Development of Sustainable Nanosorbcats Based Technology for Hydrocarbons and Organic Pollutants Recovery from Industrial Wastewater

The worldwide shortage of fresh water and the huge competing demands from a variety of users stimulate an urgent need for finding innovative wastewater treatment processes. For instance, oil sand process-affected waters pose a critical energy issue and an environmental alert since these effluents are toxic to many aquatic and non-aquatic living organisms. In addition, some of these pollutants are non-biodegradable and, thus they will exist for a long time in the environment, which may cause a real challenge to the conventional wastewater treatment processes. Accordingly, economically viable and environmentally sound techniques are needed. The application of nanoparticle technology as adsorbents and catalysts (nanosorbcats), whether as a standalone or as an enabling technology, in cleaning up wastewater has recently received great attention. This is because of the unique chemical and physical properties of nanoparticles in comparison with their counterparts, which make them superior to the conventional adsorbent/catalysts. Hence, in the present study, the employment of newly in-house prepared silica-embedded nanosorbcats functionalized with active species of NiO and MgO for cleaning up produced water was investigated. A facile co-precipitation synthesis route was used to prepare those nanosorbcats, which were characterized by different characterization techniques like XRD, BET, HRTEM, CO2-TPD, and IR spectroscopy. The prepared nanosorbcats were then employed for the adsorptive removal of cationic, anionic, and organic acid model molecules. Computational modeling, DFT calculations, and MD simulations of the interaction between the model molecules and the surfaces of prepared nanoparticles were carried out to get more mechanistic insights into their adsorptive behaviors. Eventually, these nanosorbcats were successfully used to treat real SAGD produced waters within an experimental scheme including three processes, namely; oxy-cracking, packed-bed adsorption, and catalytic steam gasification

Thermogravimetric kinetics study of scrap tires pyrolysis using silica embedded with NiO and/or MgO nanocataly

In this study, a set of three new silica-based embedded with NiO and/or MgO nanocatalysts (SBNs) have been prepared and tested for the pyrolysis of scrap tires (STs). The intent is to identify and optimize the best nanocatalyst that decreases the operating temperature and speeds up the pyrolysis reaction rate. The influence of the three prepared SBNs nanocatalysts on STs was scrutinized using thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The kinetic triplets were estimated utilizing the isoconversional method of the Ozawa–Flynn–Wall (OFW) corrected model. Experimental TGA and FT-IR results showed a thermal decomposition of all volatile organic additives alongside the polyvinyl compounds at a lower temperature in the presence of these SBNs. However, a competitive decomposition behavior appeared for each SBN nanocatalysts. The kinetic triplets’ findings showed different effective activation energy trends at two different conversion regions (low and high conversions), suggesting different reaction mechanisms confirmed by the reaction kinetic models. Interestingly, NiO-MgO-SBNs showed the highest reaction rate for this thermo-pyrolysis of STs, which could be because of synergetic interaction between NiO and MgO nanoparticles. Moreover, the results of the change in Gibbs free energy of activation (ΔG‡) indicated the promising catalytic activity for those SBNs by promoting the spontaneity of pyrolysis reaction. These proof-of-concept findings could promote the futuristic use of NiO-MgO-SBNs at the industrial level toward sustainable ST pyrolysis.The authors thankfully acknowledge Deanship of Scientific Research in An-Najah National University, Nablus, Palestine for providing financial support to this study via Project Number (ANNU-1819-Sc008). The technical assistance provided by Mr. Nafith Dwikat and by the faculty of Science at An-Najah National University (ANNU), Nablus, Palestine is also highly appreciated.Scopu

Photodegradation of ibuprofen using CeO2 nanostructured materials: Reaction kinetics, modeling, and thermodynamics

International audienceIbuprofen is one the most used non-steroidal anti-inflammatory drug, which is considered an emerging pollutant that may contaminate surface and underground water. Photodegradation using nanomaterials is one of the most sustainable and cheap technologies that can be used in water purification. In this study, the photodegradation efficiency of in-house prepared ceria (CeO2) nanostructured materials towards ibuprofen was assessed under UV irradiation. CeO2 nanoparticles (NPs) were prepared through wet-chemical synthesis and characterized by several techniques. The photodegradation activity of the synthesized CeO2-NPs was compared to the commercial Aeroxide TiO2-P25. Small crystalline CeO2-NPs were obtained with about 15 nm particle size, band-gap of 3.1 eVwith irregular morphology. The surface area of CeO2-NPs was estimated to be 76 ± 5 m2/g. Dynamic light scattering analysis revealed that these nanoparticles have a strong tendency to self-aggregate and to form clusters in aqueous suspension. The results showed a slightly better performance of Aeroxide TiO2-P25 compared to CeO2-NPs. On the other hand, five reusability tests confirmed the stability of CeO2-NPs in the reaction conditions,without any significant effect on their photodegradation activity. The goodness of the kinetic modeling of the experimental data was proven through the estimated kinetic parameters, together with the statistical information. The temperature effect confirmed that the higher the temperature, the greater the dissociation rate. Thus, there is a direct relationship between temperature, reaction rate, and the activation energy for each reaction.Furthermore, the thermodynamic parameters, namely: changes in Gibbs free energy (ΔG◦), enthalpy (ΔH◦), and entropy (ΔS◦) have been reported revealing the efficient photodegradation performance of CeO2-NP

Competitive adsorption of Alizarin Red S and Bromocresol Green from aqueous solutions using brookite TiO2 nanoparticles: experimental and molecular dynamics simulation

In this work, the effective adsorption and the subsequent photodegradation activity, of TiO2 brookite nanoparticles, for the removal of anionic dyes, namely, Alizarin Red S (ARS) and Bromocresol Green (BCG) were studied. Batch adsorption experiments were conducted to investigate the effect of both dyes' concentration, contact time, and temperature. Photodegradation experiments for the adsorbed dyes were achieved using ultraviolet light illumination (6 W, λ = 365 nm). The single adsorption isotherms were fitted to the Sips model. The binary adsorption isotherms were fitted using the Extended-Sips model. The results of adsorption isotherms showed that the estimated maximum adsorption uptakes in the binary system were around 140 mg g-1 and 45.5 mg g-1 for ARS and BCG, respectively. In terms of adsorption kinetics, the uptake toward ARS was faster than BCG molecules in which the equilibrium was obtained in 7 min for ARS, while it took 180 min for BCG. Moreover, the thermodynamics results showed that the adsorption process was spontaneous for both anionic dyes. All these macroscopic competitive adsorption results indicate high selectivity toward ARS molecules in the presence of BCG molecules. Additionally, the TiO2 nanoparticles were successfully regenerated using UV irradiation. Moreover, molecular dynamics computational modeling was performed to understand the molecules' optimum coordination, TiO2 geometry, adsorption selectivity, and binary solution adsorption energies. The simulation energies distribution exhibits lower adsorption energies for ARS in the range from - 628 to - 1046 [Formula: see text] for both single and binary systems. In addition to that, the water adsorption energy was found to be between - 42 and - 209 [Formula: see text]