Degradation Of Acrylonitrile Research Articles

Enhanced 3D electrochemical degradation of acrylonitrile with Fe-Cu@CB nanoparticles via the hydrogenation-oxidation synergistic processes

Acrylonitrile is a highly toxic and hazardous pollutant present in industrial wastewater at high concentrations, posing significant environmental and health risks. There is an urgent need for efficient, cost-effective, and environmentally friendly treatment methods for acrylonitrile. The electron-withdrawing –CN group in acrylonitrile offers potential pathways for degradation via superoxide radicals (O2•-), but this approach remains underexplored with limited research efforts. To investigate the degradation mechanism of acrylonitrile by O2•-, we synthesized particle electrodes Fe-Cu@CB using a novel one-step co-hydrolysis method and applied them for the 3D electrochemical degradation of acrylonitrile. Batch experiments showed that acrylonitrile with an initial concentration of 100 mg·L−1 was removed by 95 % at a voltage of 2.73 V (vs. RHE) for one hour. Compared with 2D electrochemical degradation, 3D electrochemical degradation of acrylonitrile increased the removal rate from 57 % to 95 %, and the TOC removal rate was also enhanced from 23.59 % to 88.33 %. Additionally, the energy consumed by this system was remarkably lower than the reported 3D electronic reaction system. Based on electron paramagnetic resonance (EPR), oxygen species (ROS) quenching experiments, and GC–MS results, we proposed a new hydrogenation-oxidation synergistic pathway for acrylonitrile removal, which could be depicted as that acrylonitrile suffered hydrogenation, followed by O2•- reduction, and finally the intermediate products were degraded speedily. Other pollutants in acrylonitrile wastewater such as acrylic acid, acrylamide, and fumaronitrile could also be eliminated in this reaction system, and the degradation efficiency varied with the electronic structure of the pollutants. These findings offer new insights into the treatment of acrylonitrile wastewater and present a highly efficient, sustainable solution for industrial pollutant degradation.

Ultrasound-induced PMS activation for acrylonitrile degradation with series LTZ perovskite-like catalysts: Synergistic and mechanistic insight

The degradation of toxic and refractory pollutants requires an efficient, environmentally friendly, and cost-effective treatment process to address the current challenges associated with wastewater. Herein, we present a hybrid system (LaTixZn1−xO3/PMS/US) that utilizes ultrasound irradiation to activate PMS (peroxymonosulfate) for the degradation of acrylonitrile. The system incorporates a series of perovskite-like catalysts LaTixZn1−xO3 (x = 0.2, 0.4, 0.6, 0.8, 1) fabricated using citric sol-gel method. The texture properties, surface morphology and composition of synthesized catalysts were analyzed by TEM, FESEM/EDS, FTIR, XRD and XPS. Furthermore, influences of operation parameters such as catalyst dose, PMS dose, pH, and US power, co-existing anions were investigated along with PMS utilization efficacy and its consumption rate. Under the optimal conditions, catalyst 0.75LTZ exhibited remarkable catalytic activity for acrylonitrile degradation (98.7%), with synergistic index value (3.363). The trapping experiments and EPR analysis revealed that ROS (SO4•− and •OH) both played a pivotal role in acrylonitrile removal, accordingly a rational mechanism was elucidated. The co-existing ions species HCO3– showed a strong inhibitory effect on acrylonitrile degradation compared to other ionic species (NO3–, Cl–, and SO42–). Based on the GC-MS analysis and existing literature, four possible pathways for the degradation of acrylonitrile were suggested. The treatment process incurred a cost of around 0.081$ per liter of wastewater in the 0.75LTZ/PMS/US system.

Nitrogen–Fluorine co-doped TiO2/SiO2 nanoparticles for the photocatalytic degradation of acrylonitrile: Deactivation and regeneration

In this study, we investigated the deactivation kinetics and mechanism of N–F–TiO2/SiO2 nanopowder as a model photocatalyst for the purpose of facilitating the photocatalytic degradation of acrylonitrile (AN) in aqueous environment. Prior research has already displayed the proficient degradation of AN through the utilization of N–F–TiO2/SiO2 catalysts, revealing a degradation efficiency of 81.2% within a span of 6 min at an initial AN concentration of 10 mg/L. Multiple variables including the initial AN concentration, illumination intensity, and initial pH value were extensively analyzed during the degradation process. The kinetics of photocatalytic degradation of AN, facilitated by the N–F–TiO2/SiO2 photocatalyst, were modeled by fitting the pseudo first-order reaction kinetics to each individual factor. Furthermore, the adverse effect of catalyst poisoning during the photocatalytic breakdown of AN using the N–F–TiO2/SiO2 photocatalyst was analyzed through a range of different techniques including SEM, XPS, BET, XRD, TG, and NH3-TPD. The incorporation of findings from these diverse techniques revealed that, the primary factors contributing to the photocatalyst's poisoning were as follows: (i) During the degradation process, the build-up of intermediate molecules on active sites hindered their functionality, leading to a decrease in the efficiency of the photocatalytic reaction, (ii) Carbonaceous deposits formed when the catalyst's pore structure was obstructed by pollutants or intermediate products that had not undergone timely photocatalytic breakdown and (iii) The persistent erosion of active sites due to hydraulic forces resulted in inadequate performance of the N–F–TiO2/SiO2 photocatalyst in aqueous solutions. A comprehensive analysis of the deactivation kinetics was conducted, deciding in the formulation of a detailed poisoning mechanism for the N–F–TiO2/SiO2 photocatalyst. Additionally, we explored the catalysts regeneration, involving thermal treatment, ultrasonic irradiation, and catalyst reloading. This study not only advances our insight into the waning performance of catalysts in aqueous media but also establishes a conceptual framework for extrapolating analogous deactivation dynamics in other catalysts, grounded in precedent experimental knowledge. This research contributes to the development of a deactivation model for catalysts in the aqueous environment, based on existing experimental research, providing a theoretical framework for understanding the deactivation process of photocatalysts.

Mechanistic approach of SO4•−/•OH radical toward target pollutants degradation simultaneously enhanced activity and stability of perovskite-like catalyst SrCuxNi1-xO3

• A novel catalyst SrCu x Ni 1-x O 3 were synthesized by citric solgel method. • In-situ generated reactive species SO 4 •– and • OH both play major role on degradation. • Treatment system 0.6SCN/PMS provided very low treatment cost 50.72 $/m 3 of aqueous solution. • The possible degradation pathways of acrylonitrile and acrylamide were proposed. In this study, the degradation of highly toxic pollutants acrylonitrile (ACN) and acrylamide (ACM) by peroxymonosulfate (PMS) activation with series perovskite-like catalyst SrCu x Ni 1-x O 3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) were studied systematically in the batch experiments. Synthesized catalysts were characterized by various analytical techniques e.g., XRD, FTIR, FESEM with EDAX, TEM, XPS and EPR spectroscopy. Subsequently, effects of key parameters viz., PMS dosage, catalyst dosage, pH and reaction temperature were evaluated on the degradation efficiency and simultaneously evaluated the PMS utilization efficiencies along with PMS consumption. Catalyst 0.6SCN exhibited the highest catalytic activity and maximum removal of acrylonitrile (96%) and acrylamide (81%) along with 86% PMS consumption were observed at optimum operatizing conditions. In addition, stability and recyclability of 0.6SCN catalyst were assessed and removal efficiency of acrylonitrile suppressed 6% and acrylamide suppressed 11% over the fourth cycle of experiments along with very low leaching of Cu and Ni observed. Furthermore, electron paramagnetic resonance (EPR) and quenching experimental studies reveal that in-situ generated both reactive species (SO 4 •– and • OH) were accountable for the removal of acrylonitrile and acrylamide synergistically in 0.6SCN/PMS system. Reaction pathways of acrylamide and acrylonitrile degradation were proposed based on the intermediate detected through GC–MS analysis and literature studies. Finally, the operating cost of treatment process was assessed 50.62$/m 3 of wastewater in 0.6SCN/PMS system.

Efficient Zr-doped FS–TiO2/SiO2 photocatalyst and its performance in acrylonitrile removal under simulated sunlight

The aim of this research is to develop an efficient photocatalyst for the degradation of acrylonitrile under simulated sunlight. In this work, Zr-doped FS–TiO2/SiO2 photocatalyst was reported for the degradation of acrylonitrile. Sol–gel method were used for the preparation of Zr-doped FS–TiO2/SiO2 with the molar ratio of Ti:Zr varied from 1:0.07. The prepared photocatalyst was calcined at 450 °C for 2 h. The characteristics of Zr-doped FS–TiO2/SiO2 were examined by X-ray diffraction (XRD), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and X-ray photoelectron spectroscopy (XPS). XRD results confirmed the presence of anatase phase of TiO2, and it also reveals that the Zr doping did not change the crystal phase of TiO2. The absorbance of Zr-doped FS–TiO2/SiO2 was significantly enhanced, as confirmed by the red shift in UV–Vis DRS spectra. Zr doping inhibits the recombination of electron–hole pairs and enhanced the photocatalytic activity. The UV–Vis DRS spectra show stronger absorption in Zr-doped FS–TiO2/SiO2 photocatalysts compared to FS–TiO2/SiO2. XPS analysis illustrated the presence of Zr4+, Ti3+, Ti4+, O2− and OH groups in Zr-doped FS–TiO2/SiO2. Then, the photocatalytic activity of the prepared photocatalyst was tested for the photocatalytic degradation of acrylonitrile under simulated sunlight. Zr doping, together with F and S would enhance the surface area and charge separation, making it serve as a more effectual photocatalyst than TiO2 and FS–TiO2/SiO2. The degradation ratio of acrylonitrile reached 79.2% within 6 min of simulated sunlight due to the doping effect of Zr into FS–TiO2/SiO2 photocatalyst. Zr doping could enhance the thermal stability of anatase phase of TiO2 and improve its surface properties.

Enhanced catalytic activity of series LaCuxFe1-xO3 (x = 0.2, 0.4, 0.6, 0.8) perovskite-like catalyst for the treatment of highly toxic ABS resin wastewater: Phytotoxicity study, parameter optimization and reaction pathways

In the present study, acrylonitrile butadiene styrene (ABS) resin wastewater was treated by series LaCuxFe1-xO3 (x = 0.2, 0.4, 0.6, 0.8) perovskite-like catalyst activated with peroxymonosulfate (PMS). The catalyst was synthesized by solgel method and further characterized by various techniques including i.e., XRD, FTIR, BET, FE-SEM with EDAX, TEM and XPS. Phytotoxicity study was performed to assess the toxicity of ABS resin wastewater on common agriculture crops viz., Vigna radiatus L. (Mung) and Hordeum vulgare L.(Barley). The effect of various parameters e.g., catalyst dosage (250−1050 mg/L), PMS dosage (1−5 mM), pH (2−10) and temperature (30−90 °C) were evaluated and optimize the parameters through central composite design (CCD) in response surface methodology (RSM). The maximum removal of acrylonitrile and TOC were observed 94.06 % and 66.70 %, respectively at optimum operating conditions obtained from RSM tools. The kinetic studies for the degradation of acrylonitrile and TOC was performed by two step pseudo first order kinetic model at various temperatures (30−90 °C). Catalyst reusability and chemical stability study were analyzed and degradation of acrylonitrile i.e., 94.06 %, 91.38 %, 88.42 % and 86.92 %; and TOC i.e., 66.70 %, 64.35 %, 61.59 % and 59.21 % were observed in first, second, third and fourth consecutive cycles. The proposed reaction pathways and PMS activation mechanism were investigated based on intermediate detected from GC–MS analysis and scavenger experimental study. Operating cost of treatment of ABS resin wastewater was estimated to be 75.60$/m3 wastewater.

Efficiently degradation of acrylonitrile from aqueous solution by La0.5Ce0.5MO3 (M = Fe, Cu and Co) perovskite-like catalyst: Optimization and reaction pathways

The present study focuses on catalytic degradation of carcinogenic and refractory organic compound (acrylonitrile) with La0.5Ce0.5MO3 (M = Fe, Cu and Co) perovskite-like catalysts synthesized by sol-gel method were examined by catalytic peroxidation process. Various analytical techniques, including XRD, FTIR, BET surface area, XPS, FE-SEM with EDAX and TEM were used for catalyst characterization. During catalytic peroxidation, influence of various operating parameters such as, catalyst dose (250–1250 mg/L), H2O2/ acrylonitrile (0.5–2.5), pH (2–10) and reaction temperature (30–90 °C) was studied and optimized through central composite design (CCD) in response surface methodology (RSM). Maximum acrylonitrile removal of 90.11% was observed at optimum operating conditions (i.e., LCFe catalyst dose 660 mg/L, H2O2/ acrylonitrile molar ratio 1.54, pH 5.4, reaction temperature 56.7 °C and reaction time 3 h). Two-step first order kinetics was performed at optimum operating conditions for the degradation of acrylonitrile at various temperatures and concentrations. To assess the economic viability of catalyst, reusability study was executed over four cycles of experiments at optimum operating conditions. The acrylonitrile removal was gradually dropped from 90.11% to 80.38%, 73.42% and 69.92%, respectively in second, third and fourth cycles. The proposed pathways of acrylonitrile degradation were suggested on the basis of intermediates identified by GC–MS analysis and reactive oxidant species (ROS) study. The operating cost of acrylonitrile treatment from aqueous solution was estimated to be 61.14 $/m3 wastewater by catalytic peroxidation process.

Efficient photocatalytic degradation of acrylonitrile by Sulfur-Bismuth co-doped F-TiO2/SiO2 nanopowder

In this study, a simple sol-gel method was applied for preparing effectual photocatalyst of S-Bi co-doped F-TiO2/SiO2 (S-Bi-F-TiO2/SiO2) nanopowder. Optimal preparation conditions were obtained by optimizing the calcination temperature and the ratio of S and Bi. The synthesized powder was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), brunauer-emmett-teller (BET), UV–Visible diffuse-reflectance spectroscopy (UV–Vis DRS), photoluminescence spectroscopy (PL) and ammonia adsorption and temperature-programmed desorption (NH3-TPD). The photocatalytic activity was evaluated by the degradation of acrylonitrile under simulated visible light irradiation. S-Bi-F-TiO2/SiO2 nanopowder possess excellent photocatalytic properties under visible light for the degradation of acrylonitrile, when the calcination temperature was 450 °C for 2 h and the ratio of S and Bi was 0.02: 0.007. The degradation efficiency of acrylonitrile reached to 81.9% within 6 min of visible light irradiation. Compared with F-TiO2/SiO2 sample, NH3-TPD and PL results revealed the higher photocatalytic activity for S-Bi-F-TiO2/SiO2, which is mainly due to the increase strength and number of surface acid site with S doping. The co-doping with S & Bi improved the separation of electron-hole pairs and enhanced the photocatalytic oxidizing species. The UV–Vis DRS showed stronger absorption in S-Bi co-doped F-TiO2/SiO2 catalyst as compared to F-TiO2/SiO2 catalyst. XPS results demonstrated the presence of various surface species viz. oxygen vacancies, Ti3+, Ti4+, O2− and OH group.

Effect of Tin Dioxide Modified F-TiO2/SiO2 Nano-Powder Catalysts on Photocatalytic Degradation of Acrylonitrile

In this study, tin dioxide (SnO2) modified F-TiO2/SiO2 catalysts (F-TiO2/SnO2/SiO2) was prepared by two steps method. The prepared powders were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Ernmett-Teller (BET), ultraviolet-visible absorption spectroscopy (UV-vis), photoluminescence spectroscopy (PL). The photocatalytic activities was evaluated by degradation ratio of acrylonitrile, which reached 74.0%, that was higher than that of F-TiO2/SiO2 catalysts 60.5 % after irradiation under simulated sunlight for 6 min. A series of characterization showed that the SnO2 modified photocatalysts had small crystal size, large specific surface area, and were easily dispersed uniformly in the reaction system. The photoluminescence (PL) spectra were also slightly weakened, implying that SnO2 modification well inhibited the recombination of electron hole pairs. A red shift of absorption edge occurred implying that the utilization of visible light was effective.

Understanding the influence of media geometry on the degradation of acrylonitrile: Experimental and CFD analysis

The media geometry design is a parameter that influences the efficiency of PCO device for indoor air treatment. However, there is little information in the literature to show how it impacts degradation efficiency. In this work, media geometry influence on the degradation of acrylonitrile is investigated experimentally and with numerical simulations. The experiments were conducted in a laboratory closed loop multi-pass reactor with the aim of comparing degradation efficiencies using plane and pleated media geometries. The experimental results showed a higher removal efficiency for the pleated media. Numerical simulations provided some information to better connect the increase in efficiency to the change in media geometry considering and modeling the media as a porous zone. The simulation results showed that pollutants had lower velocity in pleated media thus contact time was increased by 76%. Additionally, the more heterogeneous distribution of velocity and irradiance in the pleated media could counteract the influence of the contact time and possibly explain the lower than expected experimental results.

Catalytic peroxidation of acrylonitrile aqueous solution by Ni-doped CeO2 catalysts: characterization, kinetics and thermodynamics

Acrylonitrile is one of the major pollutants of acrylonitrile–butadiene–styrene resin industry wastewater present in high concentration. In the current study, the treatment of acrylonitrile from aqueous solution was performed by catalytic peroxidation using Ni-doped CeO2 catalysts. Various catalysts with different loadings of nickel were synthesized by co-precipitation method and further characterized by X-ray diffraction, Fourier transform infrared spectroscopy, liquid nitrogen adsorption–desorption technique, transmission electron microscopy, scanning electron microscopy with energy-dispersive X-ray, thermogravimetric analysis and X-ray photoelectron spectroscopy. The effects of various parameters such as catalyst dose, pH, nickel loading, H2O2/acrylonitrile molar ratio, initial concentration of acrylonitrile, temperature and reaction time on acrylonitrile removal were studied. Maximum acrylonitrile removal of 84.12% was observed at optimum operating conditions of pH = 6.5, catalyst dosage = 500 mg/L, nickel loading = 2.5 wt.%, stoichiometric molar ratio (H2O2/acrylonitrile) = 1, temperature = 298 K and reaction time = 3 h. Acrylonitrile degradation kinetics was investigated using power law model and non-competitive Langmuir–Hinshelwood model in which non-competitive Langmuir–Hinshelwood isotherm model better fitted for acrylonitrile degradation using Ni-doped CeO2 catalyst. Thermodynamic study of the parameters has also been presented.

Acrylonitrile degradation by whole cells of Corynebacterium sp. D5, isolated from polluted industrial waste

Acrylonitrile is a toxic organo-cyanide compound extensively used as solvents and in the manufacture of plastics, polymers, synthetic fibers, resin, dyestuffs, pharmaceuticals and vitamins. Because of its acute neurotoxicity, mutagenicity, carcinogenicity and teratogenicity, discharge of acrylonitrile contained wastewater can lead to serious environmental pollution if is not controlled. Microbial degradation has been considered as a way of removing highly toxic nitriles from industrial waste. In our studies, the biodegradation of acrylonitrile was demonstrated by using whole cells of Corynebacterum sp. D5 isolated from polluted industrial wastewater. Although the bacterium could not utilized the compound as a source of carbon, energy and nitrogen for its growth, Corynebacterium sp. D5 was capable to degrade acrylonitrile (CH2=CH-CN) into acrylamide (CH2=CH-CONH2) and acrylic acid (CH2=CH-OOH). The acrylonitrile degradation took place via a two-steps reaction invoving nitrile-hydratase and amidase. During the degradation, the highest nitril hydratase activity was 4.894 nmol.(min.mg) −1 with the optimum temperature and pH was 25°C and pH 7.0, while the highest amidase acivity was 1,315 nmol.(min.mg) −1, with the optimum temparature and pH was 50°C and pH 6.0, respectively. Besides on acetonitrile as inducer, Corynebacterium sp. D5 was also able to grow on various saturated low molecular weight of nitrile and amide compounds.

Influence of operating parameters on the single-pass photocatalytic removal efficiency of acrylonitrile

Photocatalytic oxidation (PCO) is an advanced air cleaning technology that is used as a means to improve air quality in indoor environments and could also potentially be used in hospital operating rooms (ORs). However, when it comes to the feasibility of using PCO to remove VOCs, most studies have been on those that are commonly found in indoor environments like homes and schools. There are little or no studies on other indoor environments like hospitals. Therefore in this work, acrylonitrile, one of the hazardous compounds found in surgical smoke (a source of pollution in the OR) was chosen as a representative compound to evaluate the performance of a photocatalytic system in an OR. The experiments were performed in a 420-L multi-pass laboratory reactor. The performance of the system was based on the influence that three operating parameters (air velocity, light intensity and initial concentration) would have on the single-pass removal efficiency (SPRE). A mathematical model was used to enable the calculation of the SPRE from the experimental degradation profile. The influence of the operating parameters on the degradation of acrylonitrile as well as the possible intermediates formed and mineralization rates are discussed.

Influence of environmental parameters on the photocatalytic oxidation efficiency of acrylonitrile and isoflurane; two operating room pollutants

In hospitals, operating rooms (ORs) are very demanding in terms of the indoor air quality (IAQ) and require systems that minimize the concentrations of pollutants (microorganisms, chemical and particulate matter). Air treatment devices that use photocatalytic oxidation (PCO) could potentially be used in the OR to improve IAQ. In this work, the fate of two OR pollutants acrylonitrile (chemical found in surgical smoke) and isoflurane (anesthetic gas) when they go through a PCO device was investigated. The experiments were conducted in a laboratory closed loop multi-pass reactor. A mathematical model was utilized to enable the calculation of one indicator (single-pass removal efficiency) for acrylonitrile and two indicators (induction period and single-pass removal efficiency) for isoflurane. The degradation efficiency was then accessed by studying the influence of environmental parameters on these indicators. The parameters that were studied are the relative humidity, presence of co-pollutants and presence of particles. The parameters were observed to have similar effects on the degradation of both compounds. Increasing relative humidity inhibited the degradation probably due to competitive adsorption. The presence of co-pollutants like nitrous oxide and acetic acid caused a possible competition for adsorption unto active sites thus decreased the degradation efficiency of acrylonitrile and isoflurane. The increase in the concentration of the co-pollutants enhances the competitive effect and further decreases the degradation efficiency of the target pollutants. Finally the presence of particles on the photocatalytic media could block active sites thereby inhibiting the degradation of acrylonitrile and isoflurane.

Highly energy-efficient removal of acrylonitrile by peroxi-coagulation with modified graphite felt cathode: Influence factors, possible mechanism

A highly energy-efficient peroxi-coagulation (PC) process was developed based on modified graphite felt, and the acrylonitrile removal efficiency was also comparatively studied by electro-Fenton (EF) and electrocoagulation (EC). The results showed that acrylonitrile was slowly and ineffectively removed by EC and EF, whereas by PC it was not only more rapid, but also effective at wide pH ranges of 3.0–9.0, which overcame the pH limitations for EC and EF. In addition, the electric energy consumption (EEC) of EF, EC and PC was 36.01, 14.43 and 3.08 kWh/kg respectively, suggesting PC was more economical. The influence of important operating factors such as pH, applied current and initial concentration were investigated for these three processes. The production of OH and transformation of iron ions were analyzed to explore the mechanisms of PC process. Compared to conventional treatment methods, PC was more cost-effective due to the combined action of OH as well as the coagulation with the formed Fe(OH)3 precipitate. Primary intermediates were identified by GC–MS analysis, and a possible pathway was proposed by the action of OH in EF and the hydrogenation in EC. This work demonstrated that PC is cost-effective and has potential for the degradation of acrylonitrile.

An effective method and pathways of acrylonitrile degradation to acrylic acid through an alkaline hydrothermal system

ABSTRACTDegradation of pollution for specific chemicals represents an optimal approach to high-strength wastewater treatment. One-pot selective conversion of acrylonitrile to acrylic acid in a hydrothermal system with NaOH as a catalyst was carried out. The influence factors were evaluated, including initial acrylonitrile concentration, reaction temperature, reaction time and amount of alkali. Experimental results showed that the highest yield of acrylic acid (55%) was obtained at the initial acrylonitrile concentration of 3 × 103 mg/L, 300°C for 90 s with 1.0 M NaOH. To determine the reaction path, intermediates analysis and calculation of carbon and nitrogen balance were carried out by means of HPLC, GC and TOC/TN methods. Two probable reaction pathways were proposed as follows: (1) Acrylonitrile was hydrolyzed into acrylamide, and acrylic acid was obtained via further hydrolysis. (2) Acrylonitrile was converted into 3-hydroxy-propionitrile via additive reaction, and this product was readily converted to 3-hydroxy-propionic acid through two steps of hydrolysis, followed by dehydration reaction to produce acrylic acid. This study offered not only an efficient method to transfer highly toxic pollutants into valuable chemical, but also a better understanding of hydrothermal alkali catalytic reaction.

A quantum chemical study on ˙Cl-initiated atmospheric degradation of acrylonitrile

Degradation of acrylonitrile (CH2CHCN) by reaction with atomic chlorine was studied using quantum chemical methods.

Characterization of nanoscale zero-valent iron supported on granular activated carbon and its application in removal of acrylonitrile from aqueous solution

In this study, nanoscale zero-valent iron supported on granular activated carbon (NZVI/GAC) was synthesized by liquid-phase reduction of Fe(II) and used to degrade acrylonitrile, to improve the effectiveness of GAC as a pre-treatment for biodegradation. The as-prepared composites were characterized by a scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). NZVI nanoparticles with an average size of 20–80 nm were uniformly dispersed on the surface of GAC, but mainly in the pores. The SBET and total pore volume of NZVI/GAC were 478.7 m2/g and 0.522 cm3/g, which is about half that of GAC. NZVI/GAC had a remarkable removal capacity for acrylonitrile which resulted from the combined effects of reduction, adsorption and micro-electrolysis by the Fe0/GAC system. The infrared spectra indicated that Fe0 and the Fe0/GAC micro-electrolysis system played a significant role in degradation of acrylonitrile. Increased biodegradability of acrylonitrile was achieved by pre-treatment with NZVI/GAC before biological treatment.

Photocatalytic decomposition of acrylonitrile with N–F codoped TiO2/SiO2 under simulant solar light irradiation

The solid acid catalyst, N–F codoped TiO2/SiO2 composite oxide was prepared by a sol–gel method using NH4F as nitrogen and fluorine source. The prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–Visible diffuse reflectance spectroscopy (UV–Vis), ammonia adsorption and temperature-programmed desorption (NH3-TPD), in situ Fourier transform infrared spectroscopy (FT-IR) and N2 physical adsorption isotherm. The photocatalytic activity of the catalyst for acrylonitrile degradation was investigated under simulant solar irradiation. The results showed that strong Lewis and Brønsted acid sites appear on the surface of the sample after N–F doping. Systematic investigation showed that the highest photocatalytic activity for acrylonitrile degradation was obtained for samples calcined at 450°C with molar ratio (NH4F to Ti) of 0.8. The degradation ratio of 71.5% was achieved with the prepared catalyst after 6-min irradiation, demonstrating the effectiveness of photocatalytic degradation of acrylonitrile with N–F codoped TiO2/SiO2 composite oxide. The photocatalyst is promising for application under solar light irradiation. Moreover, the intermediates generated after irradiation were verified by gas chromatography–mass spectrometry (GC–MS) analysis and UV–Vis spectroscopy to be simple organic acids with lower toxicity, and the degradation pathway was also proposed for acrylonitrile degradation with the prepared catalyst.

Silica supported [formula omitted]/TiO2 for photocatalytic decomposition of acrylonitrile under simulant solar light irradiation

The SO42-/TiO2/SiO2 solid acids were prepared by impregnation method. The prepared powders were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FT-IR), and UV spectrophotometer. The photocatalytic activities of the powders were investigated using acrylonitrile as a probe molecule. The results showed that sulfur was highly dispersed in TiO2 crystals in the form of SO42-. In situ IR and UV spectrophotometer showed that the higher photocatalytic activity of SO42-/TiO2/SiO2 solid acid was due to the increase of the surface Bronsted and Lewis acid sites. However, excess coverage of SO42- on TiO2/SiO2 surface decreased the photocatalytic activity due to inhibition of light absorption. The optimum synthesis conditions were calcination temperature at 450°C for 2h and 7.04wt.% SO42- content. The degradation ratio of acrylonitrile reached to 97% with 1.0g SO42-/TiO2/SiO2 solid acid for 30min irradiation, indicating the effectiveness of photocatalytic degradation of acrylonitrile using the prepared catalyst.