Ammonia Concentration Research Articles

Sludge from Arapaima Gigas Culture as an Alternative Culture Medium for Lipid Production in Nannochloropsis Sp

Objective: The objective of this work was to evaluate the use of sludge generated during the culture of Arapaima gigas as an alternative medium for Nannochloropsis sp. Theoretical Framework: Microalgae are photosynthetic micro-organisms with the ability to transform organic waste or effluents into valuable biomass. They are currently of great interest for their use in the food and pharmaceutical industry. Nannochloropsis sp. is a valuable microalga due to its excellent lipid profile. Method: The sludge used was collected from A. gigas culture ponds at the CITE Acuícola Pesquero Ahuashiyacu (Tarapoto-Peru). An aqueous extract of sludge (EAL) was obtained from the sample by a thermal procedure, which was dosed into the cultures at concentrations of 100, 150 and 200 mL/L. The experimental units followed the traditional batch culture arrangement under laboratory conditions. Guillard F/2 medium was used as control treatment. The characterisation of metals in the medium was performed by coupled plasma induction (ICP) and the determination of ammonium and nitrite by colorimetric tests. In addition, population density, productivity and total lipid content were estimated. Results and Discussion: Chemical analyses revealed high concentrations of calcium, sodium, magnesium, iron, potassium, phosphorus, ammonium and nitrite (655, 648, 283, 67, 32, 17, 1.5, and 10 ppm, respectively). Likewise, the best growth (3590.00 ± 91.24 x 104 cells/mL) and productivity (0.69 ± 0.01 g/L) was obtained with 200 mL/L of EAL, presenting significant statistical differences (p < 0.05) with respect to the other treatments. In contrast, the highest lipid production (29.67 ± 1.53 %) was observed in the control treatment, far exceeding the EAL cultures; however, no significant statistical difference was observed between EAL treatments. Research Implications: These results demonstrate the feasibility of using EAL as an alternative medium for the production of Nannochloropsis sp. with a positive environmental and economic impact on the production of A. gigas. Originality/Value: The use of sludge generated in fish culture, in particular A. Gigas, has not been reported previously. In this study, we demonstrate for the first time the feasibility of using this sludge in the culture of the microalga Nannochloropsis sp. which also has a high potential for use in fish larviculture.

Sustainable management of drinking water quality in the locality of Massouro, Chad

This study evaluates the quality of drinking groundwater in the city of Moussoro using geochemical, bacterial, and multivariate statistical methods. Access to safe drinking water is a major concern for the population in these regions, as the distribution of this resource is unequal across continents and is often affected by human activities, making it vulnerable. The analysis revealed two categories of water: potable and non-potable. The presence of pollutant indicators, such as Escherichia coli (E. coli) and total coliforms, was observed in most samples. This presence indicates water contamination and requiring monitoring and treatment before it is consumed by the population. Overall, most of the physicochemical parameters comply with the World Health Organisation guidelines for drinking water. However, the concentration of ammonium (NH4+) was high. Pollution elements such as ammonium (NH4+) and E. coli, indicate that human activities also contribute to water mineralisation. The study could ensure sustainable access to safe drinking water, thereby enhancing the overall quality of life in Moussoro.

Empirical Modal Decomposition Combined with Deep Learning for Photoacoustic Spectroscopy Detection of Mixture Gas Concentrations.

In photoacoustic spectroscopy based multicomponent gas analysis, the overlap of the absorption spectra among different gases can affect the measurement accuracy of gas concentrations. We report a multicomponent gas analysis method based on empirical modal decomposition (EMD), convolutional neural networks (CNN), and long short-term memory (LSTM) networks that can extract the exact concentrations of mixed gases from the overlapping wavelength-modulated spectroscopy with second harmonic (WMS-2f) detection. The WMS-2f signals of 25 different concentration combinations of acetylene-ammonia mixtures are detected using a single distributed feedback laser (DFB) at 1531.5 nm. The acetylene concentrations range from 2.5 to 7.5 ppm and the ammonia concentrations from 12.5 to 37.5 ppm. The data set is enhanced by cyclic shifting and adding Gaussian noise. The classification accuracy of the test set reaches 99.89% after tuning. The mean absolute errors of the five additional sets of data measured under different conditions are 0.092 ppm for acetylene and 1.902 ppm for ammonia, within the above concentration ranges.

Arrested development and increased incidence of sandprawn embryonic aberrations along an intertidal human recreation gradient.

Anthropogenic pressures are increasing in coastal ecosystems globally, yet identifying robust indicators of change and managing coastal resources can be complicated by phenotypic plasticity and differential life-history responses of key organisms. We illustrate this using biogeochemical and sandprawn (Kraussillichirus kraussi) response metrics along a human recreation gradient (trampling, sandprawn harvesting) in a South African lagoonal ecosystem. Benthic compaction, oxygen depletion and high porewater ammonia concentrations were associated with greatest recreation intensity. Sandprawn abundance was similar across the recreation gradient and body condition was counter-intuitively greater in areas with maximum recreation, but with higher frequencies of embryonic aberrations and arrested development. These findings suggest different vulnerabilities of life-history stages of sandprawns to recreation, with embryonic stages being highly susceptible. We suggest that embryonic aberrations and developmental changes in endobenthic crustaceans may be sensitive bioindicators of recreation-induced changes in sedimentary systems.

Assessing Crisis Management Tools for Sustainability of Industrial Safety

This study presents a comprehensive risk assessment of ammonia leaks, focusing on the quantitative modelling of hazardous area ranges, concentration dynamics, and thermal radiation effects under varying leakage scenarios using the ALOHA 5.4.7 software. The analysis involves two key scenarios: an ammonia gas leak and a pool fire, each modelled under distinct atmospheric conditions. For the gas leak scenario, ammonia concentrations were mapped across ERPG-defined hazard zones, ranging from low-level irritation zones (ERPG-1) to life-threatening exposure levels (ERPG-3), with maximum concentrations reaching 1500 ppm within a 110 m radius. The second scenario examined the impact of thermal radiation from a pool fire, identifying critical radiation zones where exposure to heat fluxes exceeding 10 kW.m−2 could cause fatal outcomes within 12 m. Despite ALOHA’s strengths in modelling acute exposure risks and providing valuable input for emergency response planning, the study identifies several limitations, particularly regarding the long-term environmental and health impacts of chemical releases and the effects of varying meteorological conditions. These findings suggest that integrating ALOHA with advanced real-time monitoring and AI-based prediction systems could significantly improve its capacity to manage dynamic, rapidly evolving industrial hazards.

Electrochemical Synthesis of Nitrite and Nitrate via Cathodic Oxygen Activation in Liquefied Ammonia.

The electrochemical oxidation of ammonia (NH3) enables decentralized small-scale synthesis of nitrate (NO3-) and nitrite (NO2-) under ambient conditions by directly utilizing renewable energy. Yet, their electrosynthesis has been restricted to aqueous media and low ammonia concentrations. For the first time, we demonstrate here a strategy enabling the direct electrooxidation of liquefied NH3 to NO3- and NO2- by using molecular oxygen, achieving combined Faraday efficiencies above 40%.

Simultaneous nitrification and denitrification framework for decentralized systems: Long-term study utilizing rope-type biofilm media under field conditions

This research introduces a novel approach to achieve simultaneous nitrification-denitrification (SND) under dynamic load conditions using a cost-effective rope-type biofilm technology. The approach represents a significant advancement in wastewater treatment, particularly beneficial for remote and decentralized communities. The biofilm-based SND process was developed using a pilot-scale flow-through reactor by implementing upstream carbon management with constant-timer-based aeration control versus dynamic-sensor-based aeration control strategies. The findings indicate that adding an upstream anaerobic pretreatment process to handle excess carbon plays a substantial role in achieving a sustainable SND process under a dynamic load environment using simple aeration on-off control. The most optimal nitrification performance of 0.32 g NH3-N/m2/d (89 % removal) was achieved under a 1-hour ON/30-minute OFF aeration. The process sustained an average bulk liquid DO of 5.16 mg/L and 3.80 mg/L during the aeration ON and OFF periods, respectively, facilitating a 0.13 g N/m2/d (41 %) total inorganic nitrogen (TIN) removal, notably, implementing advanced aeration strategies driven by DO, NH3, and NO3 sensors enhanced TIN removal efficiency to 72 %. The nitrification performance remained comparable (89 % removal), resulting in 3 and 10 mg N/L effluent ammonia and TIN concentration, respectively. Additionally, utilizing two multivariate approaches accounting for 82 % and 64 % of the variance, this study discerned patterns in monitored variables and performance. Additionally, the analysis underscored the difference of bulk liquid DO levels in the biofilm versus suspended systems inhibiting the SND process. Distinct bacterial communities were established in biofilms under aerobic, anaerobic, and SND conditions, with the SND reactor showing a hierarchy of functional group and enzymes, enriched sequentially from heterotrophs to denitrifiers, nitrifiers, and anammox bacteria. These innovations underline the potential of tailored control strategies to enhance a passive biofilm-based SND process efficiency under dynamic conditions, providing scalable solutions for diverse target water quality demands in remote communities and decentralized systems.

Stable nutrient removal from wastewater with fluctuating seawater content ensured by an adaptable aerobic granular sludge microbiome

Seawater intrusion in coastal regions can alter the wastewater composition, threatening the microbial communities in wastewater treatment processes. An aerobic granular sludge (AGS) system was challenged by fluctuations in wastewater salinity levels promoted by seawater intrusion events for 286 days, divided into two stages. During stage I, the seawater content in wastewater increased stepwise, and over stage II the seawater content in wastewater oscillated throughout the day. Most of the time, the AGS effectively removed COD during the anaerobic phase, regardless of the wastewater salt content. Ammonium removal was slightly unstable (ca. 75 ± 19 %) during stage I, with nitrite release in the effluent. Over stage II, the ammonium content in the wastewater was fully removed. The nitrite content in the effluent decreased, and nitrate became the main nitrogen form released. Phosphate removal was quite unstable at the beginning, improving over time with complete removal achieved during stage II (ca. 98.4 ± 1.1 %). Taxa involved in nitrogen and phosphorous removal were identified in the AGS microbiome at both stages but with superior abundance in the latter stage. A diverse core microbiome, mainly composed of extracellular polymeric substances-producing bacteria (Thauera, Flavobacterium, Paracoccus) and denitrifying bacteria (Thiotrix, Azoarcus, Aequorivita) was identified in stage II. The AGS system efficiently managed daily oscillating seawater levels in wastewater, corroborated by the effective removal performance that seemed to be sustained by an adaptable AGS microbiome.

Ammonia removal and nitrogen preferences evaluation of indigenous Malaysian microalga Halamphora sp. on white shrimp Penaeus vannamei wastewater

Ammonia is ubiquitous in aquaculture systems and its removal is important for maintaining water quality and the health of the cultured animals. Microalgae are effective at removing ammonia from water, but the effectiveness of different microalgae species may vary. In this study, indigenous Malaysian microalgae isolated from shrimp ponds were screened for their ability in removing ammonia from synthetic culture media. The most efficient microalga’s nitrogen preferences and its growth and nitrogen removal in the early and late stages of shrimp culture wastewater were explored. It was found that four microalgae species namely Halamphora sp. BpSpD2, Chaetoceros sp. BpSpD3, Chlorella sp. BpSpG3 and Desertifilum sp. BpSpC1 were able to eradicate ammonia after 14 days of cultivation. Further investigation showed that Halamphora sp. BpSpD2 was able to remove 100 % ammonia within 5 days of culture. The nitrogen preferences of Halamphora sp. BpSpD2 indicated a preference for ammonia over nitrate as evidenced by the higher growth and removal efficiency of the treatments. Nitrogen removal efficiency of over 70 % was observed in treating 4 to 12 mg L-1 of TAN and nitrate. When tested in shrimp-cultured wastewater, Halamphora sp. showed a higher growth and 100% ammonia removal efficiency in the late stage of shrimp-culture wastewater. It also effectively removed 59% to 80% of nitrogen throughout both the early and late stages of shrimp culture wastewater. The results suggested that the microalga Halamphora sp. BpSpD2 has a significant potential to treat the effluent of an aquaculture system containing high concentrations of ammonia and nitrate.

Improved Anaerobic Digestion of Food Waste under Ammonia stress by Side-Stream Hydrogen Domestication

High ammonia concentration inhibits archaea's activity, causing the accumulation of H2 and acetate, which suppresses methane production in anaerobic digestion (AD). The study aimed to enhance microbial hydrogen metabolism through a side-stream hydrogen domestication (SHD) strategy, which involves applying hydrogen stimulation to a portion of the sludge separately. SHD maintained a stable methane yield of 407.5 mL/g VS at a high total ammonia nitrogen (TAN) concentration of 3.1 g/L. In contrast, the control group gradually decreased and stopped methane production at a TAN concentration of 2.3 g/L. Further analysis using enzyme activity assays, flow cytometry, and metagenomics explored the mechanisms underlying ammonia tolerance of SHD-treated group. SHD reshaped the microbial community, enriching homoacetogens and Methanosaeta-dominated methanogenic archaea. Key metabolic pathways including homoacetogenesis, butyrate degradation, propionate degradation, and methane production were enhanced. The activity of related enzymes also increased. Gene abundance in energy-generating pathways, such as glycolysis, was enhanced, ensuring adequate ATP production. Additionally, the high gene abundance of ion transport systems contributed to regulating proton imbalance and supplementing intracellular K+. This study provides important insights and practical guidance for developing novel techniques in the field of anaerobic digestion.

Distribution of Air pollutant Concentration and Ammonium conversion rate in Livestock Areas: Focusing on Boryeong

Objectives:The association between the generation of fine particulate matter (PM2.5) and ammonia is well-established, highlighting the importance of managing ammonia as a primary means to reduce particulate matter. However, domestic research on ammonia emissions, particularly in livestock areas, which are major sources of ammonia, is insufficient. This study aims to contribute to pollutant management on a national scale by conducting air pollutant measurements and analyses in livestock areas. Methods:Real-time analysis and monitoring of air and weather conditions were carried out in Boryeong, Chungcheongnam-do, from 2021 to 2022. Statistical analysis was then employed to investigate the correlation between observed air pollutants (ammonia, nitrogen oxides, sulfur oxides, ozone and particle matters) and PM2.5. Results and Discussion:As a result of the analysis, the concentration of air pollutants in Boryeong showed a seasonal tendancy to decrease in summer and increase after that. Most substances such as NO2, SO2, and PM10 were observed within the standard values. In the case of ammonia, domestic air environment standards are not in place, but the annual average was found to be 61.5 ± 55.3 ppb, higher than in other research results. This discrepancy is attributed to the influence of nearby livestock houses. It was also observed that PM2.5 exceeded the annual standard value of 15 μg/m3 in spring (30.1 μg/m3), summer (18.3 μg/m3), autumn (25.3 μg/m3) and winter (31.7 μg/m3), respectively. During this period, ammonium (NH4+, 32.8%), nitrate (NO3-, 35.9%), and sulfate (SO42-, 19.7%) comprised the majority of particulate pollutants in PM2.5. The ammonia-ammonium conversion rate (NHR) was 0.08 annual average, and it was found that gas/ion phase changes were affected by seasonal weather conditions (temperature and relative humidity). As a result of analyzing the NHR according to the PM2.5 concentration, it was found that the higher the PM2.5 concentration, the higher the NHR. Furthermore, although the measurement area of this study exhibited high ammonia concentration, the NHR was low. This suggests that the contribution rate of ammonia to PM2.5 was relatively low compared to the other studies.Conclusion:As a result, there is a need for measures to reduce the high concentrations of ammonia in livestock areas. Simultaneously, considering the diverse mechanisms involved in particulate matter formation, it is suggested that management of pollutants such as nitrogen oxides, sulfur oxides including ammonia should be implemented.

Effects of Pichia manshurica yeast supplementation on ruminal fermentation, nutrient degradability, and greenhouse gas emissions in aflatoxin B1 contaminated diets

Yeast feed additives present a natural approach for mitigating ruminal greenhouse gases (GHG) in an environmentally sustainable manner. This study aimed to isolate yeast strains from ruminal fluids capable of reducing GHG from Aflatoxin (AFB1) contaminated diets. Two isolates of Pichia manchuria (FFNLYFC1 and FFNLYFC2) were isolated and identified from the ruminal contents of dairy Zaraibi goats. An in vitro gas production assay was conducted to evaluate the impact of the yeast supplementations on a basal diet contaminated with AFB1 or not. The treatments were control (-AFB1; basal diet without supplements), control with AFB1 contamination (+ AFB1; basal diet containing 20 ppb AFB1), and yeast-supplemented diets (basal diet supplemented with Saccharomyces cerevisiae, and three treatments of P. manchuria [FFNLYFC1, FFNLYFC2, and their mixture at 1:1 ratio (Mix)]. High biological components were detected in abundance of both FFNLYFC1, FFNLYFC2 filtrates (e.g., diisooctyl phthalate). The Mix and FFNLYFC2 of P. manchuria reduced (P < 0.05) methane by 23.5 and 20.8%, respectively, while only Mix inhibited carbon dioxide by 44% compared to the + AFB1 diet. All yeast diets improved (P < 0.05) ammonia concentration, total protozoal and Entodinium spp. counts compared to + AFB1 diet. The Mix exhibited higher (P < 0.05) values of ruminal degraded cellulose, total short-chain fatty acids, acetate and propionate compared to the individual isolates diets. The results suggest synergistic interactions among P. manshurica isolates, leading to enhanced ruminal fermentation and reduced GHG emissions while alleviating the adverse effects of AFB1. Therefore, we recommended the Mix of P. Manchuria as a novel feed additive to ruminant diets.

An improved representation of aerosol in the ECMWF IFS-COMPO 49R1 through the integration of EQSAM4Climv12 – a first attempt at simulating aerosol acidity

Abstract. The atmospheric composition forecasting system used to produce the Copernicus Atmosphere Monitoring Service (CAMS) forecasts of global aerosol and trace gas distributions, the Integrated Forecasting System (IFS-COMPO), undergoes periodic upgrades. In this study we describe the development of the future operational cycle 49R1 and focus on the implementation of the thermodynamical model EQSAM4Clim version 12, which represents gas–aerosol partitioning processes for the nitric acid–nitrate and ammonia–ammonium couples and computes diagnostic aerosol, cloud, and precipitation pH values at the global scale. This information on aerosol acidity influences the simulated tropospheric chemistry processes associated with aqueous-phase chemistry and wet deposition. The other updates of cycle 49R1 concern wet deposition, sea-salt aerosol emissions, dust optics, and size distribution used for the calculation of sulfate aerosol optics. The implementation of EQSAM4Clim significantly improves the partitioning of reactive nitrogen compounds, decreasing surface concentrations of both nitrate and ammonium in the particulate phase, which reduces PM2.5 biases for Europe, the US, and China, especially during summertime. For aerosol optical depth there is generally a decrease in the simulated wintertime biases and for some regions an increase in the summertime bias. Improvements in the simulated Ångström exponent are noted for almost all regions, resulting in generally good agreement with observations. The diagnostic aerosol and precipitation pH calculated by EQSAM4Clim have been compared to ground observations and published simulation results. For precipitation pH, the annual mean values show relatively good agreement with the regional observational datasets, while for aerosol pH the simulated values over continents are quite close to those simulated by ISORROPIA II. The use of aerosol acidity has a relatively smaller impact on the aqueous-phase production of sulfate compared to the changes in gas-to-particle partitioning induced by the use of EQSAM4Clim.

Nitrogen fertilisation method affects wheat silage ammonia-N and crude protein content

ABSTRACT This study aimed to evaluate the nitrogen fertilisation supply method on wheat silage fermentation parameters and nutritional value. Eighteen experimental plots were used in a randomised block design to assess the following treatments: (1) control (CON): crop without nitrogen fertilisation; (2) surface (SUR): 100 kg/ha N during the crop, applied in surface; (3) furrows (FUR): 100 kg/ha N during the crop, applied in furrows during the seeding. Whole plants were manually harvested at 5 cm height 83 days after the sowing. One experimental silo (PVC tubes) was produced for each agronomical plot and stored for 69 days. In general, N fertilisation did not affect silage pH and ammonia-N (NH3-N) content, but silos FUR had less NH3-N than those with SUR. Fertilisation increased the CP and DM content and reduced starch in the silage. FUR increased DM and reduced CP compared to SUR. Furthermore, N fertilisation increased non-protein nitrogen and decreased in vitro degradation of DM and OM. Fertilisation methods did not affect N fractions in silage or in vitro degradation. Therefore, N fertilisation, especially FUR, reduces NH3-N and CP and increases DM content of silage, but decreases in vitro DM and OM degradation.

Analysis of subtract quality along the Wiringtasi River, Barru Regency, Indonesia

This research aims to determine the quality of the substrate of the Wiringtasi River, Barru Regency, Indonesia. The research locations include location 1, namely the location around the rice field area; location 2, namely the location around the pond area and beach; and location 3, namely the location around the river estuary where many mangrove plants grow around it. Subtract samples were taken at the research location, then the samples were taken to the laboratory for analysis. The results of laboratory analysis are made in the form of pictures and tables, then analyzed using descriptive analysis. The results of the research show that in this study the substrate quality of the Wiringtasi River, Barru Regency, Indonesia, each had a pH value of the substrate in the range of 8.05-8.64, total nitrogen was in the range. Nitrogen was in the range of 0.049-0.121%. The organic material content of the substrate is in the range of 0.33-0.59. The ammonia (NH3) content of the substrate is in the range of 0.019–0.45 ppm. The nitrite content of the research location is in the range of 0.0025-0.0064 ppm. The substrate texture of location 1 is dusty clay, while locations 2 and 3 are sandy.

Characterising the Chemical Composition of Bushfire Smoke and Implications for Firefighter Exposure in Western Australia

This study evaluates bushfire smoke as a workplace hazard for firefighters by characterising its chemical composition and potential health risks in Western Australia. Portable Fourier Transform Infrared (FTIR) spectrometry was used to measure airborne chemical concentrations at prescribed burns across five regions, including peat (acid sulphate) fire events. Samples were collected during both flaming and smouldering phases, as well as in perceived “clear” air resting zones. Results indicated that carbon monoxide (CO) was the dominant gas, reaching concentrations of 205 ppm at the fire front, followed by nitrogen monoxide (26 ppm) and methane (19 ppm). Peat fires produced distinct profiles, with ammonia (21.5 ppm) and sulphur dioxide (9.5 ppm) concentrations higher than those observed in typical bushfires. Smouldering phases emitted higher chemical concentrations than flaming phases 75% of the time. Even clear air zones contained measurable chemicals, with CO levels averaging 18 ppm, suggesting that firefighters are not free from exposure during rest periods. These findings highlight the need for fit-for-purpose respiratory protective equipment (RPE) and improved rest protocols to minimise exposure. The study underscores the importance of comprehensive health monitoring programs for firefighters to mitigate long-term health risks.

Determination of the Impact of Extruded Soybean Press Cake on Rearing and Health Indices of Piglets

The study was conducted to evaluate the alternative to imported soybean meal—extruded soybean press cake—in feeding weaning pigs. The experiment was carried out with 20 35-day-old weaned pigs weighing about 8.8 kg, divided into 2 groups (10 pigs in each) differing in the main protein source: group I—control, solvent-extraction soybean meal, group II— extruded soybean press cake. The feed mixtures were iso-protein and iso-energetic. After 35 days of feeding, the pigs were slaughtered. The samples of blood, intestinal tissue and digesta, meat, and back fat were collected for analyses. Replacement of soybean meal with extruded soybean press cake in the weaners’ diet had no statistically significant effect on growth performance and feed utilization. Histomorphometry analysis of the intestines did not indicate any harmful changes. The soybean press cake did not affect the sum of volatile fatty acids in the large intestine, but the ammonia concentration was lower in the distal colon (p ≤ 0.05). It was found that the extruded soybean press cake in the feed significantly affected the fatty acid profile (p ≤ 0.05) of meat and back fat, increasing the amount of PUFAs; however, no negative impact on the durability of meat and back fat during storage was noted. In conclusion, the study confirmed the possibility of completely replacing solvent-extraction soybean meal with extruded soybean press cake in the feeding of weaned pigs.

Ferulic Acid and Clinoptilolite Affect In Vitro Rumen Fermentation Characteristics and Bacterial Abundance

This study evaluated the effects of clinoptilolite (CTL) and ferulic acid (FA) supplementation on in vitro ruminal fermentation characteristics, gas production, and bacterial abundance. Treatments were arranged in a 2 × 2 factorial design (FA: 0 or 300 ppm; CTL: 0 or 1%) with repeated measures over time (2, 4, 8, 12, 24, 36, 48, and 72 h). Throughout the incubation period, the CTL and FAZ treatments recorded the highest pH values (p ≤ 0.05), maintaining levels closest to neutrality after 72 h. After 48 and 72 h, FA and CTL decreased (p ≤ 0.05) the ammonia concentrations while increasing (p ≤ 0.05) acetate and propionate. The methane, butyrate, and iso-VFA concentrations were unaffected (p &gt; 0.05) by any treatment. FA increased the total gas production throughout the experimental period (p ≤ 0.05). Additionally, FA and CTL significantly reduced the relative abundance of Ruminococcus albus and Streptococcus bovis (p ≤ 0.05), while no significant effects were observed for Selenomonas ruminantium (p &gt; 0.05). These findings suggest that both additives can positively modify the rumen fermentation characteristics and microbial composition, which could significantly contribute to animal nutrition by providing a promising strategy for enhancing rumen fermentation.

Synthesis and Characterization of Self-Dispersion Monodisperse Silica-Based Functional Nanoparticles for Enhanced Oil Recovery (EOR) in Low-Permeability Reservoirs

A controllable particle size mono-dispersing nanofluid system has been developed to address the challenges of low porosity and low-permeability in low to ultra-low-permeability reservoirs. This system combines high dispersion stability with enhanced oil recovery performance, and its effectiveness in improving recovery rates in low-permeability reservoirs, where conventional chemical flooding is ineffective, has been well demonstrated. Using the in situ method to prepare monodispersed nano-silica particles, the effects of the water concentration, ammonia concentration, and silica precursor concentration on the morphology, particle size, and formation time of the silica spherical particles were analyzed. Building on this foundation, a partially hydrophobic modified nano-silica oil displacement fluid was synthesized in situ. The system’s dispersion stability, ability to reduce oil-water interfacial tension, and capacity to alter rock wettability were evaluated. Core physical models were used to evaluate the oil displacement efficiency and the permeability applicability limits of the self-dispersing nano-silica oil displacement system. The experiments confirmed that the particle size distribution of the self-dispersing nano-silica oil displacement system can be controlled within a range of 10 nm to 300 nm. The nanofluids exhibited excellent stability, effectively altering the rock wettability from oil-wet to water-wet and reducing the oil-water interfacial tension to approximately 10−1 mN/m. The nano-displacement system increased the recovery rate of the low permeability reservoirs by more than 17%. The in situ modification method used to prepare these self-dispersing nanoparticles provides valuable insights for synergistic enhancement of recovery when combined with other systems, such as surfactants and CO2. This approach also opens up new possibilities and drives further development in the field of nano-enhanced oil recovery chemistry.

Pengaruh Waktu Aerasi terhadap Peningkatan Efisiensi Penghilangan Amonia di Air Lindi pada Sistem Ammonia Stripper

Talang Gulo Final Disposal Site (FDS) has a Leachate Treatment Plant (LTP) equipped with denitrification and nitrification facilities which function to reduce the concentration of ammonia (NH3) in leachate according to predetermined environmental quality standards. Research samples were taken in the form of leachate using the grab sampling method in accordance with SNI 6989.59:2008. The results of the research showed that the aeration time for the ammonia stripper of 3 hours, 6 hours and 12 hours both gave the highest value for the ammonia stripper efficiency percentage variable. The highest ammonia removal efficiency is aeration time of 12 hours. However, if we look at the operating efficiency of the ammonia stripper, the removal of ammonia by using an aeration time of 12 hours does not provide a significant improvement when compared to a treatment with an aeration time of 6 hours. This means that the operating time is 6 hours faster, the 6 hour variation can provide an ammonia removal efficiency of more than 90%