Removal Of Ammonia Gas Research Articles

Enhanced and prolonged adsorption of ammonia gas by zeolites derived from coal fly ash.

In this study, zeolites were synthesized from coal fly ash (CFA) using NaOH (Na-X type) and KOH (chabazite-K type) and used for the adsorption of ammonia gas in a fixed-bed reactor. Magnetic separation was used to decrease the Fe impurity content from 6.84 to 2.37 wt.%, and to increase the Si and Al content in non-magnetic fly ash (NMFA). BET surface areas of the zeolites increased significantly to 425.28 m2/g with an increase in micropore volume (ca. 0.12 cm3/g). FTIR and NH3-TPD analyses revealed that the increased surface area provided more acidic sites for enhanced ammonia gas adsorption. In particular, the zeolite (i.e., ZNF-X) synthesized from NMFA and NaOH showed the highest ammonia gas adsorption capacity (64.9 mg/g), owing to its high BET surface area and micropore volume. Although the initial adsorption capacity of commercial 13X zeolite (74.5 mg/g) was higher than that of ZNF-X, a much higher recycling efficiency for ZNF-X (92.0%) was achieved than for 13X (31.5%) during the five recycling tests because of the lower ammonia desorption temperature of ZNF-X. The results provide new insights into the synthesis of zeolites by upcycling of CFA and demonstrate the potential use of the generated materials for enhanced and prolonged removal of ammonia gas.

Ammonia gas treatment in low cost biological reactor

Ammonia gas contributes to a number of environmental and human health concerns. The use of chalk, a cheap alkalinity source may reduce costs for biological systems. This research studies a closed liquid flow reactor to treat ammonia gas using chalk as biomass media and alkalinity source with high value calcium nitrate fertilizer production.The proposed reactor showed complete ammonia gas removal at high rate (500 mg N/L/day) and with low cost; where chalk dissolution and ammonia gas absorption contributed to alkalinity in the water for nitrification. High calcium ion concentration (up to 10,000 mg Ca2+ as CaCO3/L) showed only minor effects on ammonia absorption and nitrification rate.

Characterization and Application of Mangosteen Peel Activated Carbon for Ammonia Gas Removal

Mangosteen peel can be used as an activated carbon precursor because of its high lignin content and hardness. In this study, mangosteen peel activated carbon (MP-AC) was prepared by a physical activation method using CO2 at 850°C. The Brunauer-Emmett-Teller (BET) analysis was used to assess the optimal activation time to identify the largest surface area. The properties of MP-AC were characterized by the SEM-EDS and FTIR analyses. The results showed that MP-AC obtained from the 120-minute activation time had the largest BET specific surface area of 588.41 m2/g and was selected as an adsorbent in the dynamic adsorption of ammonia gas. The values of moisture content, ash content, and iodine number of MP-AC were 6.07%, 9.8%, and 1153.69 mg/g, respectively. Breakthrough curve indicated that with lower inlet concentration and higher adsorbent mass, longer breakthrough time is reached. Equilibrium data was best fitted to the Langmuir isotherm, while the pseudo-first order kinetic model favorably described the adsorption kinetics. The results revealed a potential to utilize MP-AC as an adsorbent for ammonia gas removal with average NH3 adsorption capacity of 0.41 mg/g.

The Effect of Acidic Water Composition on Removal Efficiency of Air Ammonia in a Spray Tower

Introduction: One of the major factors that affect the employees' health and productivity in industries is the air quality of work environments. One of these pollutants is ammonia gas, which is very important from an economic and environmental points of view. Therefore, this study aimed to investigate the effect of using acidic water compound on the removal efficiency of air ammonia in a spray tower.
 Materials and Methods: In this study, airflow was provided by variable ventilation and water pressure through a class electropump. The rate of ammonia removal from the air stream was investigated by a spray tower with changes in water pressure, inlet gas density, and number of nozzles. For this purpose, at different inlet densities, different liquid pressures and different nozzles with water washing liquid with 0.01 mM sulfuric acid were used as the washing liquid.
 Results: Increased number of nozzles from one to three had a significant effect on ammonia removal (P-Value = 0.021). Increase of the inlet ammonia gas density from 24.1 to 68 parts per million significantly reduced the efficiency (P-Value = 0.058). Increase of the spray pressure from 9 bar to 12 bar also significantly increased the removal of ammonia gas from the spray tower outlet (P-Value = 0.052).
 Conclusion: Increased number of nozzles, increased spray pressure, and decreased density of the ammonia gas inlet gas will increase removal efficiency.

Long-term ammonia gas biofiltration through simultaneous nitrification, anammox and denitrification process with limited N2O emission and negligible leachate production

Ammonia is toxic and malodorous gas, which is emitted from agricultural and industrial sources. Most of known ammonia gas treatment methods share the disadvantages of expensive cost, by-product pollution and high energy consumption. In this study, an ammonia gas biotreatment method was developed, through simultaneous nitrification, anammox and denitrification process (SNAD) in a biofilter, which was expected to reduce operation cost, secondary pollution and energy consumption. Ammonia gas was converted to di-nitrogen gas (97.2–99.5%) and nitrous oxide (0.5–1.8%), with the highest ammonia loading rate of 0.173 gNH3/gVSS·d. Removed ammonia was taken up by both nitrification (70.6%) and anammox (29.4%) process. Anammox and denitrification process contributed to about 60% and 40% of di-nitrogen gas production in SNAD system, respectively. N2O emission might be caused by nitrification as well as denitrification processes, but not by anammox process in the reactor. TN removal efficiency achieved up to 99.4%, which suggested negligible leachate production in SNAD system for ammonia gas filtration. Anammox activity was not inhibited after introducing oxygen, which was most likely related to activity of oxygen-consuming ammonia oxidation, nitrite oxidation and denitrification. As far as know, this study is the first evidence for ammonia gas biofiltration with anammox-related technology, which might be a highly efficient and cost effective solution for ammonia gas removal with less energy consumption (<30%), biomass production (∼10%), greenhouse gas emission (70–80%) and wastewater production (100%).

Use of microalgae for mitigating ammonia and CO2 emissions from animal production operations — Evaluation of gas removal efficiency and algal biomass composition

The emissions of ammonia and CO2 from animal housing operations are a major challenge for concentrated animal feeding operations (CAFOs). A microalgae culture process was developed as a bio-scrubber to remove these gases. The green algae Scenedesmus dimorphus was grown in a flat panel photobioreactor aerated with ammonia- and CO2-laden air, with ammonia mass loading being fixed at 42.4mg/L·day and CO2 mass loading rates ranging from 0.64 to 5.49g/L·day. Within the range of the CO2 mass loading rate investigated, the ammonia gas removal rate was kept constant (41–42mg/L·day) with a high removal efficiency (>95%) from the inlet gas. The majority (80–90%) of the ammonia was removed by algal cell assimilation, with a small portion (10–12%) being removed via liquid dissolution. The CO2 removal rate and removal efficiency, however, highly depended on the CO2 mass loading rate used. The highest CO2 removal rate (0.6g/L·day) was achieved at CO2 mass loading rate of 1.18g/L·day, but the highest CO2 removal efficiency (78%) was achieved at the 0.64g/L·day CO2 mass loading rate. The cell biomass obtained contained 7–8% lipid, 55–60% protein, and 21–28% of carbohydrates. The amino acid profiles of the algal biomass are close to the ideal protein profiles for typical animal feeds, with a high ratio of essential amino acids. Collectively, the study shows that microalgae culture is an effective method for mitigation of ammonia and CO2 emissions from CAFOs, with the potential for use as an animal feed additive.

Removal of Ammonia Gas via Conducting Polymer-Assisted Titania Under Visible-Light or UV Exposure

Removal of Ammonia Gas via Conducting Polymer-Assisted Titania Under Visible-Light or UV Exposure

A laboratory study of microalgae-based ammonia gas mitigation with potential application for improving air quality in animal production operations

Ammonia gas emission is a major concern in concentrated animal production operations. It not only reduces the manure value as fertilizer due to nitrogen loss, but also has considerable environmental consequences for both animals and ecosystem. In this work, a microalgae culture system was developed as an ammonia gas bioscrubber to reduce ammonia gas emission. The green algae Scenedesmus dimorphus was grown in a flat-panel photobioreactor aerated with ammonia-laden air. A continuous culture was performed at different operational conditions including dilution rate (D = 0.05, 0.1, 0.2, and 0.3 day−1), ammonia gas loading rate (9.4, 19.3, 28.9, 39.9, 55.6 mg/L-day), and medium pH (5, 6, 7, and 8). The alga culture at 0.1 day−1 dilution rate, 39.9 mg/L-day ammonia gas loading rate, and pH 7 resulted in the highest cell density and biomass productivity. In order to provide a wide spectrum evaluation of the algae-based ammonia mitigation system, four parameters were determined, including ammonia removal rate, overall ammonia gas removal efficiency, cellular ammonia consumption rate, and cell yield based on ammonia input. Depending on the operational conditions used, the maximum values of those four evaluative parameters were 50.92 ± 2.91 mg/L-day of ammonia removal rate, 94.90 ± 1.87% of ammonia removal efficiency, 0.0597 ± 0.0024 g NH3/g cell-day of cellular ammonia consumption rate, and 19.40 ± 2.52 g cell/g NH3 of cell yield based on ammonia. It was also found that the majority of nitrogen in the ammonia gas was assimilated by the algal cells. At D = 0.1 day−1, 39.9 mg/L-day of ammonia gas loading rate and pH 7, algal biomass assimilated 98.6% of nitrogen contained in the ammonia gas input, with less than 5% of inlet ammonia gas was exhausted after the algal treatment. Implications: This study demonstrated the effectiveness of using microalgae for mitigating ammonia gas emission from animal production operations. The results enabled us to better understand the mechanisms of ammonia assimilation by microalgae, the engineering design parameters for the process scale up, and the economic viability of the system. Eventually, it will lead to a novel, alternative method for mitigating ammonia gas emission from concentrated animal operations while producing biomass as high-quality feed ingredient.

암모니아 가스 제거용 개질 활성탄의 표면특성

This research assessed the surface properties of modified activated carbons with three different acids and five different metals for ammonia gas removal. Raw bituminous coal-based activated carbon ( mesh) had low adsorption capacity of 0.72 mg based on the analysis in the column adsorption experiment. Adsorption capacities of carbons modified with , , and increased up to 3.34, 21.00, and 35.21 mg , respectively. Those of carbons with Cu, Zn, Zr, Fe, and Sn were 9.63, 9.13, 7.09, 25.12 and 15.03 mg . Ammonia adsorption was enhanced by the presence of surface oxygen groups on carbon materials, which influenced pH of carbon surface. BET surface area of raw carbon was analyzed to be , but it decreased by carbon surface modification. Fe-impregnated carbon showed of surface area. These observations were mostly caused by chemical adsorption.

DEVELOPMENT AND TESTING OF AN AMMONIA REMOVAL UNIT FROM THE EXHAUST GAS OF A MANURE DRYING SYSTEM

The storage and handling of animal wastes is one of the main sources of ammonia gas emissions. Ammonia gas has a distinct, unpleasant odor and can become detrimental to the health of humans and animals at high concentrations. Ammonia emissions are of particular concern in manure drying systems, where large losses of nitrogen, in the form of ammonia can cause air quality concerns. The aim of this study was to develop an ammonia removal system for a poultry manure drying system. The thin layer drying of poultry manure in 1-3 cm thick layers resulted in effective sterilization; with the removal of 99.44-99.56% of total bacterial count, 88.51-93.705 of yeast and mold cells, 99.13-99.565 of E.coli cells, and complete removal of Salmonellae. The drying of poultry manure resulted in a large loss of nitrogen, through ammonia loss in the exhaust gasses. The use of a water scrubber resulted in a 75-99% removal of ammonia gas from the exhaust gases. The absorption of ammonia into the scrubber’s water resulted in an increase in pH, which subsequently fell as the drying process finished, and ammonia emission decreased. The heated air drying of poultry manure, with the use of an ammonia removal system proved effective in reducing the odor intensity and offensiveness of the poultry manure drying process, resulting in increased air quality. While producing a high value product.

Biofilter Treating Ammonia Gas Using Agricultural Residues Media

Problem statement: Agricultural residues such as manure and sugarcane bagasse are wastes from agro-industry which has low value and requires some sustainable waste management method. In this research, a mixture of manure fertilizer and sugarcane bagasse is used as a biofilter media for an ammonia gas removal application. The aim of this research is to study the ammonia gas removal efficiency of such media. Approach: The experiments were conducted in laboratory-scale biofilters. Two inlet ammonia gas concentrations were used which are 500 and 1,000 ppm. Three ratios of manure fertilizer and sugarcane bagasse were studied including 1:3, 1:5 and 1:7 by volume. All experiments were conducted for a period of 40 days. Two Empty Bed Retention Time (EBRT) of these experiments were used which is 39s and 78s. The moisture content of the biofilter media was maintained at 45-60% by adding water. Results: The maximum ammonia gas removal efficiency at 89.93% is observed from the following conditions: 500 ppm of the inlet ammonia gas concentration, the manure fertilizer and sugarcane bagasse mixture ratio of 1:5 and the EBRT of 78s. The important factors of the ammonia gas removal in biofiltration process are the inlet ammonia gas concentration and the EBRT. Conclusion: The experimental results showed that the mixture of manure fertilizer and sugarcane bagasse is an effective biofilter media for ammonia gas removal applications. However, the biofilter is more effective at low inlet ammonia gas concentration, while the ratio of manure fertilizer and sugarcane bagasse has no significant effect on the ammonia gas removal efficiency. Therefore, using both residues as biofilter media for ammonia gas removal application is an alternative sustainable way to such manage argo-industry waste.

Removal of ammonia and particulate matter using a modified turbulent wet scrubbing system

Conventional scrubbers are typically modified to serve the needs of modern industries that discharge effluents that cause synergetic, adverse effects on the environment. We designed and developed a modified turbulent wet scrubber (MTWS) to remove air pollutants as they emerge from a coal furnace. Experiments were conducted to estimate the pressure drop and the efficiencies of ammonia gas and particulate removal via the MTWS. The optimum water levels and gas flow rates for effective scrubbing of ammonia gas at different concentrations and particulate matter at different feed rates were estimated. For ammonia gas at a concentration of 45ppm, a gas flow rate of 3.5m3/s and a water level of 58cm in MTWS and position B (central position of the nozzle) in the water level of the nozzle yielded efficient ammonia gas removal for the given time. Similarly, for a fly ash feeding rate of 140mg/min, the same gas flow rate and water level in the MTWS yielded high efficiencies even for particles at the submicron level.

Ammonia Gas Removal from Gas Stream by Biofiltration using Agricultural Residue Biofilter Medias in Laboratory-scale Biofilter

Ammonia Gas Removal from Gas Stream by Biofiltration using Agricultural Residue Biofilter Medias in Laboratory-scale Biofilter

Ammonia removal from a waste air stream using a biotrickling filter packed with polyurethane foam through the SND process

This paper presents the results of a bench-scale biotrickling filter (BTF) on the removal of ammonia gas from a waste stream using a simultaneous nitrification/denitrification (SND) process. It was found that the developed BTF could completely remove 100 ppm ammonia from a waste stream, with an empty bed retention time of 60 s and 98.4% nitrogen removal through the SND process under the tested conditions. It was elucidated that both autotrophic and heterotrophic bacteria were involved in the nitrogen removal trough the SND process in the BTF. Additionally, the elimination capacity of total nitrogen by the BTF increased from 3.5 to 18.4 g N/m(3) h with an inlet load of 20.6 g N/m(3) h (73.6%). The findings of this study suggest that the BTF can be operated to attain complete ammonia removal through the SND process, thereby making the treatment of ammonia-laden gas streams both short and cost-effective.

Bacillus subtilis PNG-4의 단독 및 Lactobacillus acidophilus와의 혼합 사용이 산란계의 건물소화율, 혈액성상 및 계분의 악취 발생에 미치는 영향

Two experiments were conducted to investigate the effect of probiotics on the malodor removal. In experiment 1, dietary effects (several malodorous gas concentration of excreta, dry matter metabolizability, and blood profiles) were determined using laying hens. A total of 30 Hy-line brown layers, 68-wk of age, were randomly allocated into 5 groups with 3 replicates of 2 birds each. The treatments were probiotics free, 0.2% and 0.4 % addition of mixed probiotics ( Bacillus subtilis PNG-4 + Lactobacillus acidophilus LAS), and 0.2 and 0.4 % addition of single probiotics ( Bacillus subtilis PNG-4). In experiment 2, the effects of mixing of probiotics into the excreta on the malodorous gas removal was investigated. There were three treatments (probiotics free, Bacillus subtilis PNG-4 + Lactobacillus acidophilus LAS, and Bacillus subtilis PNG-4) with three replicates. The malodorous gas concentrations were detected at 0, 3, 7 and 14 day of incubation. In experiment 1, ammonia concentration was significantly decreased by feeding mixed probiotics at 14th day of incubation. However, amines, hydrogen sulfide, ethylmercapthan, and methylmercapthan were not significantly affected by mixed probiotics. Dry matter metabolizability was significantly increased by feeding probiotics, but no significant differences between single and mixed probiotics. There was no significant differences in blood profiles. In experiment 2, mixing of probiotics into the excreta did not affect the concentration of ammonia, amines, hydrogen sulfide, ethylmercapthan, and methylmercapthan. Therefore, these experiments suggested that Bacillus subtilis PNG-4 + Lactobacillus acidophilus LAS supplementations could improve ammonia gas removal, and dry matter metabolizability in layers. Also, decrease of ammonia concentration was higher in mixed probiotics group compare to the single probiotics group. On the other hand, mixing of probiotics into the excreta appeared not to be a useful method.

Study on the kinetics of NH&lt;SUB align=right&gt;3 removal from air by Nitrosomonas europaea

In this paper, an attempt has been made to examine the feasibility of wood charcoal as a biofilter medium. The microorganism Nitrosomonas europaea has been utilised to remove ammonia in a continuous reactor. A maximum specific growth rate of 0.0565 h−1 was obtained for N. europaea in anaerobic environment using nitrate as electron acceptor. The slope of the graph between the maximum concentration of biomass and the nitrate concentration gave the growth yield (yield coefficient) for bacteria. The growth yield of N. europaea using nitrate as electron acceptor was found to be 1.67 and 92.67% removal of ammonia gas was found within seven days by wood charcoal-based biofilter.

Diversity of the bacterial community in a bioreactor during ammonia gas removal

Polymerase chain reaction analysis in combination with denaturing gradient gel electrophoresis (DGGE) was used to determine changes in the composition of the bacterial community of a bioreactor during ammonia removal. A minimum of 13 bands were observed in the DGGE profile. Phylogenetic analysis revealed that phylum Proteobacteria was predominantly represented in the bacterial community of the bioreactor, followed by Firmicutes, Actinobacteria, and Flavobacteriaceae. However, the occurrence and predominance of specific bacterial species varied with the concentrations of NH 3 introduced into the bioreactor. The complexity of the bacterial species generally decreased with increasing inlet NH 3 concentration. Based on the characteristics of the identified species, there is a potential for nitrification, denitrification, nitrate reduction, nitrite reduction, and ammonia assimilation to occur simultaneously in the bioreactor. The strains identified in this study are potential candidate strains for the purification of waste gases containing high concentrations of NH 3.

Studies on tin oxide-intercalated polyaniline nanocomposite for ammonia gas sensing applications

Thin films of tin oxide-intercalated polyaniline nanocomposite have been deposited at room temperature, through solution route technique. The as-grown films were studied for some of the useful physico-chemical properties, making use of XRD, FTIR, SEM, etc. and optical methods. XRD studies showed peak broadening and the peak positions shift from standard values, indicating presence of tin oxide in nanoparticles form in the polyaniline (PANI) matrix. FTIR study shows presence of the Sn–O–Sn vibrational peak and characteristic vibrational peaks of PANI. Study of SEM micrograph revealed that the composite particles have irregular shape and size with micellar templates of PANI around them. AFM images show topographical features of the nanocomposite similar to SEM images but at higher resolution. Optical absorbance studies show shifting of the characteristics peaks for PANI, which may be due to presence of tin oxide in PANI matrix. On exposure to ammonia gas (100–500 ppm in air) at room temperature, it was found that the PANI film resistance increases, while that of the nanocomposite (PANI + SnO 2) film decreases from the respective unexposed value. These changes on removal of ammonia gas are reversible in nature, and the composite films showed good sensitivity with relatively faster response/recovery time.

NH 3 gas absorption and bio-oxidation in a single bioscrubber system

A combined ammonia gas absorption and nitrification was conducted in a single bioscrubber. The reactor was consisted of a bubble column (gas absorption) and a packed bed (nitrification) which contained poly-urethane foams with immobilized nitrifying activated sludge. The entering gas and scrubbing liquid were contacted countercurrently. The bubble column elimination capacity (EC) was 26.74 g NH 3/m 3 h at >99% ammonia gas removal and effluent gas concentration lower than 2 ppm v. Without ammonium supplement, EC can reach 35.66 g NH 3/m 3 h which is equivalently the highest tolerable ammonia loading rate of 700 g N/m 3 day (1650 mg N/L) at the packed bed. At this level, 593 g N/m 3-day ammonia removal rate was achieved via nitrification, dominated by ammonia oxidation. Partial recycling (R/Q = 0.5) of scrubbing solution reduced the secondary wastewater volume by producing 233% more concentrated nitrified products. Hydraulic retention time (HRT) of 24 h was found optimal for both processes (gas absorption and nitrification).

Removal of ammonia from contaminated air in a biotrickling filter – Denitrifying bioreactor combination system

The removal of gaseous ammonia in a system consisting of a biotrickling filter, a denitrification reactor and a polishing bioreactor for the trickling liquid was investigated. The system allowed sustained treatment of ammonia while preventing biological inhibition by accumulating nitrate and nitrite and avoiding generation of contaminated water. All bioreactors were packed with cattle bone composite ceramics, a porous support with a large interfacial area. Excellent removal of ammonia gas was obtained. The critical loading ranged from 60 to 120 g m −3 h −1 depending on the conditions, and loadings below 56 g m −3 h −1 resulted in essentially complete removal of ammonia. In addition, concentrations of ammonia, nitrite, nitrate and COD in the recycle liquid of the inlet and outlet of each reactor were measured to determine the fate of nitrogen in the reactor, close nitrogen balances and calculate nitrogen to COD ratios. Ammonia absorption and nitrification occurred in the biotrickling filter; nitrate and nitrite were biologically removed in the denitrification reactor and excess dissolved COD and ammonia were treated in the polishing bioreactor. Overall, ammonia gas was very successfully removed in the bioreactor system and steady state operation with respect to nitrogen species was achieved.