Removal Of Aniline Research Articles

Efficient activation of peroxymonosulfate by 3D blocky sponge-supported spinel ferrite nanocomposites for convenient removal of aniline

Efficient activation of peroxymonosulfate by 3D blocky sponge-supported spinel ferrite nanocomposites for convenient removal of aniline

The potential application of agroforestry residues in the adsorption of aniline

A low-cost activated carbon based on agroforestry residues (AAC) was synthesized and characterized to remove aniline (AN), a healthy and environmentally toxic substance. The batch adsorption assays were used to assess the effect of contact time (1, 2, 6, 12, and 24 h), pH (2, 4, 6, and 8), and with 1, 5, and 10 mg/L AN concentration. The adsorption mechanism of AN on ACC and commercial carbons (GAP and PAC) was evaluated and compared through Langmuir, Freundlich, and Temkin isotherms. The results show that AN removal increases with decreasing pH, reaching a maximum removal capacity of AAC of 90 %. AAC resulted in similar efficiency to GAC > 90 % to 1 and 5 mg/L. Langmuir shows the best-fit model reaching an R2 of 0.98. These models explain that the adsorption mechanism of AN on ACC is homogeneous, and monolayer adsorption occurs, achieving a maximum capacity of 1.20 and 1.16 mg/g for ACC and PAC, respectively, with a possible endothermic mechanism suggested by Temkin. The results showed that AAC could be considered an effective and economical adsorbent in removing the AN.

Catalytic conversion of soluble aniline into insoluble N-phenylphenazine for wastewater treatments

Aniline, a common pollutant in industrial wastewater, requires an effective treatment method with minimal chemical usage. In this study, a two-stage catalytic oligomerization process has been developed to address this issue by converting soluble aniline into insoluble oligomers for wastewater treatment. In the first stage, aniline is oxidized using hydrogen peroxide (H2O2) and a green catalyst, iron tetraamido macrocyclic ligand (Fe-TAML) to form aniline tetramers or pentamers. In the second stage, these oligoanilines undergo further oxidation with H2O2 alone at a higher temperature, resulting in the formation of N-phenylphenazine or its derivatives. These macrocyclic compounds precipitate from the wastewater due to π− π stacking, allowing easy separation through decantation or gravity filtration. After process optimization, only 3 mg/L of Fe-TAML and 2 g/L of H2O2 are required to treat 1 g/L of aniline, achieving a remarkable 96.8% aniline removal efficiency and a 62.5% precipitate yield. This two-stage oxidation approach shows promise for treating aniline and similar aromatic compounds in real industrial wastewater.

Redundancy and resilience of microbial community under aniline stress during wastewater treatment

Aniline is one of the most toxic and widespread organic pollutants. Although biological treatment is cost-effective and generates minimal secondary pollution, microbial communities are significantly affected by high aniline concentrations, which result in low degradation efficiency. However, a comprehensive understanding of the microbial community response to aniline stress is lacking. Here, we performed a cyclic experiment with aniline concentrations (200, 600, 1200, 600, and 200 mg/L) to investigate the ability of microbial communities to recover their performance after exposure to high aniline concentrations. At aniline concentrations up to 600 mg/L, the bioreactor exhibited high aniline removal efficiency (almost 100 %). Comamonas, Zoogloea, and Delftia played crucial roles in removing aniline and microbial beta diversity changed. Additionally, alpha diversity and network complexity decreased with increasing aniline concentration, but these metrics recovered to their original levels when the aniline concentration was returned to 200 mg/L. Homogeneous and heterogeneous selection dominated microbial community assembly. Therefore, according to the observed variations in community structure and the recovery of keystones after aniline stress, microbial community redundancy and resilience are pivotal for ensuring system stability. Overall, this study provides valuable insights into the redundancy and resilience of microbial communities under aniline stress and establishes a scientific basis for managing and evaluating wastewater treatment plants.

Green synthesis of novel Zn0.5Ni0.5FeCrO4 spinel magnetic nanoparticles: Photodegradation of 4-nitrophenol and aniline under visible light irradiation

This study explores novel nanoparticles used in environmental remediation of 4-nitrophenol and aniline from wastewater bodies. The Zn0.5Ni0.5FeCrO4 magnetic nanoparticles (MNPs) were synthesized using tragacanth gel as a green, low-cost, and easy sol-gel method. The MNPs were characterized by XRD, XPS, FT-IR, VSM, TEM, EDX, FESEM, BET, DRS, and elemental mapping. The analysis demonstrated that nanoparticles have a spinel cubic structure, spatial distribution of the elements, ferromagnetic activity, narrow bandgap, and uniform morphology. Furthermore, effectiveness of the developed MNPs to degrade recalcitrant organic pollutants such as 4-nitrophenol (4-NP) and aniline under visible light exposure were studied. The results indicated 95% aniline and 80% of 4-NP were successfully degraded in 180 and 150 min, respectively. The total organic carbon (TOC) analysis revealed 65% and 54% removal of aniline and 4-NP. LC-MS was employed to elucidate the photodegradation mechanism and to identify the degradation products, including small fragmented molecules.

Unraveling the mechanisms and responses of aniline-degrading biosystem to salinity stress in high temperature condition: Pollutants removal performance and microbial community

To explore the intrinsic influence of different salinity content on aniline biodegradation system in high temperature condition of 35 ± 1 °C, six groups at various salinity concentration (0.0%–5.0%) were applied. The results showed that the salinity exerted insignificant impact on aniline removal performance. The low-level salinity (0.5%–1.5%) stimulated the nitrogen metabolism performance. The G5-2.5% had excellent adaptability to salinity while the nitrogen removal capacity of G6-5.0% was almost lost. Moreover, high throughput sequencing analysis revealed that the g__norank_f__NS9_marine_group, g__Thauera and g__unclassified_f__Rhodobacteraceae proliferated wildly and established positive correlation each other in low salinity systems. The g__SM1A02 occupying the dominant position in G5 ensured the nitrification performance. In contrast, the Rhodococcus possessing great survival advantage in tremendous osmotic pressure competed with most functional genus, triggering the collapse of nitrogen metabolism capacity in G6. This work provided valuable guidance for the aniline wastewater treatment under salinity stress in high temperature condition.

Electron transfer-mediated peroxymonosulfate activation through monoatomic Fe–pyridinic N4 moiety in biochar-based catalyst for electron-rich pollutants degradation in groundwater

Pollution of groundwater by electron-rich refractory organic pollutants (e-ROPs) is detrimental to ecological integrity and human health. Biochar (BC)-based single-atom Fe catalysts (Fe–SACs) triggering nonradical peroxymonosulfate (PMS) process has shown great potential in addressing this problem. Nevertheless, the successful formation and precise regulation of active sites on BC remain formidable challenges. Herein, co-pyrolysis of BC derived from shrimp shells and N-containing supramolecular organic frameworks with a hexagonal cavity structure of Fe3+–N3 (Fe–SOFs) was, for the first time, used to prepare an efficient and inexpensive BC-based Fe–SAC (Fe–MCA@SS). The Fe–N bond was successfully grafted from Fe–SOFs onto BC and subsequently transformed into monoatomic Fe–pyridinic N4. Moreover, Fe–MCA@SS successfully triggered an efficient nonradical PMS process, degrading 94.5 % of aniline (AN) within 5 min. Mediated electron transfer (MET) mechanism was primarily responsible for AN removal. MET was attributed to the following factors: the synergistic effect of the stronger chemical adsorption of PMS with an Fe atom in Fe–pyridinic N4 active sites, the higher redox potential of [Fe–MCA@SS/PMS]*, and the value of the lowest unoccupied molecular orbital of AN being larger than the value of highest occupied molecular orbital of [Fe–MCA@SS/PMS]*. This study sheds new light on the preparation of BC-based SACs catalyst with efficient nonradical oxidation ability and an excellent feasibility to remove electron-rich organic pollutants in groundwater.

Enhanced Removal of Antimony and Aniline from Wastewater by Combining Electrocoagulation with Peroxymonosulfate

Enhanced Removal of Antimony and Aniline from Wastewater by Combining Electrocoagulation with Peroxymonosulfate

Magnetic γ-Fe2O3/ZnO@CNTs synthesized by a green precipitation method for the degradation of aniline through photocatalysis coupling catalytic ozonation

Aniline is highly toxic and difficult to degrade by conventional biological treatment processes. Thus, more efficient processing technology needs to be developed. Photocatalysis coupling catalytic ozonation (PCO) could be a solution. In this study, a green precipitation method was used to synthesize a γ-Fe2O3/ZnO@CNT catalyst, which exhibits high activity for aniline PCO degradation and strong magnetic properties for rapid separation. Under the optimal conditions, the aniline removal rate reached 93.5%. After 5 reaction cycles, the γ-Fe2O3/ZnO@CNT catalysts can be separated easily with a magnet, and a 91% aniline removal rate can be maintained. Furthermore, there are at least 4 kinds of advanced oxidation processes (AOPs) in this system, i.e., (1) photocatalytic oxidation; (2) catalytic ozonation; (3) photocatalytic ozone; and (4) Fenton oxidation. Thus, a novel stable and magnetically separable catalyst was developed, and new insight were provided for the role of PCO processes in the treatment of aniline.

Oligomerization of aniline catalyzed by Iron-tetraamidomacrocyclic ligand (Fe-TAML) near neutral pH

Aniline is a nitrogen-containing compound that contributes to both total organic carbon (TOC) and total nitrogen (TN) in wastewaters. Herein, we focus on converting aniline into oligomers, which aggregate into solid particles and can be separated from the wastewaters. By using this strategy, we can remove not only aniline but also TOC and TN in the wastewater without producing any secondary wastes. In this reaction, aniline is first reacted with H2O2 in the presence of Iron-tetraamidomacrocyclic ligand (Fe-TAML) near a neutral pH. Only 800 ppm of H2O2 and 2 ppm of Fe-TAML are needed to react with 1000 ppm of aniline at pH 8. After 2 days of reaction, solid particles are produced, and they can be filtered out with a membrane. The treatment efficiency can be further improved by lowering the pH to 6. Under this condition, the solid particles are big enough to settle under gravity in one day. After that, the top-layer solution can be separated from the solid particles. Following the oxidation- settling strategy, aniline, TOC, and TN of the decanted solution are reduced to 27.0, 99.0, and 29.0 ppm, respectively. This new strategy is effective in aniline removal with minimal H2O2 and catalyst usages.

Mass transfer fundamentals in pervaporation, perstraction and sorption: A unified approach

The high affinity between an organic solute and a polymeric sorbent or membrane is the basis for separating organic contaminants from water via sorption, pervaporation and perstraction. These processes all share the same features of dissolution and diffusion, and thus their mass transfer characteristics can be correlated. However, they are often dealt with independently, and the research findings from one process are rarely applied to the other. The permeability coefficient in perstraction (for liquid permeation) based on concentration gradient as the driving force for mass transfer and the permeability coefficient for pervaporative transport expressed customarily in analog to vapor permeation can hardly be compared directly, and sometimes seemingly contradictive trends in temperature dependencies of the permeability coefficients for the two process modes may result. Looking into the mass transfer fundamentals pertaining to sorption, pervaporation and perstraction, this work attempted to provide a unified approach to the mass transfer in all these processes. While the permeability coefficient in pervaporation uses equivalent vapor pressure gradient across the membrane as the driving force, this work provided a generalized treatment by taking into account the sorption constants embedded in the permeability coefficients of the different processes so that the performance parameter for one process could be applied to another, which would be especially useful for screening and developing appropriate membrane/sorbent materials. In addition, the relationships among the selectivities of these separation processes were elucidated, which allowed for an intuitive illustration of how the process selectivity changed due to the process mode. Aniline removal from water via pervaporation, perstraction and sorption using a poly(ether-b-amide) membrane/sorbent was used as an example to illustrate and validate the approach.

Effect of pumping-induced soil settlement on the migration and transformation of aniline

This study selected a contamination site associated with pesticide production to investigate the impact of soil settlement induced by pumping on the migration and transformation of the principal pollutant, aniline. The TMVOC model was enhanced by incorporating the settlement effect and validated through a soil-column experiment, which examined aniline distribution, phase transformation, and remediation efficiency under soil settlement. The results indicate that the optimized TMVOC model can accurately simulate the impact of pumping-induced soil settlement on aniline removal. The longitudinal migration of aniline was reduced, with the area of high concentrations drawing nearer to the surface. Furthermore, soil settlement negatively affected the removal of aniline in the Non-Aqueous Phase Liquid (NAPL) phase, resulting in a 10.59 % decline in the removal rate. In contrast, soil settlement positively influenced aniline removal in the gas and aqueous phases, increasing the removal rate by 12.55 % and 5.04 %, respectively, with the gas phase showing the most significant increase. Soil porosity decreased due to soil settlement, leading to a change in the proportion of each phase, with NAPL increasing after remediation. Additionally, soil settlement exhibited hysteresis, as evidenced by a noticeable decrease in the removal rate in the 10th month of the remediation process, and the final mass removal rate was reduced by 5.93 %.

Deciphering the role of hydraulic retention time (HRT) in integrated fixed-film activated sludge (IFAS) system under aniline stress: Effects on microbial succession and communication

Integrated fixed-film activated sludge (IFAS) system offered an energy-efficient option for nitrogen removal from aniline wastewater. The regulation of hydraulic retention time (HRT) has been reported to affect the fate of functional microbial communities with different generation cycles, but the role of HRT in IFAS under aniline stress has not been sufficiently revealed. Herein, it was observed that shortening the HRT altered the mechanisms underlying the adaptation of a continuous flow micro-aerated IFAS system to aniline stress, thereby negligibly impacting the removal of aniline. The total nitrogen removal rate in Y2 (HRT = 0.5 day) was 40.28 % higher than Y1 (1 day), and 23.7 % higher than Y3 (0.25 day). This could be attributed to Y2 having an ample supply of electron donors for denitrification compared to Y1, as well as showing weaker stress to inhibit nitrification compared to Y3. Furthermore, with the progressive intensification of stress induced by HRT reduction, microorganisms gradually enhanced their adaptation to aniline. This led to an increased migration of microorganisms towards the inner layers of the biofilm, resulting in enhanced functional complementarity between the sludge and biofilm in Y2. Also, there was a distinct development of autotrophic denitrification, with arenimonas predominant in Y1, and Thauera predominant in Y2 and Y3. Moreover, Y2 possessed a high abundance of functional genes related to the production and reception of quorum sensing signal molecules, which may enhance the electron transport-dependent nitrogen metabolism reaction.

Micromotor-assisted bifunctional platform for efficient detection and removal of aniline

A novel and facile strategy was applied in the design and fabrication of a micromotor-assisted dual-functional platform for the sensitive detection and rapid removal of aniline in water.

Preparation of magnetic surface molecularly imprinting polymers based on glycidyl methacrylate as selective sorbents for aniline removal from aqueous medium

In this paper, two molecularly imprinted polymers (MIPs) based on glycidyl methacrylate were synthesized by radical suspension polymerization and surface imprinting method in the presence of silica-coated magnetic nanoparticles. Ethylenediamine (eda) and triethylentetramine (teta) were used for surface imprinting. The samples were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and mercury porosimetry. The sorption and desorption behaviors of two MIPs as an aniline sorbent from aqueous solutions were evaluated. Sorption studies were carried out in the pH range of 2.0 - 10.0, and maximum sorption capacities were attained at pH 6.0. Also, the effect of different desorption agents were examined and acetonitrile was chosen as the best desorbing eluent for aniline. The obtained MIPs were regenerated in four sorption/desorption cycles, and the results show that these two MIPs could be reusable as sorbents for removing aniline from polluted wastewater.

Synergizing redox of zerovalent iron and singlet oxygen to remove aniline, chromium and antimony in printing and dyeing wastewater synchronously: Multifunctional effect of sludge derived biochar

Printing and dyeing wastewater (PDW) with complex water matrix generally contains ubiquitous organic pollutant (e.g., aniline) and heavy metals (e.g., Cr(VI) and Sb(III)), aggravating their environmental risks and remediation difficulty. To date, little is known about the synchronous removal of aniline, Cr(VI) and Sb(III) because ternary processes including oxidation, reduction and adsorption need to function synchronously. Herein, we proved multiple redox active centers (e.g., Fe-containing moieties, C-containing moieties and PFRs) present in sludge derived biochar (SDBC), which ensured synchronous degradation of aniline, reduction of Cr(VI) and oxidation of Sb(III) over a wide pH range. Results demonstrated that degradation of aniline was mainly attributed to singlet oxygen (1O2), originating from activating O2 to O2− and 1O2 by SDBC without any external oxidants. Cr(VI) was reduced to Cr(III) by reductive active species (i.e., O2− and Fe-containing moieties: zerovalent iron (Fe(0)) and Fe(II)), while Fe(0) triggered the dominant Cr(VI) reduction. The conversion of Sb(III) to Sb(V) was ascribed to Fe(III) and C = O moiety, and Fe(III) supported the major Sb(III) oxidation. The generated Cr(III) and Sb(V) could be further immobilized onto SDBC through electrostatic attraction, complexation and precipitation. Overall, this study provides a novel understanding on recycling sewage sludge to functional biochar accompanied by carbon-storage, while offering a promising strategy for the simultaneous removal of multicomponent contaminants in practical PDW.

Assessment of the Pressure Driven Membrane for the Potential Removal of Aniline from Wastewater

Assessment of the Pressure Driven Membrane for the Potential Removal of Aniline from Wastewater

An internal circulation iron–carbon micro-electrolysis reactor for aniline wastewater treatment: Parameter optimization, degradation pathways and mechanism

Aniline is a vital industrial raw material. However, highly–toxic aniline wastewater usually deteriorated effluent quality, posed a threat to human health and ecosystem safety. Therefore, this study reported a novel internal circulation iron–carbon micro-electrolysis (ICE) reactor to treat aniline wastewater. The effects of reaction time, pH, aeration rate and iron–carbon (Fe/C) ratio on the removal rate of aniline and the chemical oxygen demand were investigated using single-factor experiments. This process exhibited high aniline degradation performance of approximately 99.86% under optimal operating conditions (reaction time = 20 min, pH = 3, aeration rate = 0.5 m3·h−1, and Fe/C = 1:2). Based on the experimental results, the response surface method was applied to optimize the aniline removal rate. The Box–Behnken method was used to obtain the interaction effects of three main factors. The result showed that the reaction time had a dominant effect on the removal rate of aniline. The highest aniline removal rate was obtained at pH of 2, aeration rate of 0.5 m3·h−1 and reaction time of 30 min. Under optional experimental conditions, the aniline content of effluent was reduced to 3 mg·L–1 and the removal rate was as high as 98.24%, within the 95% confidence interval (97.84%–99.32%) of the predicted values. The solution was treated and the reaction intermediates were identified by high–performance liquid chromatography, ultraviolet–visible spectroscopy, Fourier–transform infrared spectroscopy, gas chromatography–mass spectrometry, and ion chromatography. The main intermediates were phenol, benzoquinone, and carboxylic acid. These were used to propose the potential mechanism of aniline degradation in the ICE reactor. The results obtained in this study provide optimized conditions for the treatment of industrial wastewater containing aniline and can strengthen the understanding of the degradation mechanism of iron–carbon micro-electrolysis.

Understanding the impacts of intermittent electro field on the bioelectrochemical aniline degradation system: Performance, microbial community and functional enzyme

On account of the lack of a sustainable electron donor source and the inhibitory effect of aniline on denitrogenation make it tough to achieve simultaneous removal of aniline and nitrogen. Herein, the strategy of adjusting electric field mode was applied to the electro-enhanced sequential batch reactors (E-SBRs: R1 (continuous ON), R2 (2 h-ON/2 h-OFF), R3 (12 h-ON/12 h-OFF), R4 (in the aerobic phase ON), R5 (in the anoxic phase ON)) to treat aniline wastewater. Aniline removal rate reached approximately 99% in the five systems. Decreasing electrical stimulation interval from 12 to 2 h significantly improved the electron utilization efficiency for aniline degradation and nitrogen metabolism. The total nitrogen removal was achieved from 70.31% to 75.63%. Meanwhile, the hydrogenotrophic denitrifiers of Hydrogenophaga, Thauera, and Rhodospirillales, enriched in reactors of minor electrical stimulation interval. Accordingly, the expression of functional enzyme related to electron transport was incremental with the proper electrical stimulation frequency.

Nitrogen and sulfur co-doped porous carbon derived from polypyrrole-polythiophene for efficient peroxydisulfate activation towards degradation of aniline

To enhance the catalytic activity of carbon materials and streamline their synthesis process, it is necessary to optimize the doping of heteroatoms and reduce the dependence on organic solvents. This can be achieved by utilizing carbonized Polypyrrole-Polythiophene (C(Ppy-Pth)), which is obtained through simultaneous and in-situ co-doping of N and S. This material can serve as an effective activator of peroxydisulfate (PDS) for the degradation of aniline (AN). The results showed that Ppy-Pth could be efficiently synthesized by using cetyltrimethyl ammonium bromide, pyrrole, thiophene, FeCl3, and H2O2 in water. Based on the price, self-decomposition and oxidation efficiency, the performance of PDS activated by C(Ppy-Pth) was superior to that of peroxymonosulfate (PMS) in degrading AN. The optimum conditions for catalyzing PDS and degrading 30 mg/L AN by C(Ppy-Pth) were 0.10 g/L C(Ppy-Pth)-1000-1/1, 2.10 mM PDS, and pH0 = 3.00, which resulted in 86.69% AN removal in 30 min. Carbonation temperature, N/S ratio and pyridine N content are the key factors affecting the catalytic activity of C(Ppy-Pth). Quenching, probe, and electrochemical experiment revealed that in the catalytic PDS system with C(Ppy-Pth)-1000-1/1 (pH0 = 3.00), the oxidation of AN mainly occurred through the generation of hydroxyl radical (·OH), superoxide anion (O2·-), and electron transfer on the C(Ppy-Pth)-1000-1/1 surface. The steady-state concentration of ·OH and O2·- were 2.65 × 10−14 M and 1.97 × 10−13 M, respectively, and the contribution rate of ·OH oxidation was 31.28%. The oxidation of AN by sulfate radical (SO4·-) and singlet oxygen (1O2) could be neglected. This study provides a promising strategy for the construction of PDS catalyst and wastewater treatment.