Chemical Engineering Journal
ISSN : 13858947
Current Publisher: Elsevier BV (10.1016)
Total articles ≅ 17,889
Google Scholar h5-index: 106
Latest articles in this journal
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.121
Abstract:Sulfachloropyridazine (SCP) is a broad-spectrum sulfonamide antibiotic and has been detected in cattle farming and fishpond water samples. This paper presents the kinetics and removal of SCP by ferrate(VI) (FeO42-, FeVI) in the acidic to basic pH range. The species-specific rate constant (k, M-1 s-1) of protonated FeVI species (HFeO4-) is higher than that of the FeO42- species. This describes the decrease in k with increase in pH. The identified organic oxidized products (OPs) of reaction between FeVI and SCP suggest an extrusion of SO2 from the sulfonamide group and hydroxylation of the aniline moiety of SCP. The peak areas of the OPs at different molar ratios of FeVI to SCP (2.0-15.0) and the formation of sulfate ion are used to give a plausible mechanism for the transformation of SCP to different OPs. In the proposed mechanisms, the major pathway involves a single-electron transfer that leads to FeV and a radical cation intermediate resulting in SO2 extrusion. A secondary minor pathway, which does not lead to SO2 extrusion, involves the hydroxylation of the aniline moiety of SCP, which likely occurs via an oxygen-atom transfer step. The sulfate ion was formed as a result of SO2 (or sulfite ion) oxidation by FeVI, which could also generate the FeV species. The generated FeV species also participate in the overall oxidation of SCP by FeVI. Biodegradation and toxicity tests of the OPs were performed. Treatment results in river waters demonstrated that more than 90% of SCP was removed by FeVI.
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.119
Abstract:Synergistic degradation of enrofloxacin (EFA) in water by pulsed discharge plasma (PDP) assisted with graphene-WO3 nanocomposites was investigated. The graphene-WO3 nanocomposites with different weight ratio of graphene were prepared by a hydrothermal method, which were characterized by various aspects, such as structure and morphology, chemical bonding state, optical property and electrochemical property. The results showed that graphene could be hybridized with WO3 nanoparticles successfully. Compared to the pure WO3, the specific surface area enhanced and the light absorption range extended in the graphene-WO3 nanocomposites. Moreover, the separation rate of electron–hole pairs accelerated apparently. The result of degradation performance showed that graphene-WO3 nanocomposites significant improved the removal efficiency and first-order kinetic constant of EFA in PDP system. Highest removal efficiency (99.1%) could be obtained with 60 min treatment in PDP system with 3% graphene-WO3 nanocomposite, which was 23.1% higher than that in the sole PDP system. Correspondingly, the synergistic factor could reach 2.82, suggesting that the synergistic effect could be established. In addition, the effect of various factors including catalyst dosage, peak voltage, air flow rate and initial solution concentration on EFA degradation was evaluated. The graphene-WO3 nanocomposite addition further decomposed O3 and improved the generation of ·OH and H2O2. The mineralization and three-dimensional fluorescence analysis verified that the EFA molecules could be destroyed and lead to the generation of intermediates. Subsequently, the degradation intermediates were identified by liquid chromatography-mass spectrometry (LC-MS) and ion chromatography (IC). Based on the above analysis, EFA degradation mechanism in the PDP system with graphene-WO3 nanocomposites was proposed finally.
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.113
Abstract:This study presents a simple method of titanium dioxide modification by carbon. Monosaccharide (fructose) was used as the carbon source. The pressure modification using fructose caused enhancement of antibacterial efficiency. It was found that prepared photocatalysts were capable of total Escherichia coli and Staphylococcus epidermidis inactivation under the UV-A and artificial solar light, which was attributed to the changes of the surface characteristics, i.e. zeta potential. The best results were observed for the TiO2-F-1%-100 photocatalyst, containing 0.51 wt% of carbon with less negative zeta potential (-18.08 mV). The two-stage photocatalytic mechanism of bacteria destruction by •OH radicals was found. Obtained data suggest that fructose-modified photocatalysts may be useful in the development of alternative water disinfectants.
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.111
Abstract:Heavy metals have raised an increasing number of pollution incidents and resulted in potent damages to aquatic ecosystems and human health. Thus, effective and efficient approaches to eliminate heavy metal ions are in urgent needs. Herein, novel hybrid nanoparticles have been prepared by a facile method using epichlorohydrin as a cross-linker between amino-functionalized magnetic nanoparticles and carboxymethylated lignin. Multiple characterization methods including XRD, FTIR, XPS, SEM, and TEM confirmed the formed nanostructures and the chemical features of the lignin-based hybrid nanoparticles. The as-synthesized hybrid nanoparticles exhibited high adsorption capacities of 150.33 and 70.69 mg/g for Pb2+ and Cu2+, respectively. More importantly, the adsorption equilibriums of Pb2+ and Cu2+ onto hybrid nanoparticles can be achieved within 30 seconds, which are among the fastest functional adsorbents for Pb2+ and Cu2+ removal as reported by now. The ultrafast adsorption is ascribed not only to the nanostructures, but also to the abundant active sites provided by the carboxymethylated lignin. The mechanism of removing Pb2+ and Cu2+ by hybrid nanoparticles could be mainly attributed to ion exchange and hydrogen bonding. The tailored nanostructured hybrid nanoparticles with exceptional adsorption effectiveness and efficiency are low-cost and eco-friendly, which potentially meets the cost-effective criteria for producing the water treatment adsorbents on a large scale.
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.102
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Chemical Engineering Journal, Volume 362; doi:10.1016/s1385-8947(19)30186-x
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.097
Abstract:Biochar (BC) exhibits a great potential as an adsorbent in decontamination of water. To improve the adsorption capabilities and impart the particular functionalities of BC, various methods (chemical modification, physical modification, impregnation with different materials, and magnetic modification) have been developed. As compared to surface modifications, BC-based composites provide various technical and environmental benefits because they require fewer chemicals, lesser energy, and confer enhanced removal capacity. Therefore, this review focuses on BC composites prepared by the combination of BC with different additives including metals, metal oxides, clay minerals, and carbonaceous materials, which greatly alter the physicochemical properties of BC and broaden its adsorption potential for a wide range of aquatic contaminants. Techniques for the preparation of BC composites, their adsorption potentials for a variety of inorganic and organic environmental contaminants, factors affecting BC properties and the adsorption process, and the mechanisms involved in adsorption are also discussed. Modification typically alters the surface properties and functionalities of BC composites including surface area, pore volume, pore size, surface charge, and surface functional groups. Hence, modification typically enhances the adsorption capacity of BC for most organic and inorganic compounds. Nevertheless, some modifications negatively affect the adsorption of certain contaminants because of various factors including obstruction of pores due to over coating and development of same charge as contaminant on surface of BC. However, the use of BC composites in environmental remediation is still in its infancy, and further research and development is needed to reach scalability and commercialization of the new technology.
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.099
Abstract:Amino group functionalized hydrophobic ionic liquid, 1-ethylamine hydrobromide-3-methylimidazolium hexafluorophosphate (ILPF6) ionic liquid, was employed as the functional monomer to fabricate a carbon-based hole-conductor-free perovskite solar cell with high performances. The photoactive perovskite layer was facilely acquired by one-step spin-coating the precursor solution on a TiO2/FTO electrode surface, and subsequently annealed at an initial annealing at 60 °C for 3 min followed by annealing at 100 °C for 10 min to crystallize. The perovskite precursor solution was prepared by mixing ILPF6 ionic liquid and methylammonium iodide with an equal molar ratio of PbI2. In the optimized conditions, the power conversion efficiency (PCE) was enhanced from 10.08% to 13.01% by doping ILPF6 into the perovskite crystal film. This study demonstrates the multifaceted functions of ILPF6 ionic liquid in improving the efficiency and stability of PSCs. First, ILPF6 can react with PbI2 to form perovskite and can also play a role of the controlling and crosslinking reagent to obtain large grain size and minimize defects. Secondly, ILPF6 improve the loading amount of perovskite crystals on the TiO2 film. Third, ILPF6 can promote the transport rate of the photogenerated carriers in the perovskite crystal layer. Lastly, ILPF6 ionic liquid with its high hydrophobicity creates a moisture barrier to improve the stability of PSCs effectively. The PSCs were stored under dark in a low relative humidity atmosphere (RH of 20%) at 25 °C without sealing. After 840 h, the PSC can maintain 94% of its initial PCE under the identical intensity illumination. This study demonstrates an excellent strategy to break through the bottleneck of the traditional PSCs and the enhanced effect of ionic liquid for carbon-based PSCs.
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.060
Abstract:Due to its strong exothermicity and strong reactant inhibition, the FTS is a great candidate for employing a cross-flow reactor, in which the reactants are distributed along the reactor. The desired temperature, which is 480-500 K on a Co catalyst, aimed to achieve reasonable conversion with reasonable selectivity, is achieved by cooling, either by using a diluent by inert or by using a heat exchanger. The main features of the CFR for generic kinetics like 1st order exothermic reaction, were analyzed and published by our group. Here we apply this design for FTS on a Co catalyst using a published kinetics based on a L-H mechanism coupled with an Anderson-Schultz-Flory kinetic model for high hydrocarbons to show the advantages gained - better activity and selectivity - since most of the reactor is operating at fixed conditions, unlike the PBR. The analysis follows several steps: (i) analysis of multiplicity of homogeneous states; (ii) analysis of the steady state spatial solution and plot of the domain of attraction of the active state; (iii) analysis of the full 1-D dynamic model, showing travelling-fronts or travelling–pulses, that may exit the system, as well as stationary-pulse solutions. In conclusion we note that the CFR offers many advantages at the expense of a more complex reactor structure: In the discussion we analyze the implications of the various parameters (mass- and heat-transfer) and the implications of the assumptions made in the model and conclude that the parameters are realistic.
Chemical Engineering Journal; doi:10.1016/j.cej.2019.04.013
Abstract:Self-sustained biorefinery model was designed with Azolla cultivation as major a feedstock for biobased products by integrating multiple bioprocesses such as acidogenesis, photosynthesis, hydrolysis, and pyrolysis. The cascading loop was initiated by acidogenesis of spent wash (distillery wastewater- DSW) in a semi pilot scale bioreactor for the production of biohydrogen and volatile fatty acids (VFA). Treated spent wash after acidogenesis (TSW) was used for Azolla pinnata cultivation which eventually showed considerable amount of nitrates and COD removal. A.pinnata biomass (AB) was harvested and analyzed for its biochemical composition which showed the presence of good amount of carbohydrate (237.8 mg/g) and protein (160 mg/g) along with 11% of lipids (composed of 22% omega fatty acids) thus making a good nutritional feed for livestock. AB after lipid extraction was subjected to mild acid-hydrolysis and the hydrolysate was used as substrate for acidogenesis to facilitate circular and closed loop of operation which resulted in biohydrogen and VFA production. The economics of this integration study performed using SuperPro Designer resulted in higher annual revenue that annual operating cost with the payback time of 1.55 years making the process economically profitable and sustainable. This study extends the scope of biobased platform with self-sustainability as core objective.