Investigation of the nitrogen removal performance and microbial community structure in a full-scale A/O1/H/O2 coking wastewater treatment system.

Biological treatment processes are an effective method for removing the nitrogen-containing contaminants that exist in coking wastewater. However, little is known about microbial composition and keystone taxa involved in biological nitrogen removal processes. In order to improve the removal efficiency of nitrogen-containing contaminants in anaerobic-aerobic-hydrolytic-aerobic (A/O1/H/O2) system, the microbial composition and interactions of keystone taxa should be clarified. The present work clarifies the removal performance of nitrogen-containing contaminants in the A/O1/H/O2 system, identifies the microbial community involved in various bioreactors, and reveals the keystone taxa within the microbial communities. Combined the processes of ammoniation, denitrification, and nitrification, total nitrogen decreased from 248 to 31 mg L-1 and achieved a removal efficiency of 87.5% in the full-scale A/O1/H/O2 system. High-throughput MiSeq sequencing revealed that Proteobacteria was the most abundant phylum in the A/O1/H/O2 system with relative abundances of 24%-50%. Thiobacillus dominated in bioreactors A and O1 with relative abundances of 2.90% and 4.44%, respectively, while Nitrospira was identified as the most dominant genus in bioreactors H and O2, accounting for 13.33% and 18.38%, respectively. The microbial community composition and co-occurrence network analysis showed that the keystone taxa belonged to Thiobacillus, Nitrospira, Bdellovibrio, Planctomyces, Desulfotomaculum, and Sphingobium, which are related to nitrogen degradation.

Molecular Characteristics of Catalytic Nitrogen Removal from Coal Tar Pitch over γ-Alumina-Supported NiMo and CoMo Catalysts.

The removal of nitrogen from coal tar pitch (CTP) through the hydrodenitrogenation (HDN) of CTP and its molecular behavior were evaluated in the presence of NiMo/γ-alumina and CoMo/γ-alumina catalysts. Fourier transform ion cyclotron resonance mass spectrometry with atmospheric pressure photoionization was used to analyze the complicated chemical classes and species of CTP and the treated products at the molecular level. Nitrogen species were qualitatively analyzed before and after hydrotreatment. A single-stage hydrotreatment with an HDN catalyst resulted in a high sulfur removal performance (85.6-94.7%) but a low nitrogen removal performance (26.8-29.2%). Based on relative abundance analyses of nitrogen and binary nitrogen species, CcHh-NnSs was the most challenging species to remove during HDN treatment. Furthermore, prior hydrodesulfurization was combined with HDN treatment, and the dual hydrotreatments yielded a significantly improved nitrogen removal performance (46.4-48.7%).

Microbial community composition and function prediction involved in the hydrolytic bioreactor of coking wastewater treatment process.

The hydrolytic acidification process has a strong ability to conduct denitrogenation and increase the biological oxygen demand/chemical oxygen demand ratio in O/H/O coking wastewater treatment system. More than 80% of the total nitrogen (TN) was removed in the hydrolytic bioreactor, and the hydrolytic acidification process contributed to the provision of carbon sources for the subsequent nitrification process. The structure and diversity of microbial communities were elaborated using high-throughput MiSeq of the 16S rRNA genes. The results revealed that the operational taxonomic units (OTUs) belonged to phyla Bacteroidetes, Betaproteobacteria, and Alphaproteobacteria were the dominant taxa involved in the denitrogenation and degradation of refractory contaminants in the hydrolytic bioreactor, with relative abundances of 22.94 ± 3.72, 29.77 ± 2.47, and 18.23 ± 0.26%, respectively. The results of a redundancy analysis showed that the OTUs belonged to the genera Thiobacillus, Rhodoplanes, and Hylemonella in the hydrolytic bioreactor strongly positively correlated with the chemical oxygen demand, TN, and the removal of phenolics, respectively. The results of a microbial co-occurrence network analysis showed that the OTUs belonged to the phylum Bacteroidetes and the genus Rhodoplanes had a significant impact on the efficiency of removal of contaminants that contained nitrogen in the hydrolytic bioreactor. The potential function profiling results indicate the complementarity of nitrogen metabolism, methane metabolism, and sulfur metabolism sub-pathways that were considered to play a significant role in the process of denitrification. These results provide new insights into the further optimization of the performance of the hydrolytic bioreactor in coking wastewater treatment.

Multicomponent Reactions Involving Diazo Reagents: A 5-Year Update.

This review summarizes recent developments in multicomponent reactions of diazo compounds. The role of diazo reagent and the type of interaction between components was analyzed to structure the discussion. In contrast to previous reviews on related topics mostly focused on metal catalyzed transformations, a substantial amount of organocatalytic or catalyst-free methodologies is covered in this work.

Synthesis of Heterocycles through Denitrogenative Cyclization of Triazoles and Benzotriazoles.

During the past few decades, there has been considerable growth in the development of denitrogenative reactions of triazole skeletons to construct valuable cyclic compounds, particularly heterocycles. Despite the inherent difficulty of the ring-opening of triazole derivatives, many novel and efficient approaches have arisen in this area mainly with the use of transition metal (such as rhodium, palladium, silver, copper) catalysis, photolysis, or free radical mediated reactions. Generally, these procedures begin with the ring-opening of 1,2,3-triazoles or benzotriazoles followed by N2 extrusion and subsequent diverse transformations, which enable the rapid synthesis of various heterocycles in a single step. To avoid overlap with other related reviews, this minireview covers the recent advances in the denitrogenative cyclization of 1,2,3-triazoles since 2016 and the denitrogenative cyclization of benzotriazoles since 2012.

Time to Loss of Preoxygenation in Emergency Department Patients.

BACKGROUND: In patients requiring emergency rapid sequence intubation (RSI), 100% oxygen is often delivered for preoxygenation to replace alveolar nitrogen with oxygen. Sometimes, however, preoxygenation devices are prematurely removed from the patient prior to the onset of apnea, which can lead to rapid loss of preoxygenation. OBJECTIVE: We sought to determine the elapsed time, on average, between removing the oxygen source and the loss of preoxygenation among non-critically ill patients in the emergency department (ED). METHODS: We conducted a prospective, crossover study of non-critically ill patients in the ED. Each patient received two identical preoxygenation trials for 4 min using a non-rebreather mask with oxygen flow at flush rate and a nasal cannula with oxygen flow at 10 L/min. After each preoxygenation trial, patients underwent two trials in random order while continuing spontaneous breathing: 1) removal of both oxygen sources and 2) removal of non-rebreather mask with nasal cannula left in place. We defined loss of preoxygenation as an end-tidal oxygen (exhaled oxygen percentage; EtO2) value < 70%. We measured EtO2 breath by breath until loss of preoxygenation occurred. RESULTS: We enrolled 42 patients, median age was 43 years (interquartile range [IQR] 30 to 54 years) and 72% were male. Median time to loss of preoxygenation was 20 s (IQR 17-25 s, 4.5 breaths) when all oxygen devices were removed, and 39 s (IQR 21-56 s, 8 breaths) when the nasal cannula was left in place. CONCLUSIONS: In this population of non-critically ill ED patients, most had loss of preoxygenation after 5 breaths if all oxygen devices were removed, and after 8 breaths if a nasal cannula was left in place. These data suggest that during ED RSI, preoxygenation devices should be left in place until the patient is completely apneic.

Utilization of Deep Eutectic Solvents to Reduce the Release of Hazardous Gases to the Atmosphere: A Critical Review.

The release of certain gases to the atmosphere is controlled in many countries owing to their negative impact on the environment and human health. These gases include carbon dioxide (CO2), sulfur oxides (SOx), nitrogen oxides (NOx), hydrogen sulfide (H2S) and ammonia (NH3). Considering the major contribution of greenhouse gases to global warming and climate change, mitigation of these gases is one of the world's primary challenges. Nevertheless, the commercial processes used to capture these gases suffer from several drawbacks, including the use of volatile solvents, generation of hazardous byproducts, and high-energy demand. Research in green chemistry has resulted in the synthesis of potentially green solvents that are non-toxic, efficient, and environmentally friendly. Deep eutectic solvents (DESs) are novel solvents that upon wise choice of their constituents can be green and tunable with high biocompatibility, high degradability, and low cost. Consequently, the capture of toxic gases by DESs is promising and environmentally friendly and has attracted much attention during the last decade. Here, we review recent results on capture of these gases using different types of DESs. The effect of different parameters, such as chemical structure, molar ratio, temperature, and pressure, on capture efficiency is discussed.

Catalytic flash pyrolysis of Scenedesmus sp. post-extraction residue using low-cost HZSM-5 catalyst with the perspective to produce renewable aromatic hydrocarbons.

Recovering renewable chemicals from de-fatted microalgal residue derived from lipid extraction within the algal-derived biofuel sector is crucial, given the rising significance of microalgal-derived biodiesel as a potential substitute for petroleum-based liquid fuels. As a circular economy strategy, effective valorization of de-fatted biomass significantly improves the energetic and economic facets of establishing a sustainable algal-derived biofuel industry. In this scenario, this study investigates flash catalytic pyrolysis as a sustainable pathway for valorizing Scenedesmus sp. post-extraction residue (SPR), potentially yielding a bio-oil enriched with upgraded characteristics, especially renewable aromatic hydrocarbons. In the scope of this study, volatile products from catalytic and non-catalytic flash pyrolysis were characterized using a micro-furnace type temperature programmable pyrolyzer coupled with gas chromatographic separation and mass spectrometry detection (Py-GC/MS). Flash pyrolysis of SPR resulted in volatile products with elevated oxygen and nitrogen compounds with concentrations of 46.4% and 26.4%, respectively. In contrast, flash pyrolysis of lyophilized microalgal biomass resulted in lower concentrations of these compounds, with 40.9% oxygen and 17.3% nitrogen. Upgrading volatile pyrolysis products from SPR led to volatile products comprised of only hydrocarbons, while completely removing oxygen and nitrogen-containing compounds. This was achieved by utilizing a low-cost HZSM-5 catalyst within a catalytic bed at 500 °C. Catalytic experiments also indicate the potential conversion of SPR into a bio-oil rich in monocyclic aromatic hydrocarbons, primarily BETX, with toluene comprising over one-third of its composition, thus presenting a sustainable pathway for producing an aromatic hydrocarbon-rich bio-oil derived from SPR. Another significant finding was that 97.8% of the hydrocarbon fraction fell within the gasoline range (C5-C12), and 35.5% fell within the jet fuel range (C8-C16). Thus, flash catalytic pyrolysis of SPR exhibits significant promise for application in drop-in biofuel production, including green gasoline and bio-jet fuel, aligning with the principles of the circular economy, green chemistry, and bio-refinery.

Efficient destruction of basic organo-nitrogenous compounds in liquid hydrocarbon fuel using ascorbic acid/H2O2 system under ambient condition.

Due to the limitations of the conventional refinery methods, development of a new method such as oxidative denitrogenation (ODN) is highly desirable. This study described a novel ODN to remove organo-nitrogenous compounds (ONCs) in liquid fuel by ascorbic acid (AscH2) and H2O2 redox system under ambient conditions. Seven ONCs including pyridine, quinoline, acridine, 7,8-benzoquinoline, indole, N-methylpyrrolidone (NMP), and N,N-dimethylformamide (DMF) were chosen to assess the fuel-denitrified ability of the AscH2/H2O2 system. The results showed that the basic group of ONCs (pyridine, quinoline, and acridine) can be effectively removed (removal ratio > 95 %) while the removal efficiency of water-soluble compounds (7,8-benzoquinoline, NMP, and DMF) was moderate (61-68 %) under a mild temperature (30 °C) and atmospheric pressure. Free radical quenching and electron paramagnetic resonance experiments confirmed that hydroxyl and AscH2 radicals played a major role in the degradation of ONCs. The degraded products of quinoline were analyzed by gas chromatography-mass spectroscopy and ion chromatography. Based on the identified intermediate products, a putative reaction pathway majorly involving three steps of N-onium formation, transfer hydrogenation, and free radical oxidative ring-opening was suggested for the quinoline degradation. The presented approach can be performed at a normal temperature and pressure and will live up to expectations in the pre-denitrogenation and selective removal of basic ONCs in fuel oils.

Perspectives on strategies for improving ultra-deep desulfurization of liquid fuels through hydrotreatment: Catalyst improvement and feedstock pre-treatment.

Reliance on crude oil remains high while the transition to green and renewable sources of fuel is still slow. Developing and strengthening strategies for reducing sulfur emissions from crude oil is therefore imperative and makes it possible to sustainably meet stringent regulatory sulfur level legislations in end-user liquid fuels (mostly less than 10 ppm). The burden of achieving these ultra-low sulfur levels has been passed to fuel refiners who are battling to achieve ultra-deep desulfurization through conventional hydroprocessing technologies. Removal of refractory sulfur-containing compounds has been cited as the main challenge due to several limitations with the current hydroprocessing catalysts. The inhibitory effects of nitrogen-containing compounds (especially the basic ones) is one of the major concerns. Several advances have been made to develop better strategies for achieving ultra-deep desulfurization and these include: improving hydroprocessing infrastructure, improving hydroprocessing catalysts, having additional steps for removing refractory sulfur-containing compounds and improving the quality of feedstocks. Herein, we provide perspectives that emphasize the importance of further developing hydroprocessing catalysts and pre-treating feedstocks to remove nitrogen-containing compounds prior to hydroprocessing as promising strategies for sustainably achieving ultra-deep hydroprocessing.

Methylcellulose/tannic acid complex particles coated on alginate hydrogel scaffold via Pickering for removal of methylene blue from aqueous and quinoline from non-aqueous media.

Adsorbents reported for liquid phase decontamination under both aqueous and non-aqueous media are all dispersed phase sorbents that further require a tedious separation step post adsorption. Herein, a monolith, highly porous, and mechanically robust scaffold was synthesized for the adsorption of pollutants from both aqueous and non-aqueous media with facile separation and regeneration. Methylcellulose-tannic acid complex particles were prepared and systematically decorated on the surface of interpenetrating polymer network (IPN) scaffold via Pickering emulsion. Due to the surface coating of the particles, plausible amphiphilic adsorption of quinoline (QUI) and methylene blue (MB) was achieved from fuel and water, respectively. The hydroxyl (OH-) and carboxyl (COOH-) groups of tannic acid, alginate, and polyacrylic acid created hydrogen bonding, electrostatic interaction, acid-base interaction, and π-π stacking. Maximum adsorption capacity of 791.17 mg/g MB and 460.92 mg/g QUI was recorded with facile separation, excellent adsorbent regeneration, and reusability. Although both followed the pseudo-second-order adsorption kinetic model, a different mechanism was identified to govern the adsorption under aqueous and non-aqueous environment i.e. only the surface particles were active for QUI adsorption while the scaffold was also involved for MB adsorption.

A new LDH based sustained-release carbon source filter media to achieve advanced denitrogenation of low C/N wastewater at low temperature.

Advanced denitrogenation of wastewater is now facing major challenges brought by low C/N ratio and low temperature. The development of sustained-release materials with good and stable carbon release properties was an effective countermeasure. FeNi-Layered double-metal hydroxides (LDH)- sodium carboxymethyl cellulose (CMC) filter media and its potential use in heterotrophic and sulfur-based mixotrophic denitrification biological filter (DNBF), was firstly reported. It demonstrated stable structure and good carbon release performance with a mass transfer coefficient (K) of 4.40 mg·L-1·s-1. When the influent NO3--N of 50 mg/L with the C/N ratio of 3 at 10 °C, the maximum nitrogen loading rate of 0.22 kg·N/(m3·d) and effluent TN close to 5 mg/L (nitrogen removal of almost 90 %) could be achieved. The slowly released carbon source and the leached iron increased the abundance of denitrifying bacteria and functional genes, and the augmentation of Sulfuritalea and the secretion of biofilm protein stimulated by sulfur also played a synergistic role. This study provided a new potentially effective strategy to enhance advanced denitrification of wastewater of low C/N wastewater at low temperature.

Non-hydrogen processes for simultaneous desulfurization and denitrogenation of light petroleum fuels-an elaborative review.

The removal of sulfur- and nitrogen-containing compounds present in petroleum fractions is necessary to meet the stringent environmental regulations and to prevent the environment and humanity from the threats they pose. Conventional hydro-desulfurization and hydro-denitrogenation processes have evolved significantly over the past decade but are limited due to severe operating conditions and inefficiency in removing nitrogen-containing compounds. On the contrary, unconventional non-hydrogen methods for refining of crude oils are beneficial in terms of mild operating conditions and are efficient for eradicating both sulfur- and nitrogen-containing compounds. Despite being efficient for both sulfur and nitrogen-containing compounds, these techniques suffer due to the hindrance posed by the competitive nature of nitrogen-containing compounds. Thus, it is recommended to develop techniques that can remove both the compounds simultaneously and efficiently. Techniques for simultaneous removal of those compounds can also be expected to reduce the number of unit operations required during refining and can be energy-efficient as well. This elaborative review summarizes the developments done in this field in the past two decades. To improve the understanding of the scientific community towards the feasibility of simultaneous desulfurization and denitrogenation processes, the crucial parameters for efficient desulfurization-denitrogenation processes are also discussed. This review can be expected to encourage the scientific community to search for more economical, energy-efficient, and commercializable pathways for desulfurization-denitrogenation of petroleum oil.

Hantzsch Ester-Mediated Synthesis of Phenanthridines under Visible-Light Irradiation.

An efficient photocatalytic synthesis of phenanthridines mediated by an organo-photoredox initiator Hantzsch ester has been developed via denitrogenative intramolecular annulation of benzotriazolyl chalcones. The highly reducing photoactivated Hantzsch ester facilitates the transformation of benzotriazolyl chalcones into phenanthridinyl chalcones through photoinduced electron transfer (PET) and hydrogen atom transfer (HAT) processes. The mild reaction conditions utilizing inexpensive Hantzsch ester as photosensitizer, wide reaction scope and excellent functional group tolerance are notable attributes of the methodology.

Catalytic-oxidative/adsorptive denitrogenation of model hydrocarbon fuels under ultrasonic field using magnetic reduced graphene oxide-based phosphomolybdic acid (PMo-Fe3O4/rGO).

In this work, the effect of ultrasound irradiation on the catalytic oxidative/adsorptive denitrogenation (COADN) of model hydrocarbon fuels (composed of pyrroleor indoleas an organonitrogen compounds dissolved in n-nonane) has been investigated using magnetic reduced graphene oxide supported with phosphomolybdic acid (PMo-Fe3O4/rGO) as a heterogeneous catalyst/adsorbent and hydrogen peroxide as an oxidant. The synthesized PMo-Fe3O4/rGO nanocomposite was characterized by XRD, FE-SEM, VSM and BET surface area analysis methods. Moreover, different experimental variables including catalyst dose, initial pyrrole/indoleconcentration, H2O2 to pyrrole/indole molar ratio, ultrasound power and sonication time have been studied on the COADN process. The regeneration/recyclability of PMo-Fe3O4/rGO catalyst was also examined. Experimental results revealed that, the ultrasound treatment significantly improved the adsorption process of organonitrogen compounds from model fuels (qe increased by 50.3% for pyrrole and 18% for indole). Furthermore, high ultrasound-aided catalytic oxidative denitrogenation efficiency (85.6% for pyrrole and 90% for indole) has been attained under optimal conditions (ultrasonic power = 200 W, sonication time = 240 min, catalyst dose = 2 g/L, and H2O2:pyrrole/indole molar ratio = 5). The recyclability of catalyst displayed that the prepared catalyst can be reused five times without any significant reduction in its performance.

A novel strategy for accelerating the recovery of a Fe(II)-inhibited anammox reactor by intermittent addition of betaine: Performance, kinetics and statistical analysis.

In this manuscript, Fe(II) inhibition of anammox and its recovery were investigated, and the performance, kinetics and statistical features were comprehensively studied simultaneously. Anammox was suppressed and completely inhibited by the addition of 109.29 and 378.57 mg/L Fe(II), respectively, via uncompetitive inhibition. Nitrite inhibition of anammox was best fitted by the Edwards model and Aiba model. EDTA-2Na wash (0.5, 1.0, 1.5, and 2.0 mM) had a limited effect on anammox recovery, while the addition of 2.0 mM betaine accelerated anammox recovery. Prolonged betaine addition caused an unintended reduction of anammox activity, though it self-recovered after the withdrawal of betaine. The modified Boltzmann model most accurately simulated the processes of anammox recovery using the EDTA-2Na wash, betaine regulation and self-recovery, and the modified Stover-Kincannon model was able to assess the results of anammox recovery. The one-sample t-test was successfully applied to determine the effects of these three recovery strategies on inhibited anammox, which were short-term disinhibition or long-term recovery effects. The above-mentioned results demonstrate that an intermittent addition of betaine, which is a better alternative to frequently-used but poorly-degradable EDTA, may be a useful and environmentally friendly recovery strategy for Fe(II)-inhibited anammox reactor.

Enhanced long-term advanced denitrogenation from nitrate wastewater by anammox consortia: Dissimilatory nitrate reduction to ammonium (DNRA) coupling with anammox in an upflow biofilter reactor equipped with EDTA-2Na/Fe(II) ratio and pH control.

A long-term experiment in an anaerobic ammonium oxidation (anammox) reactor showed that anammox consortia could perform a stable and efficient Fe(II)-dependent dissimilatory nitrate reduction to ammonium (DNRA) coupled to the anammox (DNRA-anammox) process by controlling the EDTA-2Na/Fe(II) ratio and pH, with a total nitrogen removal rate (TNRR) of 0.23 ± 0.01 kg-N/m3/d. Anammox bacteria (Candidatus Kuenenia) were the dominant and functional microbes in such a nitrate wastewater treatment system. Visual MINTEQ analysis showed that the EDTA-2Na/Fe(II) molar ratio affected the influent composition of Fe and EDTA species and hence nitrate removal, while pH influenced both nitrate removal and the coupling degree of the Fe(II)-dependent DNRA-anammox process due to its own physiology. The kinetic simulation results showed that excess EDTA-2Na imposed a competitive inhibition on the Fe(II)-dependent DNRA-anammox process, and the Bell-shaped (A), (B), (C) and Ratkowsky models could be used to explore the pH dependency of the Fe(II)-dependent DNRA-anammox process.

A review on pyrolysis of protein-rich biomass: Nitrogen transformation.

Pyrolysis of protein-rich biomass, such as microalgae, macroalgae, sewage sludge, energy crops, and some lignocellulosic biomass, produces bio-oil with high nitrogen (N) content, sometimes as high as 10 wt% or even higher. Major nitrogenous compounds in bio-oil include amines/amides, N-containing heterocycles, and nitriles. Such bio-oil cannot be used as fuel directly since the high N content will induce massive emission of nitrogen oxides during combustion. The present review comprehensively summarized the effects of biomass compositions (i.e., elemental, biochemical, and mineral compositions) and pyrolysis parameters (i.e., temperature, heating rate, atmosphere, bio-oil collection/fractionation methods, and catalysts) on the contents of N and the N-containing chemical components in bio-oil. The migration and transformation mechanisms of N during the pyrolysis of biomass were then discussed in detail. Finally, the research gaps were identified, followed by the proposals for future investigations to achieve the denitrogenation of bio-oil.

Experimental, kinetic, and thermodynamic studies of adsorptive desulfurization and denitrogenation of model fuels using novel mesoporous materials.

The kinetics, equilibrium and thermodynamics studies of adsorptive desulfurization and denitrogenation to eliminate the refractory sulfur and nitrogen compounds like BT, DBT, quinoline and carbazole of model fuel by mesoporous material (MSU-S) and cobalt modified mesoporous material (CoO-MSU-S) adsorbents were carried out. The adsorption performance, capacity and selectivity of the adsorbent toward sulfur and nitrogen compounds were examined. Equilibrium and kinetics experiments confirmed that Co+2 impregnation would enhance the adsorption capacity of MSU-S. The results demonstrated that CoO-MSU-S led to a considerable improvement in the adsorption performance. The adsorption amounts reached 18.41, 21.20, 39.65 and 24.60 mg.g-1 for BT, DBT, quinoline and carbazole, respectively. The Langmuir isotherm model showed good fittings with the experimental equilibrium data for benzothiophene, dibenzothiophene and carbazole, and the data for quinoline was expressed well by the Freundlich for CoO-MSU-S adsorbent. Negative Gibbs free energy showed that all sulfur and nitrogen compounds were adsorbed spontaneously. The experimental data revealed that the pseudo-second-order model can describe the kinetics of adsorption of compounds on the adsorbent. The data obtained from the breakthrough curves indicated that DBT < BT < carbazole < quinoline order for the selectivity of modified adsorbent towards the adsorbates.

High Capacity Oil Denitrogenation over Azine- and Tetrazine-Decorated Metal-Organic Frameworks: Critical Roles of Hydrogen Bonding.

In this work, we demonstrate that rational decoration of pore walls of the metal-organic frameworks (MOFs) with azine and dihydro-tetrazine functions is a very practical strategy for high capacity removal of both neutral and basic nitrogen-containing compounds (NCCs) from model oil. Its performance is even much better than the MOFs with high surface area, open metal sites, and different functional groups such as amine, hydroxyl, carboxy, and sulfonate. For this aim, a number of isostructure functional MOFs (FMOFs) have been synthesized. Among them, TMU-5 (with formula [Zn(OBA)(BPDH)0.5] n·1.5DMF, where H2OBA = 4,4'-oxybis(benzoic acid) and BPDH = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene) and TMU-34 (with formula [Zn(OBA)(H2DPT)0.5] n·DMF H2DPT = 3,6-di(pyridin-4-yl)-1,4-dihydro-1,2,4,5-tetrazine) show high affinity toward neutral and basic NCCs, respectively. Dihydro-tetrazine-decorated TMU-34 shows good affinity toward basic NCCs [pyridine (PYD) and quinoline (QUI)] because of hydrogen bonding of dihydro-tetrazine (-NH)···(N) basic NCCs. TMU-34 can adsorb about 619 and 632 mg g-1 PYD and QUI, respectively. On the other hand, azine-methyl-functionalized TMU-5 shows very high affinity to neutral NCCs [pyrrole (PRR) and indole (IND)] owing to strong hydrogen bonding of azine-methyl (Me-C═N-N═C-Me)···(NH) neutral NCCs. TMU-5 can adsorb 518 and 578 mg g-1 PRR and IND, respectively. These numbers are among the best reported data in this area and even reveal higher significance of the host-guest interaction when we consider moderate surface of these FMOFs. These results have been achieved by our "application-directed cavity functionalization" approach through decoration of MOF structures by suitable organic functional groups for specific purposes.