has been developed and characterized for detecting ammonia gas (NH3) in the atmosphere. This sensor utilizes nanocomposite hydrogels composed of Arabic gum (AG), acrylic acid (AAc), reduced graphene oxide (RGO), and silver nanoparticles (AgNPs). Various techniques, including FTIR (Fourier Transform Infrared Spectroscopy), AFM (Atomic Force Microscopy), XRD (X‐ray Diffraction), SEM (Scanning Electron Microscopy), XRF (X‐ray Fluorescence), TGA (Thermo‐gravimetric Analysis), DSC (Differential Scanning Calorimetry), were used to evaluate the sensor‘s properties. The nanocomposite hydrogels showed exceptional swelling ability (597 %), advantageous for accommodating gas molecules like NH3. The Polymerization and network formation percentages of 31 % and 56 %, respectively, suggest a robust hydrogel matrix structure. When tested for NH3 gas sensing at room temperature, the RGO/AgNPs/AGPAAc‐hydrogel exhibited high sensitivity and stability compared to other variants across gas concentrations ranging from 0 to 100 ppm. The improved performance of the physiochemical properties of the nanocomposite hydrogels might be attributed to the combined effect of AgNPs and RGO, which likely enhance sensitivity and stability. Selectivity tests conducted for three gases at room temperature revealed that the sensor response was highly selective to NH3 at a concentration of 50 ppm. Furthermore, the sensor demonstrated consistent performance over time. These findings suggest potential applications in environmental monitoring and industrial safety, with the possibility of contributing to advancements in gas sensing technology and addressing environmental and safety concerns.

Smart bilayer film: Quality monitoring for freshness of fish and minced pork delights

Global concern over food spoilage and the pressing need for efficient spoilage detection methods have far-reaching implications for the well-being of millions of people worldwide. So, the emergence of systems capable of providing early detection and visible evidence of food spoilage has gained recognition as an essential tool in the fight against food spoilage. A smart bilayer label (SBL) was developed, which exhibits distinctive qualities, encompassing robust antioxidant and antimicrobial characteristics, responsive color alteration triggered by minor pH fluctuations, and the capability to exhibit color changes upon exposure to acetic acid and ammonia gas. The SBL shows robustness regarding mechanical, thermal, and barrier properties, including water and oxygen resistance and overall hydrophilicity. The ability of SBL to detect the freshness of fresh fish and minced pork at 6 °C was determined. Over time, for both fish and pork, an increase in pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and total viable counts (TVC) were detected. Notably, SBL changed to green on days 8 and 10 for fish and minced pork, respectively, corresponding to pH ranges of 7, indicating spoilage. This study validates the SBL as an effective freshness indicator, with a color change discernible to the naked eye (ΔE > 12), and highlights its potential for monitoring the quality of protein-rich products. Strong positive correlations between pH, TVB-N, TVC, and storage time underscore their interdependence (P < 0.01). The SBL’s ΔE positively correlates with pH, TVB-N, and TVC, affirming its effectiveness as a visual freshness indicator. These insights advance our understanding of the evolution of meat quality and endorse the SBL's role in real-time monitoring and enhancing meat industry practices.

Implementation of various injection rate shapes in an ammonia/diesel dual-fuel engine with special emphasis on combustion and emissions characteristics

As the problem of global warming continues to intensify, carbon-free fuel ammonia is crucial for internal combustion engines, and a potential ammonia combustion route is dual-fuel mode. The impact of various injection rate shapes (trapezoid, wedge, slope, triangle, and rectangle) on engine combustion and emissions performance with 0 %, 20 %, and 40 % ammonia energy fractions were estimated. Under the identical ratio of the ammonia-doped schemes, the fuel injection gross mass and fuel injection duration are the same. The results indicate that the triangle injection rate shape can make the mixture of diesel and ammonia gas more uniform, leading to combustion in the combustion chamber closer to homogeneous combustion. When the injection shape is the triangle, the indicated mean effective pressure in the cylinder is the highest at 10.29 bar, which is 4.04 % higher than that of the pure diesel original injection shape. The triangle injection shape makes the ammonia-diesel dual fuel burn more concentrated, resulting in lower unburned ammonia loss and higher thermal efficiency. Under the 40 % ammonia energy fraction and triangle injection shape, the highest thermal efficiency reaches 40.57 %, 1.58 % higher than the pure diesel original injection shape. Additionally, it significantly reduces unburned ammonia emissions. The injection rate shapes have a minor impact on CO2 emissions. The rapid increase in-cylinder average temperature can substantially reduce N2O emissions, thereby lowering total greenhouse gas emissions. Among them, the total greenhouse gas emissions of 40 % ammonia energy fraction and triangle injection shape are the lowest, at 81619 ppm, which is 11.3 % lower than that of pure diesel original injection shape. On the contrary, it will increase NOx emissions. Conversely, the slopes exhibit the lowest NOx emissions at 220.8 ppm, representing an 88 % reduction compared to the pure diesel original injection shape.

Optimized global reaction mechanism for H2+NH3+N2 mixtures

Hydrogen and ammonia are playing an increasingly vital role in combustion technologies. Recently, some detailed reaction mechanisms (DRMs) can predict reliable laminar burning velocities (LBVs). Meanwhile, despite their broad applicability in practical combustion engineering, global reaction mechanisms (GRMs) suitable for ammonia and its mixtures with hydrogen or nitrogen have yet to be reported. This study aims to address this gap by investigating new GRMs. Five DRMs were used to calculate the LBVs, and their average values were employed as a reference. First, a single-step GRM was developed for hydrogen (H2 + 0.5O2 → H2O), and another single-step GRM was developed for ammonia (NH3 + 0.75O2 → 0.5N2 + 1.5H2O). However, their combined GRM did not provide reasonable predictions of LBVs for the H2+NH3 mixtures. Therefore, a 4-step GRM was developed consisting of the single-step hydrogen and three additional reactions, i.e., an endothermic ammonia decomposition (NH3 + 0.5O2 → NO + 3H), an exothermic NO reduction (NO + 2H → 0.5N2 + H2O), and an exothermic H recombination (H + H → H2). In conclusion, this 4-step GRM and its revisions could predict reasonable LBVs, flame temperatures, and primary product compositions for mixtures of hydrogen, ammonia, and cracked ammonia gas over a wide range of temperatures (300–600 K) and pressures (1–5 atm).

Features of a gas turbine combustion chamber in operation with gaseous ammonia

Achieving climate neutrality requires the use of alternative hydrogen carriers for energy purposes, with ammonia currently being considered. One potential application in the energy sector is gas turbine systems, for which combustion chambers need to be designed to efficiently combust ammonia within an airflow. This paper focuses on theoretical investigations of fuel combustion completeness and environmental cleanliness of a gas turbine combustion chamber with a thermal power output of 1.0 MW, operating on gaseous ammonia. A prospective scheme for organizing processes is proposed, based on pre-mixing ammonia with a portion of air in a special pre-chamber, the sequential introduction of the remaining air through a radial-axial swirler and a series of holes in the flame tube, ensuring stable fuel combustion. Two approaches were used for modeling combustion processes in such a combustion chamber: one based on chemical reactor theory and the other on three-dimensional hydrodynamic analysis. After conducting a detailed kinetic analysis, it was concluded that to maintain stable ammonia combustion while varying the air excess coefficient in the primary combustion zone from 1.4 to 2.0, the reactants need to remain in this zone for a duration exceeding 0.025 s. Based on these parameters, design schemes for two combustion chamber variants were developed, differing in combustion tube length and air distribution pattern, for operation with an ammonia flow rate of approximately 50 g/s and a pressure of 0.3 MPa, determining a gas outlet temperature of 1490 K. Three-dimensional calculations of aerodynamic flow structures, ammonia combustion, and formation of toxic components were conducted, revealing that the proposed process organization scheme ensures complete ammonia combustion and small nitrogen oxide emissions. These results have potential applications in the development of new gas turbine combustion chamber designs for decarbonized energy systems, including those integrated with solid oxide fuel cells.

Failure analysis of stainless steel metal hose used for welding

While using ammonia (NH3) gas at 10 bar/500℃, a stainless steel 304 metal hose used as a bellow expansion joint was fractured. It was observed that the fracture of the metal hose started near the weld between the hose and the flange, and progressed to approximately 1/4 of the circumference of the weld.No metallurgical defects were found in the weld where the crack occurred. However, the folded part of the metal hose is welded to the flange, which can cause cracks. In other words, when the metal hose is forcibly compressed or stretched in order to weld it to the flange, the stress concentration due to cold work, including residual stress cause the metal hose to become brittle or crack. It is determined that when a high strain cyclic load or torsional deformation is applied to a high-hardness metal component, the metal hose will reach fatigue failure in a short period of time.

Preparation and freshness detection of tofu based on In-doped CeO2 ammonia gas sensor

An ammonia (NH3) sensor with high sensitivity based on indium-doped cerium oxide (In/CeO2) was prepared by hydrothermal method, and its sensing mechanism was revealed by first-principles. Experimental results show that indium ion (In3+) doping can effectually increase the sensitivity of NH3 sensor based on CeO2, which is mainly attributed to the enhancement in the number of oxygen vacancies and oxygen free radicals on the surface of In/CeO2. In/CeO2 sensor for NH3 with a response value of 5412.93 at a concentration of 1000 ppm, which is 65 times that of CeO2 sensor. Moreover, the low detection limit (LOD) of In/CeO2 is 0.433 ppm and its response/recovery time to 5 ppm NH3 is 1.1 s/1.4 s. Furthermore, the density functional theory (DFT) calculation confirmed that NH3 has higher adsorption-induced charge transfer and adsorption energy on the surface of In/CeO2 than other gases. This makes it easier for In/CeO2 to adsorb NH3 molecules and release more conduction electrons, thus improving the performance of In/CeO2. In addition, In/CeO2 sensor can be effectively used to detect the freshness of tofu through the concentration of NH3 released by the tofu in different storage environments. This work is beneficial to the safety monitoring of high protein food.

Ammonia gas adsorption study using copper impregnated on mesoporous activated carbon from seaweed waste for indoor air purification

Ammonia (NH3), as a toxic gas, has negative impacts on human health even at low concentration, especially in narrowed spaces. In this study, activated carbon was synthesized from seaweed waste and copper was loaded on its surface (Cu/AC filter) to prepare a cost-effective NH3 adsorbent. Pyrolysis (carbonization) temperature can significantly affect the texture properties of activated carbon, and the best activated carbon sample with BET of 1114 m2/g was obtained through pyrolysis at 500 °C followed by KOH-activation at 750 °C. Different from other lignocellulosic biomass-based activated carbons (mainly microporous structure), the prepared algae-based activated carbons mainly have a mesoporous structure (pore size: 7.0–9.0 nm). Copper-impregnation significantly changed the surface chemistry of activated carbon, thereby greatly increasing the NH3 adsorption capacity (max: 128.6 mg/g). The adsorption performance was primarily determined by chemical adsorption (caused by copper impregnation and related inherent functional groups, including O–H, C–H, O–Si–O and SiO–H), followed by physical adsorption (caused by BET). Isotherm studies indicated that NH3 adsorption on Cu/AC filter followed the Langmuir model, whereas the adsorption kinetics followed the pseudo-second-order model. Furthermore, the adsorption mechanism was controlled by intraparticle diffusion model with initial adsorption behavior. This can be attributed to the mesoporous structures of activated carbon, consequently dramatically improving the diffusion efficiency. In addition, the Cu/AC filter showed good regeneration performance, as it can still remain above 90 % after 5 cycles. Finally, this study demonstrated that the seaweed waste is a good precursor for activation carbon and has great potential as excellent NH3 adsorbent for indoor air purification.

Environmental Effects of Using Ammonium Sulfate from Animal Manure Scrubbing Technology as Fertilizer

Processed manure products have the potential to substitute chemical fertilizers and the use of these products may increase resource efficiency in the food system and decrease emissions of ammonia (NH3) and greenhouse gasses (GHG). The yields of maize and grass, as well as emissions, have been determined from a processed manure product: liquid ammonium sulfate from nitrogen stripping animal manure (AS), in comparison to a regular mineral fertilizer, calcium ammonium nitrate (CAN), in a greenhouse experiment and a field demonstration using a sandy and a clay soil. NH3 emissions were determined by comparing AS with a dairy manure as a reference. The yield of both crops, their nitrogen nutrient use efficiency (NUE), and nitrous oxide (N2O) emissions were not significantly different, while NH3 emission was lower from AS compared to the dairy manure. As a side-effect, the sulfur (S) contents of the grass in the fields fertilized with AS were much higher than in the non-fertilized control. We conclude that AS, produced here with a pH &lt; 5.5, can be used as an alternative for CAN in Dutch dairy systems, or similar other system, if S leaching losses do not pose a problem for the environment. Meanwhile, care should be taken not to exceed S in feed above toxic levels for ruminants.

Assessment of Ammonia Emissions and Greenhouse Gases in Dairy Cattle Facilities: A Bibliometric Analysis.

A deeper understanding of gas emissions in milk production is crucial for promoting productive efficiency, sustainable resource use, and animal welfare. This paper aims to analyze ammonia and greenhouse gas emissions in dairy farming using bibliometric methods. A total of 187 English-language articles with experimental data from the Scopus and Web of Science databases (January 1987 to April 2024) were reviewed. Publications notably increased from 1997, with the highest number of papers published in 2022. Research mainly focuses on ammonia and methane emissions, including quantification, volatilization, and mitigation strategies. Other gases like carbon dioxide, nitrous oxide, and hydrogen sulfide were also studied. Key institutions include the University of California-Davis and Aarhus University. Bibliometric analysis revealed research evolution, identifying trends, gaps, and future research opportunities. This bibliometric analysis offers insights into emissions, air quality, sustainability, and animal welfare in dairy farming, highlighting areas for innovative mitigation strategies to enhance production sustainability. This research contributes to academia, enhancing agricultural practices, and informing environmental policies. It is possible to conclude that this research is a valuable tool for understanding the evolution of research on gas emissions in dairy cattle facilities, providing guidance for future studies and interventions to promote more sustainable production.