Sulfur Nitrogen Compounds Research Articles

Characterization and discrimination of the taste and aroma of Tibetan Qingke baijiu using electronic tongue, electronic nose and gas chromatography–mass spectrometry

Consumers rely on flavor characteristics to distinguish different types of Qingke Baijiu (QKBJ). Clarifying QKBJ's traits enhances its recognition and long-term growth. Thus, this study analyzed eight QKBJ samples from different regions of Tibet (Lhasa, Sannan, Shigatse, and Qamdo) using GC–MS, electronic nose and electronic tongue. The radar charts of the electronic tongue and electronic nose revealed highly similar profiles for all eight samples. Fifteen common compounds were found in all samples, with the main alcohol compounds being 3-Methyl-1-butanol, 1-hexanol, isobutanol, 1-butanol, 1-nonanol, and phenylethyl alcohol, imparting fruity, floral, and herbal aromas. However, the Sannan samples had higher total alcohol content than total ester content, emphasizing bitterness. Lhasa1 exhibited the most prominent sweetness, Lhasa2 the most noticeable sourness, and Qamdo the most pronounced umami. Lhasa3 and Lhasa4 had total acid content second only to total ester content. Tyd had the highest alkanes, while Lhasa had most aldehydes among samples.

Research Progress of Antioxidant Additives for Lubricating Oils

Lubricating oils play an important role in friction-reducing and anti-wear, as well as enhancing mechanical efficiency. To improve the oxidation stability and service life of lubricating oils, the composition and structure of antioxidants should be strategically designed, and these parameters have significantly affected the performance of antioxidants in lubricating oils. Antioxidants are classified into two types based on the substrates they act on: peroxide decomposers and radical scavengers. In this review, the effects of peroxide decomposers (including sulfur compounds, phosphorus compounds, sulfur–phosphorus compounds, and sulfur–nitrogen compounds) and radical scavengers, such as hindered phenols and aromatic amines, have been discussed as additives in the antioxidant properties of lubricating oils. The results indicate that peroxide decomposers have excellent performances in lubricating oils, but high pollution of S and P is not conducive to their widespread use. On the contrary, radical scavengers also have superior antioxidant properties and no pollution, possessing the potential to replace traditional antioxidants. In addition, molecular structures with (multiple) synergistic antioxidant properties have been extensively designed and reported. This review serves as a reference for researchers to design and develop high-end new antioxidants.

One-step hydrothermal synthesis of sulfur quantum dots for detection of Hg2+ ions and latent fingerprints

High blue-emitting sulfur quantum dots (SQDs) with quantum yields of up to 58.7% were prepared using elemental sulfur using a facile ethylenediamine-assisted hydrothermal acceleration method at 60 °C for 7 h. In the presence of ethylenediamine, bulk sublimated sulfur powder can be broken down into fine particles of sulfur-nitrogen compounds and then oxidized to produce SQDs. HRTEM analysis of the morphology of SQDs showed that SQDs had a quasi-spherical shape with a size of 3.2 nm. In this process, under the influence of ethylenediamine, sublimated sulfur is rapidly converted from zero-valent sulfur to polysulfide with simple heating, greatly improving manufacturing efficiency. Synthesized fluorescent sulfur quantum dots (SQDs) were used in this study as fluorescent probes for quantitative detection of Hg2+. The SQD served as an effective Hg2+ detection probe with a detection limit of 2.7 μM through an efficient on-off switching mechanism in response to Hg2+. In addition, latent fingerprints were recognized using SQD powder, and fingerprints were detected on the surfaces of various media, such as paper, glass, and aluminum foil. The synthesized SQDs have a high potential for sensing applications of various luminescent materials.

Insights into the photo-reduction of nitrate in the presence of CaSO3: Performance and mechanism

S(IV)-based advanced reduction processes have been viewed as effective strategies to eliminate nitrate (NO3−) from water. In this work, CaSO3 was introduced as the slow-release source of S(IV), and the combination of UV and CaSO3 was applied for NO3− reduction. 30 mg N/L of NO3− could be removed in the UV/CaSO3 process after 60 min reaction; UV irradiation and hydrated electrons (eaq−) reduction were responsible for the NO3− removal. The generated nitrite (NO2−) could further be removed in this process (UV/CaSO3). The degradation of NO3− increased from 65.8% to 100% with elevating CaSO3 dosage from 0.2 to 2 g/L, and the accumulation of NO2− decreased accordingly. Almost 100% removal of NO3− was achieved with initial pH being 3–12 without NO2− accumulation after reaction. The effects of anions (Cl−, CO32−, and SO42−) on the NO3− degradation and NO2− accumulation in UV/CaSO3 were negligible. Nitrogen (N2) was demonstrated as the major gaseous product during the NO3− reduction, and nitrogen-sulfur compounds (not NO2− or NH4+) remained the final liquid reduction products of NO3−. This study revealed that UV/CaSO3 would be a promising approach to remove NO3− chemically and simultaneously control the NO2− accumulation.

Spectroscopic studies of complex compound of Zinc with ligand of thio-trithiazylchloride and tyrosine

Tetrasulphur tetranitride, S4N4 has been recognised as an extremely versatile reagent for the preparing of sulphur nitrogen compounds via the reaction of both organic as well as inorganic species. Reaction with transition metal species result in the formation of a number of complex compounds. Reaction of thio- trithiazylchloride with tyrosine amino acid gave the new ligand. The spectroscopic studies of the reaction product of this new ligand with zinc oxide are reported in this paper on the basis of IR, UV, NMR and X- ray spectra

Fundamental study of jet fuel oxidative deposit formation

To better understand the composition of quartz crystal microbalance (QCM) deposits, samples were collected and analyzed by pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). Several compound classes were identified as significant components of QCM deposits. A compound that was detected by Py-GC/MS could not be conclusively identified from the electron ionization fragmentation pattern. Indirect evidence inspired a guess for this compound’s structure as a pentamethyl substituted cyclohexylpyridine. This hypothesis was confirmed by de novo synthesis of the hypothesized compound. Using the compounds that were identified through the Py-GC/MS experiments, a spiking study was performed to investigate their effect on QCM deposit formation. Along with exploring the significant nitrogen compound classes, sulfur compounds and alkyl phenols were varied during the study which had an effect on oxidation rates and deposit formation.

Chemical Composition of the Essential Oil of Neem (Azadirachta indica A. Juss. ) Seeds Harvested in Senegal

Objective: To make better understanding of the neem seed composition (Azadirachta indica A. Juss.) particularly in Senegal by the extraction, the proportioning and the determination of the composition of its essential oil. Methods: The extraction of essential oil from neem seeds is carried out by hydro-distillation. The Gas Chromatography (GC) and Mass Spectrometry (MS) were used for analysis and identification of components. Findings: The yield of essential oil from dry neem seeds (95.7% dry matter) is 0.076%. The major compounds identified are 5,6-dihydro-2,4,6-triethyl- (4H) 1-3,5-dithiazine (39.1%), cis 1,2,4-Trithiolane, 3, 5-diethyl (7.9%), 1-H-indole 2,3-dione (7.9%), trans 1,2,4-Trithiolane, 3,5-diethyl (6.2%), and ethyl thioisobutyrate (4%). The classification of compounds reveals that the essential oil of neem seeds is composed of sulfur and nitrogen compounds (40.1%), sulfur compounds (25.3%), and nitrogen compounds (15.1%), sesquiterpenes (7.4%), Fatty Acid Esters (FAE) (1.5%) and hydrocarbons (0.4%). This composition reveals that neem essential oil is mainly composed of non-terpene compounds. Novelty: The method of analysis by GC-MS although being the most widely implemented in the quantification and identification of volatile compounds is not applied in the case of neem seeds of African origin. Keywords: Chemical Composition; Essential Oil; Neem; Azadirachta indica; Seeds

Functional Compound Changes during Postharvest Physiological Deterioration of Cassava Tuber

Reducing the economic value of the cassava tuber crop, thereby Postharvest Physiological Deterioration (PPD) is the major problem in cassava that renders the tuber unmarketable. After harvest of cassava tuber causing fluorescence in the storage parenchyma was observed, because changes in metabolic compound mainly responsible for the fluorescence. Its content peaks within 24 hours of injury and prior to the development of the visual symptoms of physiological deterioration. The present study of Fourier infrared transform spectroscopy (FTIR) was performed with CI 850, YTP 1, H740/92 and H226 cassava genotypes to identify the functional compound changes during Postharvest Physiological Deterioration. FTIR spectroscopy is a technique based on the determination of the interaction between infrared (IR) radiation and a sample. The present study revealed that the extracts of fresh cassava tuber and stored tubers of different cassava genotypes, has potential to produce bioactive functional compounds like hydrocarbons, oxygen compounds, nitrogen containing compounds, isocyanates, thiocyanide, cyanide, isothiocyanates, oxidized nitrogen functions, sulfur compounds, phosphorous and amides but their quantity was differently in cassava genotypes which correlate with reinforcement of tolerance to PPD under storage condition.

Facile synthesis of high-performance sulfur quantum dots via an effective ethylenediamine-assisted acceleration strategy for fluorescent sensing

The present quest for sulfur quantum dots (SQDs) has been to circumvent the inefficient and laborious process involved in previous synthesis strategies. Here, intensely blue-emitting SQDs with a quantum yield up to 14.22 % are prepared by an effective ethylenediamine-assisted acceleration strategy with sublimated sulfur to SQDs conversion on the order of 6 h. The forming of SQDs includes the cleavage of bulk sublimated sulfur powders into small particles of sulfur-nitrogen compounds in the presence of ethylenediamine, which are oxidized to SQDs. The critical finding of this work is that sublimated sulfur can be rapidly converted from zero-valent sulfur to polysulfide by simple heating in the effect of ethylenediamine that dramatically boosts preparation efficiency. Significantly, the combination of SQDs and MnO2 nanosheets achieve fluorescence/scattered light ratiometric sensing of ascorbic acid with a limit of detection of 11.31 nM. This work provides a facile and rapid method for the fabrication of SQDs that could even enable SQDs to be applied in more expansive fields than carbon QDs and silicon QDs in the future.

Unravelling microbial populations and volatile organic compounds of artisan fermented liver sausages manufactured in Central Italy

The aim of the present study was to obtain information on the occurrence of bacteria and eumycetes in ready-to-eat fermented liver sausages manufactured by 20 artisan producers located in the Marche Region (Italy). To this end, culture-dependent analyses and metataxonomic sequencing were carried out. Physico-chemical parameters and volatilome of the fermented liver sausages were also studied. Finally, the presence of hepatitis E virus (HEV) was also assessed via real-time-RT-(q)PCR assays. Active microbial populations mainly represented by lactic acid bacteria, enterococci, coagulase-negative cocci, and eumycetes were detected. Enterobacteriaceae, Pseudomonadaceae, and sulfite-reducing anaerobes were not detected in most of the samples. Latilactobacillus sakei dominated in all the analyzed samples, reaching abundances up to 80%. Staphylococcus xylosus and Staphylococcus equorum were also detected. Among minority bacterial taxa, Weissella spp., Leuconostoc spp., Macrococcus caseolyticus, Brochothrix thermosphacta, Staphylococcus succinus, Lactobacillus coryniformis, Lactiplantibacillus plantarum, Lactococcus garviae, Psychrobacter spp., and Carnobacterium viridans were detected. The mycobiota was mainly composed by Debaryomyces hansenii that was present in all samples at the highest frequency. Among minority fungal taxa, Aspergillus spp., Penicillium spp., Kurtzmaniella zeylanoides, Candida spp., Yamadazyma spp., Scopulariopsis spp., Yarrowia spp., and Starmerella spp. were detected. Interestingly, associations between some taxa and some physico-chemical parameters were also discovered. The absence of HEV in all the samples attested a high level of safety. Finally, most of the VOCs detected in the analyzed fermented liver sausages belonged to six classes as: terpenoids, aldehydes, ketones, alcohols, esters, and acids. Nitrogen compounds, sulfur compounds, phenols, hydrocarbons, lactones, furans, and aromatic hydrocarbons were also identified. Several significant relationships were observed between mycobiota and VOCs.

Effect of biochar addition on the improvement of the quality parameters of compost used for land reclamation.

The 5% addition of biochar in composting in rows contributes significantly to reducing volatile organic compound(VOC) emissions. When composting with the addition of biochar, the average temperature increased by 13 ± 6.7 °C during the whole period, and the thermophilic phase was extended by 11 days. The higher temperature supported a reduction in the time necessary for achieving the biological stability observed by the oxygen uptake rate by more than 10 days. For organic compounds formed by the degradation of easily degradable primary components (proteins), the addition of biochar significantly reduces the release of organic compounds with heterocyclically bound nitrogen (Norg-VOCs) and volatile sulfur compounds (VSCs). The end of the biodegradation process is indicated by a decrease in VOC concentrations below initial values in the input material. This state was achieved in the compost with added biochar after 47 days, while in compost without added biochar, it lasted 60 days.

Performance and mechanism of biochar-coupled BiVO4 photocatalyst on the degradation of sulfanilamide

The construction of a low-cost and efficient novel photocatalyst is extremely important for the treatment of refractory wastewater. In this work, biochar-coupled BiVO4 (CBi) photocatalysts are synthesized using a hydrothermal method. These photocatalysts are then characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transition electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet visible diffuse reflection spectroscopy (UV–Vis-DRS), and photoluminescence (PL). The photocatalytic performance was also evaluated using the degradation and mineralization of sulfaniamide (4-aminobenzene sulfonamide, SA) under visible light irradiation. The results indicated that the CBi photocatalysts showed larger surface areas, stronger absorption abilities, higher separation efficiencies of photogenerated electrons and holes, and powerful transfer abilities of photogenerated electrons than the photocatalyst without biochar (CBi-0%). The CBi photocatalyst with the 20 wt% biochar (CBi-20%) exhibited an optimal photodegradation ability for SA. The degradation rate of SA was approximately 97.0% after 7 h of visible light irradiation, and the removal rate of total organic carbon (TOC) was as high as 83.4%, indicating an excellent mineralization ability. In addition, the CBi-20% photocatalyst obtained the highest mineralization rate of organic nitrogen (92.7%) and organic sulfur compounds (75.8%). Furthermore, spectroscopic techniques revealed more information regarding the degradation of the benzene ring and fluorescent groups. The fluorescence intensity and UV254 of SA were reduced by 96.5%% and 90.0%, respectively, which provided specific evidence of the potential photodegradation mechanism.

Coupling electronic nose with GC–MS improves flavor recognition and grade differentiation of Zhenjiang aromatic vinegar

AbstractIn this study, the flavor volatile profiles of five grades of Zhenjiang aromatic vinegar (ZAV) were compared using a gas chromatography‐mass spectrometer (GC–MS) and electronic nose (E‐nose). A total of 55 volatile compounds were identified, with 14 volatile compounds, including furfural, acetic acid, tetramethylpyrazine, phenethyl acetate, and phenylethyl alcohol, being identified as the key volatile compounds causing significant differences between different grades of ZAV samples. Principal component analysis (PCA) analysis of E‐nose data revealed that the W5S, W1W, W2W, W1S, and W2S sensors with high signal intensity to all ZAV samples correctly categorized the five grades of ZAV samples. The correlation analysis results suggested that the response signal intensities of W5S, W1W, and W2W had significant positive correlations with the abundances of acetic acid, isobutyric acid, ethyl phenylacetate, 3‐hydroxy‐2‐butanone, 2,3‐butanedione, 2‐acetylfuran, etc., adding to the evidence that W5S, W1W, and W2W sensors were sensitive to nitrogen oxides, sulfur compounds, pyrazines, and aromatic components. Based on the findings, it is possible to conclude that E‐nose, in conjunction with chemometric pattern recognition methods, can be used to differentiate between different grades of ZAV based on volatile compounds.Practical ApplicationsDifferent grades of Zhenjiang aromatic vinegar (ZAV) were distinguished by physical and chemical detection of total acid, nonvolatile acid, amino acid nitrogen and other indicators. In order to simplify the detection work, this study was to establish a rapid and feasible method for achieving ZAV grades differentiation according to their flavor volatile compounds. PCA of E‐nose data showed that the five grades of ZAV samples were well classified by the W5S, W1W, W2W, W1S, and W2S sensors. The correlation analysis results suggested that the response signal intensities of W5S, W1W, and W2W had significant positive correlations with the abundances of acetic acid, isobutyric acid, ethyl phenylacetate, 3‐hydroxy‐2‐butanone, etc., which adds to the proof that W5S, W1W, and W2W sensors were sensitive to nitrogen oxides, sulfur compounds, pyrazines and aromatic components. Therefore, E‐nose can be used as a rapid and nondestructive testing tool for quality measurements of ZAV.

Changes in Phenols, Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation.

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.

Effect of operating conditions on HDS of CGO blended middle distillate

Abstract The utilization of heavier stream of petroleum hydrocarbon such as coker gas oil (CGO) via diluting with straight run gas oil (SRGO) (blended feed: SRGO and CGO; 30/70) in order to enhance the middle distillate pool of fuel (heating oil, diesel fuel, jet fuel, and kerosene). Usually, CGO fraction has a propensity to retain refractory sulfur, nitrogen and aromatics compounds. The former two elements are mainly associated with the aromatic sulfur and nitrogen compounds (i.e., refractory). Hence, a systematic study was conducted with the variation of hydrotreating operating conditions to convert sulfur, nitrogen, and aromatic compounds. The performance was carried out in a fixed bed bench-scale reactor unit, using a commercial CoMo/Al2O3 (catalyst X) catalyst after sulfidation. The CGO has a significantly higher amount of nitrogen, aromatic, and refractory sulfur compounds than that of SRGO, which makes this blend more challenging. Hence, the operating conditions have been investigated to remove sulfur and nitrogen compounds and improve the cetane index during the hydroprocessing. The variation in operating conditions is to achieve 450 ppmS in the hydrotreated product using CGO and SRGO blend as a feedstock. The conversion of sulfur and nitrogen compounds indicated that hydrodesulfurization (HDS) is selectively higher than hydrodenitrogenation (HDN) where hydrogenation played a crucial role in their selectivities at high conversion. The hydrogenation function also relates to the cetane index that decreases with increasing aromatic content. The degree of inhibition (HDS and cetane index) depends on the feed composition (nitrogen and aromatics) that consumes a large amount of hydrogen. Conclusively, beyond 90% of HDS conversion, most of the sulfur compounds are refractory, which requires a stronger hydrogenation function to remove steric-hindrance from the refractory molecule.

6π, 8π and 10π Six Membered Sulfur Nitrogen Compounds: A Comparative Study with Organic Analogues

AbstractBenzene has played an important role in the development of the ideas concerning ′aromaticity′, as much as that benzene and its derivatives are the best examples of aromatic compounds. Although the inorganic aromatic compounds have been found to obey Hückel 4n+2 π electron rule, they often possess a different number of πe as compared to their organic analogues. One such system is cyclic compounds of S3N3, where 10 π aromatic S3N3− and 8π S3N3+ are known, but interestingly, a 6π benzene‐analogue of the sulfur‐nitrogen compound is not reported. Hence as a case study, we have undertaken an extensive theoretical investigation of the electronic structure of 6π, 8π and 10π electrons cyclic S3N33+, S3N3+ and S3N3−, based on the Energy Decomposition Analysis (EDA). We have also compared the results with isoelectronic classical C6H6, C6H62− and C6H64−. Our results indicated that the π‐contribution increases and the σ‐contribution decreases, while the contribution from the orbital interaction energy remains nearly similar upon addition of π electrons to C6H6 and S3N33+. However, the major decrease in the interaction energy is caused by the drastic reduction of the electrostatic component in C6H64− and S3N33+, which can be correlated to the instability of these molecules. Thus, aromatic binary compounds of sulfur and nitrogen are commonly π‐electron rich, while their aromatic hydrocarbon analogues are π‐electron precise.

High Pressure Investigation of the S-N2 System up to the Megabar Range: Synthesis and Characterization of the SN2 Solid.

Sulfur and nitrogen represent one of the most studied inorganic binary systems at ambient pressure on account of their large wealth of metastable exotic ring-like compounds. Under high pressure conditions, however, their behavior is unknown. Here, sulfur and nitrogen were compressed in a diamond anvil cell up to about 120 GPa and laser-heated at regular pressure intervals in an attempt to stabilize novel sulfur-nitrogen compounds. Above 64 GPa, an orthorhombic (space group Pnnm) SN2 compound was synthesized and characterized by single-crystal and powder X-ray diffraction as well as Raman spectroscopy. It is shown to adopt a CaCl2-type structure-hence it is isostructural, isomassic, and isoelectronic to CaCl2-type SiO2-comprised of SN6 octahedra. Complementary theoretical calculations were performed to provide further insight into the physicochemical properties of SN2, notably its equation of state, the bonding type between its constitutive elements, and its electronic density of states. This new solid is shown to be metastable down to about 20 GPa, after which it spontaneously decomposes into S and N2. This investigation shows that despite the many metastable S-N compounds existing at ambient conditions, none of them are formed by pressure.

Comparison of NOx and Smoke Characteristics of Water-in-Oil Emulsion and Marine Diesel Oil in 400-kW Marine Generator Engine

Currently, the exhaust gas of a ship is regulated for nitrogen oxides and sulphur compounds; however, there is no IMO regulation on smoke under discussion. This study investigated the reduction of exhaust gas through ship emulsion fuel, which can simultaneously reduce nitrogen oxides and smoke in ship engines before smoke regulations are established. The combustion and exhaust characteristics were investigated according to the moisture content of emulsion fuel using a 400-kW generator engine. As the water content of the emulsion and the temperature of the combustion chamber increase, micro explosion increases and the combustion period decreases. The nitrogen oxide and smoke from the emulsion fuel used in this study decreased by 7% and 75%, respectively. The nitrogen oxides and soot reductions obtained by the use of emulsion fuel were boosted by micro-explosion of water contained in the fuel during combustion.

Discrimination of fresh-cut broccoli freshness by volatiles using electronic nose and gas chromatography-mass spectrometry

This work was aimed to monitor the freshness of fresh-cut broccoli during refrigerated storage using electronic nose (e-nose) and solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC–MS). Traditional quality indices such as mass loss, chlorophyll content, aerobic plate count, sensory evaluation, malondialdehyde content and membrane permeability were also measured and the result of canonical discriminant analysis (CDA) can distinguish between fresh (on 0∼3 d), medium fresh (on 6∼9 d), and spoiled samples (on 12∼15 d). A total of 43 volatiles (including hydrocarbons, alcohols, esters, ethers, aldehydes, ketones, sulfur compounds and sulfur nitrogen compounds) were detected in broccoli samples using GC–MS analysis. Significant accumulation of sulfur compounds like dimethyl disulfide was observed as storage time increased. Both principal components analysis (PCA), hierarchical cluster analysis (HCA) and CDA on e-nose data could discriminate freshness of fresh-cut broccoli. The result of e-nose analysis was in good agreement with that of GC–MS analysis. This study suggested that e-nose has potential for applying as a rapid technique to determine freshness of fresh-cut vegetables.

A two-step method for the integrated removal of HCl, SO2 and NO at low temperature using viscose-based activated carbon fibers modified by nitric acid

Activated carbon fibers (ACFs) have been widely used as cost-effective integrated processes for the removal of nitrogen oxides, sulfur oxides and hydrogen chloride (HCl), while the competitive adsorption behaviors and the detailed interaction mechanisms have not been comprehensively investigated. In the current work, the adsorption capacities with one-step process and two-step method were compared, and the effects of HNO3 modification and ambient O2 concentration were simultaneously studied. Furthermore, the relative ratios of surface nitrogen groups, sulfur and chlorine compounds, as well as the soluble species on the ACFs surface, were respectively characterized by X-ray photoelectron spectroscopy and ion chromatography techniques. The results indicated that HCl, SO2 and NO were not able to be effectively removed with only one reactor due to the strong competitive adsorption behaviors, while the adsorption capacities of HCl, SO2 and NO were significantly improved by 30%, 280%, 230% in the two-stage reactors with HNO3 modification. Further investigation indicated interactions between HCl, SO2 and NO in the two-stage reactors are very complicated. The primary reactor can remove HCl and facilitate the catalytic removal of SO2/NO in the secondary reactor since HCl can severely inhibit the adsorptions of SO2 and NO, yet HCl adsorption can be suppressed by SO2. Simultaneously, nitro/nitroso groups derived of HNO3 treatment and NO oxidation can promote the chemisorption of HCl.