Degradation Of Aniline Research Articles

Efficient treatment of aniline containing wastewater in bipolar membrane microbial electrolysis cell-Fenton system

Aniline-containing wastewater can cause significant environmental problems and threaten the humans's life. However, rapid degradation of aniline with cost-efficient methods remains a challenge. In this work, a novel microbial electrolysis cell with bipolar membrane was integrated with Fenton reaction (MEC-Fenton) for efficient treatment of real wastewater containing a high concentration (4460 ± 52 mg L−1) of aniline. In this system, H2O2 was in situ electro-synthesized from O2 reduction on the graphite cathode and was simultaneously used as source of OH for the oxidation of aniline wastewater under an acidic condition maintained by the bipolar membrane. The aniline was effectively degraded following first-order kinetics at a rate constant of 0.0166 h−1 under an applied voltage of 0.5 V. Meanwhile, a total organic carbon (TOC) removal efficiency of 93.1 ± 1.2% was obtained, revealing efficient mineralization of aniline. The applicability of bipolar membrane MEC-Fenton system was successfully demonstrated with actual aniline wastewater. Moreover, energy balance showed that the system could be a promising technology for removal of biorefractory organic pollutants from wastewaters.

Influence mechanisms of textile-dyeing sludge characteristics on degradation of anilines by integrated ultrasound-permanganate treatment

In order to support the use of integrated ultrasound-Mn(VII) for the removal of anilines, this study investigated for the first time the influence of the sludge characteristics on the reaction kinetics of target anilines including o-toluidine, p-chloroaniline, 2-methoxy-5-methylaniline, and 2,4,5-trimethylaniline. The results indicated that with a KMnO4 dosage of 1 mM and an ultrasound power density of 0.90 W cm−3, 68.85%, 85.53%, and 78.50% of anilines can be removed from textile sludge plant 1, 2, and 3. Higher removal efficiency of anilines was achieved at a lower pH value, smaller particle size, and more negative ζ-potential. The target anilines exhibited substantial reactivity toward Mn(VII) with the maxima of second-order rate constants at a pH value near their pKa values for o-toluidine (0.80 M−1s−1 at pH 4), p-chloroaniline (0.65 M−1s−1 at pH 4), 2-methoxy-5-methylaniline (0.45 M−1s−1 at pH 4), and 2,4,5-trimethylaniline (0.34 M−1s−1 at pH 5). Moreover, the biodegradability of textile-dyeing sludge was greatly enhanced by integrated ultrasound-Mn(VII) treatment. This integrated treatment was proposed as an effective method for the disposal of anilines in textile-dyeing sludge.

Photocatalytic degradation of aniline in water using CuO nanoparticles

The removal of aniline as a carcinogen from aqueous environments is highly significant. In the present study, the feasibility of photocatalytic degradation of aniline by CuO nanoparticles was evaluated. A batch reactor with an internal UV lamp was used and the effects of the parameters of pH (3–11), dosage of catalyst (0.01–0.1 g/L), initial concentration of aniline (50–250 mg/L), and duration of reaction (15–90 min) were investigated. The remaining concentration of aniline was determined by spectrophotometer at the wavelength of 198 nm. The Langmuir–Hinshelwood model was used for examining the kinetics of the reaction. The results showed that the degradation of aniline is maximum at pH 7. Also, the removal efficiency of 90.16% after 90 minutes of reaction in the case of initial concentration of 50 mg/L was obtained. The aniline degradation was elevated from 40 to 82% by increasing CuO nanoparticles’ dosage from 0.01 to 0.1 g/L. In addition, the obtained data properly fit with the Langmuir–Hinshelwood kinetic model and showed that the K app decreased from 0.029 to 0.016 min −1 by increasing of the initial concentration of aniline. Considering the obtained results, the UV/CuO process can be an effective method for removing aniline from aqueous solution.

Identification and Characterization of a High Efficiency Aniline Resistance and Degrading Bacterium MC-01.

Biodegradation is one of the important methods for the treatment of industrial wastewater containing aniline. In this paper, a degrading bacterium named MC-01, which could survive in high concentration aniline wastewater, was screened from industrial wastewater containing aniline and sludge. MC-01 was preliminarily identified as Ochrobactrum sp. based on the amplified 16S rDNA gene sequence and Biolog system identification. MC-01 was highly resistant to aniline. After 24-h culture under aniline concentration of 6500mg/L, the amount of bacterium survived still remained 0.05×106CFU/mL. Experiments showed that there was no coupling expression between the growth of MC-01 and aniline degradation. The optimum growth conditions in LB culture were pH 6.0, 30°C of temperature, and 4% of incubation amount, respectively. And the optimum conditions of aniline degradation of MC-01 were pH 7.0, 45°C of temperature, and 3.0% of salt concentration, respectively. The degradation rate of MC-01 (48h) in different aniline concentrations (200~1600mg/L) was stable under the optimum conditions, which could reach more than 75%.

Aniline degradation from aqueous solution using electro/Fe2+/peroxydisulphate process

Non-degradation compounds are nowadays not being disposed into the environment, or are removed before being disposed into the environment. The aim of this study was to assess the degradation of aniline from aqueous media by electro/Fe2+/peroxydisulphate (PDS) process. The effects of different parameters like pH (3-9), electric current (EC; 10-30 mA/cm(2)), dose of PDS (10-40 mM), Fe2+ dose (5-20 mM) and initial aniline concentration (20-100 mg/L) on the degradation of aniline were investigated in the laboratory reactor in the batch condition. The results showed that the removal efficiency of aniline decreased by increasing the initial pH and pollutant concentration; however, with increasing EC and PDS doses and ferrous concentration, the removal efficiency increased. The maximum of aniline degradation, equalling 83%, was obtained at 60 min of reaction time. Also, for reaction time of 60-min runs, PDS only, EC only, PDS + Fe, PDS + EC and PDS + Fe + Fe, respectively, have 8.9%, 53%, 43%, 65% and 83% of the removal efficiency. The degradation efficiency of aniline from synthetic wastewater was significantly improved when the combined processes PDS/electro-conduction/Fe2+ was applied. Keywords Author Keywords:Aniline; Degradation; Sulphate radical; Iron; Peroxydisulphate

The treatment of aniline in aqueous solutions by gamma irradiation

AbstractA laboratory investigation of the radiation-induced degradation of aniline by gamma irradiation is the subject of this paper. During the inquiry, several aqueous samples with aniline concentrations of 25, 50, 75, 100 and 200 mg/L were irradiated for 5, 10, 15, 20, 25 and 30 h, respectively, by a

Oxidative degradation of aniline and benzotriazole over PAC@FeIIFe2IIIO4: A recyclable catalyst in a heterogeneous photo-Fenton-like system

Abstract A mesoporous composite PAC@FeIIFe2IIIO4 was synthesized, characterized and employed as an efficient heterogeneous catalyst for aniline (An) and benzotriazole (BTA) degradation in the photo-Fenton oxidation process. The response surface methodology (RSM) with central composite design (CCD) was employed in order to evaluate the influence and interactions of the operating parameters in photo-Fenton system. Under optimum conditions, the findings of experiments indicated that the presence of An and BTA simultaneously had synergistic effects on the removal efficiency, and the degradation performance in the presence of the two pollutants was higher, compared with each of them alone. The removal efficiencies of 70.4 and 99.5% were obtained for An and BTA after five successive cycles of use, demonstrating the catalytic activity of PAC@FeIIFe2IIIO4 was preserved effectively even after five cycles of use owing to its good stability. The degradation of both pollutants followed pseudo-first-order kinetic model. The obtained results of mineralization experiments revealed that photo-Fenton system not only improved the biodegradability, but also could provide proper conditions for biological process. Therefore, PAC@FeIIFe2IIIO4 could be considered as an efficient and cost-effective catalyst for the purification of contaminated waters containing multi-pollutants ecosystem.

Direct fabrication of lamellar self-supporting Co3O4/N/C peroxymonosulfate activation catalysts for effective aniline degradation

N-doped carbon materials have great potential as functional materials for water pollution control. However, the synthesis of green and sustainable N-doped carbon catalysts face numerous challenges. This study uses a thermal treatment by directly heating a homogeneous mixture of cobalt acetate and dimethylglyoxime to synthesize lamellar ordering Co3O4/N/C compounds. Dimethylglyoxime was chosen to play duple roles as both nitrogen and carbon source. The obtained N-doped carbon material was used as a catalyst for effective aniline degradation by activating peroxymonosulfate (PMS). In this approach, nanomaterials with good catalytic performance, high stability, and magnetic property can be obtained, which facilitate recycle convenience. In this study, graphitic N is found to improve electron mobility, and the lone pair of pyrrolic-like N electrons tends to form effective Co-N4 moieties with Co species, which can increase the catalyst activity. Therefore, the prepared catalyst has higher activity than individual Co3O4. Furthermore, the effects of N-doped carbon materials on aniline degradation by activated PMS and the proposed reaction pathways for the mineralization of aniline were explain in detailed.

Electrochemical oxidation of aniline by a novel Ti/TiOxHy/Sb-SnO2 electrode

Electrochemical oxidation of aniline in aqueous solution was investigated over a novel Ti/TiOxHy/Sb-SnO2 electrode prepared by the electrodeposition method. Scanning electron microscopy, X-ray diffraction, and electrochemical measurements were used to characterize its morphology, crystal structure, and electrochemical properties. Removal of aniline by the Ti/TiOxHy/Sb-SnO2 electrode was investigated by ultraviolet-Visible spectroscopy and chemical oxygen demand (COD) analysis under different conditions, including current densities, initial concentrations of aniline, pH values, concentrations of chloride ions, and types of reactor. It was found that a higher current density, a lower initial concentration of aniline, an acidic solution, the presence of chloride ions (0.2 wt% NaCl), and a three-dimensional (3D) reactor promoted the removal efficiency of aniline. Electrochemical degradation of aniline followed pseudo-first-order kinetics. The aniline (200 mL of 100 mg L−1) and COD removal efficiencies reached 100% and 73.5%, respectively, at a current density of 20 mA cm−2, pH of 7.0, and supporting electrolyte of 0.5 wt% Na2SO4 after 2 h electrolysis in a 3D reactor. These results show that aniline can be significantly removed on the Ti/TiOxHy/Sb-SnO2 electrode, which provides an efficient way for elimination of aniline from aqueous solution.

Natural Attenuation of Nonvolatile Contaminants in the Capillary Fringe

When anoxic polluted groundwater encounters the overlying vadose zone an oxic/anoxic interface is created, often near the capillary fringe. Biodegradation of volatile contaminants in the capillary fringe can prevent vapor migration. In contrast, the biodegradation of nonvolatile contaminants in the vadose zone has received comparatively little attention. Nonvolatile compounds do not cause vapor intrusion, but they still move with the groundwater and are major contaminants. Aniline (AN) and diphenylamine (DPA) are examples of toxic nonvolatile contaminants found often at dye and munitions manufacturing sites. In this study, we tested the hypothesis that bacteria can aerobically biodegrade AN and DPA in the capillary fringe and decrease the contaminant concentrations in the anoxic plume beneath the vadose zone. Laboratory multiport columns that represented the unsaturated zone were used to evaluate degradation of AN or DPA in contaminated water. The biodegradation fluxes of the contaminants were estimated to be 113 ± 26 mg AN·m(-2)·h(-1) and 76 ± 18 mg DPA·m(-2)·h(-1) in the presence of bacteria known to degrade AN and DPA. Oxygen and contaminant profiles along with enumeration of bacterial populations indicated that most of the biodegradation took place within the lower part of the capillary fringe. The results indicate that bacteria capable of contaminant biodegradation in the capillary fringe can create a sink for nonvolatile contaminants.

Photocatalytic ozonation of aniline with TiO2-carbon composite materials

The photocatalytic ozonation of aniline (ANL) aqueous solutions was carried out in the presence of neat titanium dioxide (TiO2), multi-walled carbon nanotubes (MWCNT) and a composite of TiO2 and MWCNT. Independent tests for catalytic ozonation and photocatalysis were also carried out in order to explore the potential occurrence of a synergetic effect. Photocatalytic and catalytic ozonation carried out with an ozone dose of 50 g m−3 converted ANL in 15 min. Photocatalysis using P25, commercial TiO2, and an 80:20 (w/w) composite of P25 and MWCNT also led to total ANL conversion, but at longer reaction times. Removal of TOC was higher than 70% for all photocatalytic ozonation systems at 1 h of reaction. With the exception of neat MWCNT, photocatalytic ozonation in the presence of the selected samples led to nearly complete mineralization after 3 h of reaction. Photocatalytic ozonation completely removed oxalic acid (OXA) formed during ANL degradation. The concentration of oxamic acid (OMA, other ANL degradation by-product more refractory than OXA) generally increased with time, and in the photocatalytic ozonation with P25 based materials its concentration decreased earlier. The presence of nitrates and ammonium was confirmed during ANL degradation by all tested treatments, with the exception of the cation in TiO2 catalysed reactions.

Degradation of aniline by heterogeneous Fenton's reaction using a Ni-Fe oxalate complex catalyst

A Ni-Fe oxalate complex catalyst was synthesized and characterized by means of Brunauer–Emmet–Teller (BET) method, scanning electron microscope (SEM) and X-ray photo-electron spectroscopy (XPS). The catalyst showed good catalytic activity for aniline degradation by heterogeneous Fenton's reaction, in which the synergetic index was 9.3. The effects of reaction temperature, catalyst dosage, hydrogen peroxide concentration and initial pH were investigated. Under the optimum conditions (T = 293 K, catalyst dosage = 0.2 g/L, H2O2 concentration = 4 mmol/L and initial pH = 5.4), 100% aniline could be removed within 35 min, and approximately 88% deamination efficiency was achieved in 60 min. The aniline degradation process followed the pseudo-first-order kinetic (k = 0.177 min−1) with activation energy (Ea) of 49.4 kJ mol−1. Aniline could be removed in a broad initial pH (3–8) due to the excellent pH-tolerance property of the catalyst. The detected ammonium ion indicated that deamination occurred during aniline degradation. It was proposed that deamination synchronized with aniline removal, and aniline was attacked by free radicals to generate benzoquinonimine and phenol. This system is promising for the removal of aniline from water.

Biodegradation of aniline by Enterobacter ludwigii KH-5 isolated from the soil around Shiraz refinery, Iran

<div> <p>Aniline is a harmful substance that pollutes the environment and seriously endangers human health. In the present study five different bacteria were enriched and isolated from the soil around Shiraz refinery (Iran) as aniline degrading bacteria. They were identified as <em>Enterobacter ludwigii </em>KH-5,<em> Raoultella planticola</em> KH-A2<em>, Alcaligenes faecalis</em> KH-A3<em>, Serratia marcescens</em> KH-A4 and<em> Microbacterium barkeri</em> KH-A1 based on 16S rDNA gene sequencing. The highest aniline degradation rate (96%) was observed by <em>E. ludwigii</em> KH-A5. This strain with the greatest amount of minimum inhibitory concentration (MIC) was the most aniline resistant bacterium. The optimum pH and temperature that supported biodegradation of aniline by strain KH-A5 were 7.0 and 28-35 °C, respectively. The maximum growth and biodegradation of aniline by KH-A5 were observed at the initial aniline concentration of 100 mg l<sup>-1</sup>. The strain could growth on aniline up to concentration of 700 mg l<sup>-1</sup> with the degradation rate of 11%. Further studies demonstrated that the addition of 0.5 g l<sup>-1</sup> glucose or potassium nitrate as a second carbon or nitrogen source could slightly enhance the biodegradation efficiency from 96.0% to 99.0%. However, even more addition of glucose or potassium nitrate could not further enhance the biodegradation process but delayed the biodegradation of aniline by the strain KH-A5. It could be concluded that these new strains, particularly<em> E. ludwigii</em> KH-A5, have a potential use for bioremediation of the site contaminated with aniline.</p> </div> <p> </p>

Constructing BiO1.1Br0.8 sheet-sphere junction structure for efficient photocatalytic degradation of aniline

A sheet-sphere junction structure photocatalyst, BiO1.1Br0.8 was successfully synthesized by calcining BiOBr at 500°C for 7h. The BiO1.1Br0.8 exhibited apparently enhanced photocatalytic activity in comparison with BiOBr. About 90% of aniline (50mL, 50mgL−1) was degraded over BiO1.1Br0.8 (1gL−1) after LED light irradiation for 4h. Photocurrent and photoluminescence spectra analyses demonstrated that separation efficiency of photogenerated electron-hole pairs in BiO1.1Br0.8 was much higher than that in BiOBr, which greatly improved its photocatalytic activity. The increased pore size of BiO1.1Br0.8 was beneficial for projecting light into pore, which promoted the photocatalytic degradation of aniline.

Electrocatalytic degradation of aniline by Ti/Sb–SnO2, Ti/Sb–SnO2/Pb3O4 and Ti/Sb–SnO2/PbO2 anodes in different electrolytes

Electrochemical treatment (ECT) of bio-refractory and highly toxic aniline was investigated over Ti/Sb–SnO2, Ti/Sb–SnO2/Pb3O4 and Ti/Sb–SnO2/PbO2 anodes in Na2SO4 or NaCl electrolyte, for the purpose of finding out the most suitable electrode in the two kinds of electrolyte. The degradation performances of aniline were investigated by UV–Vis spectra, chemical oxygen demand (COD) and biochemical oxygen demand (BOD). In addition, instantaneous current efficiency (ICE) and energy consumption (Ep) for aniline degradation were also studied. Results showed that the performances of aniline electrochemical oxidation at the three electrodes were significantly different, which also relied on the electrolytes. Ti/Sb–SnO2 showed the best effect on the degradation of aniline in Na2SO4 electrolyte. The aniline and COD removal efficiency could achieve 95.9% and 91.1%, respectively, at the lowest energy consumption after 5h electrolysis. While Ti/Sb–SnO2/Pb3O4 was more capable in NaCl electrolyte. The aniline and COD removal efficiency could achieve 97.7% and 96.8%, respectively, at the lowest energy consumption after 5h electrolysis. Ti/Sb–SnO2/PbO2 had the best capability to enhance the biodegradability in the both Na2SO4 electrolyte and NaCl electrolyte. The biodegradability (BOD5/COD) could be promoted from original 0.286 to 0.498 and 0.452, respectively. Moreover, it was found that the wastewater biotoxicity was also an important parameter to study the enhance biodegradability besides the effect of ring-opening or bond breaking. Furthermore, a simple mechanism of aniline degradation was proposed.

Efficacy of forming biofilms by Pseudomonas migulae AN-1 toward in situ bioremediation of aniline-contaminated aquifer by groundwater circulation wells.

The formation and activity of aniline-degrading biofilms developed by the psychrotrophic Pseudomonas migulae AN-1 were studied for the in situ remediation of contaminated aquifer using in-well bioreactor of groundwater circulating wells (GCWs). Biofilms grown in mineral salt medium with aniline exhibited tolerance to high concentrations of aniline. In aniline degradation rate, AN-1 biofilms exhibited slight differences compared with planktonic cells. The effectiveness and bio-implication of AN-1 biofilms in GCWs were investigated to treat aniline-contaminated aquifer. The results demonstrate that AN-1 biofilms survived the GCWs treatment process with high aniline-degrading efficiency. This system provides a novel environmentally friendly technology for the in situ bioremediation of low-volatile contaminants.

Characterization and biodegradation potential of an aniline-degrading strain of Pseudomonas JA1 at low temperature

Aniline is a common toxic compound in various industrial processes. It should be removed from effluents before their discharge into water bodies. A cold-tolerant bacterium JA1 capable of utilizing aniline as the sole source of carbon, nitrogen, and energy was isolated from activated sludge samples collected from a sewage treatment plant. The isolate was identified as Pseudomonas species by 16S rDNA sequence analysis. Strain JA1 was able to degrade less than 1600 mg l−1 aniline with high efficiency and grow well at pH varying from 5.0 to 9.0. The suitable temperature ranged from 10 to 35°C. Under optimal conditions (pH 7.0, 25°C), 800 mg l−1 of aniline was almost completely degraded within 24 h. Substrates utilization tests showed that the strain could grow well when sodium acetate, glucose, sodium citrate, benzene, aniline, phenol, nitrobenzene, and m-cresol acted as the sole source of carbon. The adaptation to wide range of aniline concentration, pH, temperature, and different substances made strain JA1 promising for aniline degradation from industrial wastewater.

Coupling of bio-PRB and enclosed in-well aeration system for remediation of nitrobenzene and aniline in groundwater.

A laboratory-scale bio-permeable reactive barrier (bio-PRB) was constructed and combined with enclosed in-well aeration system to treat nitrobenzene (NB) and aniline (AN) in groundwater. Batch-style experiments were first conducted to evaluate the effectiveness of NB and AN degradation, using suspension (free cells) of degrading consortium and immobilized consortium by a mixture of perlite and peat. The NB and AN were completely degraded in <3days using immobilized consortium, while 3-5days were required using free cells. The O2 supply efficiency of an enclosed in-well aeration system was assessed in a box filled with perlite and peat. Dissolved O2 (DO) concentrations increased to 8-12mgL(-1) in 12h for sampling ports within 12cm of the aeration well. A diffusion coefficient as 33.5cm(2)s(-1) was obtained. The DO concentration was >4mgL(-1) when the aeration system was applied into the bio-PRB system. The NB and AN were effectively removed when the aeration system was functional in the bio-PRB. The removal efficiency decreased when the aeration system malfunctioned for 20days, thus indicating that DO was an important factor for the degradation of NB and AN. The regain of NB and AN removal after the malfunction indicates the robustness of degradation consortium. No original organics and new formed by-products were observed in the effluent. The results indicate that NB and AN in groundwater can be completely mineralized in a bio-PRB equipped with enclosed in-well aeration system and filled with perlite and peat attached with degrading consortium.

Photodegradation of aniline in water in the presence of chemically activated halloysite

Photocatalytic degradation of aniline was investigated in aqueous solutions containing halloysite (Hal) nanotubes, chemically activated halloysite (AHal), and photocatalysts: TiO2 (anatase) and commercial titania P25, under UV illumination. Powder X-ray diffraction (XRD), UV–Vis/DR spectra and nitrogen adsorption isotherms were carried out to characterize the activated halloysite. The effects of the AHal and titania photocatalyst amount as well as aniline concentration were examined. It is observed that the photodegradation of aniline has a similar course in the presence of AHal and in the presence of P25 and TiO2, both with respect to the decomposition of aniline and in decreasing the amounts of photoproducts being formed during the irradiation of aniline. The photodegradation of aniline is clearly slower in presence of Hal nanotubes than for AHal and P25. The disappearance of aniline follows approximately according to the Langmuir–Hinshelwood kinetics. The values of rate photodegradation constant are decreasing in the following order: P25>TiO2>AHal>Hal nanotubes. These results have indicated that halloysite containing titanium dioxide could be employed during photocatalytic removal of aniline from the aqueous solution, similarly to commercial titania photocatalysts.

PHOTOCATALYTIC DEGRADATION OF ANILINE IN AQUEOUS SOLUTION USING ZnO NANOPARTICLES

Aniline is a priority pollutant, which is known as a toxic organic pollutant released as effluent from several industries. Several physicochemical methods have been used for degradation of this pollutant. In this study, photocatalytic degradation of aniline from synthetic wastewater by ZnO nanoparticle was considered. The effects of different variables, such as irradiation time, the amount of photocatalyst, initial pH values and initial concentration of pollutant on the photodegradation of aniline were investigated to find the optimum condition. A laboratory-scale batch photocatalytic reactor with a low pressure UV lamp in the center was used. Results showed that the photocatalytic system was highly efficient for degrading aniline in a reasonable time. No statistically significant changes for photodegradation of aniline was observed in different concentrations of ZnO, pH and irradiation times (Pvalue<0.05). The maximum degradation efficiency of aniline was 93.9% in 500 mg/L of ZnO and alkaline pH. The degradation kinetic of aniline, based on Langmuir-Hinshelwood mechanism, illustrated a pseudo first-order kinetic model with a rate constant of surface reaction equal to 3.04 mg/L.min, and adsorption equilibrium constant of 0.31 L/mg. As a conclusion, the photocatalytic process by using ZnO has great potential for aniline degradation in wastewaters.