The removal of sulfur from petroleum products is an important step in the refining process. Several techniques have been developed to address the limitations of hydrodesulfurization, including ...adsorptive desulfurization. One of the requirements of the adsorptive desulfurization process is the use of efficient and cost-effective materials. In this work, activated carbon (AC) derived from waste rubber tires was loaded with cobalt and copper nanoparticles. The prepared materials were evaluated for their efficiency in batch and fixed-bed systems for the simultaneous adsorptive desulfurization of thiophene (T), benzothiophene (BT), dibenzothiophene (DBT), 5-methyl-1-benzothiophene (MBT), 4-methyldibenzothiophene (MDBT), and 4,6-dimethyldibenzothiophene (DMDBT). AC loaded with cobalt and copper (CoCu/AC) showed enhanced simultaneous adsorptive desulfurization of the sulfur compounds in the order of DBT > MDBT > DMDBT > MBT > BT > T. The adsorption experimental data showed the closest match with the pseudo-second-order kinetic. The intraparticle diffusion indicates that other mechanisms may be included in the adsorption process along with the intraparticle diffusion. Simultaneous adsorptive desulfurization in fixed bed models indicated the following trend in breakthroughs: DBT > MDBT > DMDBT > MBT > BT > T. A mechanism proposed via the π-complexation and the direct S-M interaction could justify the trend in adsorption capacity.
Nanomaterials (NMs) are gaining significance in technological applications due to their tunable chemical, physical, and mechanical properties and enhanced performance when compared with their bulkier ...counterparts. This review presents a summary of the general types of NMs and provides an overview of the various synthesis methods of nanoparticles (NPs) and their functionalization via covalent or noncovalent interactions using different methods. It highlights the techniques used for the characterization of NPs and discusses their physical and chemical properties. Due to their unique properties, NMs have several applications and have become part of our daily lives. As a result, nanotoxicity research is gaining attention since some NPs are not easily degraded by the environment. Thus, this review also highlights research efforts into the fate, behavior, and toxicity of different classes of NMs in the environment.
•Nanomaterials have fueled the development of new generation in several areas.•The review discusses the latest developments of these materials.•The review introduces the environmental impact and toxicity of nanomaterial.
Water pollution caused by numerous pollutants has become one of the critical problems globally. Different technologies and materials are used for the treatment of wastewater. There is a need for ...protocols and procedures that act as guidelines for researchers to develop and evaluate new adsorbent materials for wastewater treatment. This review takes a step toward developing organized protocols and procedures for the synthesis of nanomaterials, polymers, and green materials as adsorbents used for water purification. In the present review, protocols, and procedures for the synthesis of adsorbents, such as nanomaterials, waste-derived materials, and polymers are proposed Furthermore, protocols for evaluating these materials for water treatment are provided. The reported protocols and procedures will provide guidelines for researchers and industrial workers to develop and evaluate new materials for water treatment.
•Protocols for preparing various adsorbents for water treatment have been highlighted.•Protocols of testing adsorbents for water treatment have been designed.•Procedures of column testing for water treatment have been designed.•Protocols and Procedures provide guidelines for researchers to develop and evaluate new materials for water treatment.
Anthropogenic carbon dioxide (CO2) emissions have dramatically increased since the industrial revolution, building up in the atmosphere and causing global warming. Sustainable CO2 capture, ...utilization, and storage (CCUS) techniques are required, and materials and technologies for CO2 capture, conversion, and utilization are of interest. Different CCUS methods such as adsorption, absorption, biochemical, and membrane methods are being developed. Besides, there has been a good advancement in CO2 conversion into viable products, such as photoreduction of CO2 using sunlight into hydrocarbon fuels, including methane and methanol, which is a promising method to use CO2 as fuel feedstock using the advantages of solar energy. There are several methods and various materials used for CO2 conversion. Also, efficient nanostructured catalysts are used for CO2 photoreduction. This review discusses the sources of CO2 emission, the strategies for minimizing CO2 emissions, and CO2 sequestration. In addition, the review highlights the technologies for CO2 capture, separation, and storage. Two categories, non-conversion utilization (direct use) of CO2 and conversion of CO2 to chemicals and energy products, are used to classify different forms of CO2 utilization. Direct utilization of CO2 includes enhanced oil and gas recovery, welding, foaming, and propellants, and the use of supercritical CO2 as a solvent. The conversion of CO2 into chemicals and energy products via chemical processes and photosynthesis is a promising way to reduce CO2 emissions and generate more economically valuable chemicals. Different catalytic systems, such as inorganics, organics, biological, and hybrid systems, are provided. Lastly, a summary and perspectives on this emerging research field are presented.
Silica combined with 2 % multiwall carbon nanotubes (SiO
2
-CNT) was synthesized and characterized. Its sorption efficacy was investigated for the Hg(II) removal from an aqueous solution. The effect ...of pH on the percentage removal by the prepared material was examined in the range from 3 to 7. The adsorption kinetics were well fitted by using a pseudo-second-order model at various initial Hg(II) concentrations with
R
2
of >0.99. The experimental data were plotted using the interparticle diffusion model, which indicated that the interparticle diffusion is not the only rate-limiting step. The data is well described by the Freundlich isotherm equation. The activation energy (Ea) for adsorption was 12.7 kJ mol
−1
, indicating the process is to be physisorption. Consistent with an endothermic process, an increase in the temperature resulted in increasing mercury removal with a ∆H
o
of 13.3 kJ/mol and a ∆S
o
67.5 J/mol K. The experimental results demonstrate that the combining of silica and nanotubes is a promising alternative material, which can be used to remove the mercury from wastewaters.
Sulfur-containing compounds are the most abundant compounds in crude oil. Sulfur in liquid fuel oil leads to the emission of sulfur oxides and sulfate particulate matter which not only endangers ...health and community property but also reduces the life of the catalysts and engines due to corrosion. Various methods, with a high level of precision and sensitivity, have been developed to analyze sulfur-containing compounds. On the other side, the removal and characterization of sulfur-containing compounds in crude oils and petroleum products is of great importance, not only for the downstream refining process, control/optimization, and environmental compliance, but also for upstream geochemical studies for exploration and production. This review summarizes the analytical strategies and some of the most important and promising technologies for the removal of sulfur from oil.
The nature of multi-walled carbon nanotubes (MWCNTs) varies with the change in oxidation conditions. In this work, the effect of treatment temperatures on the acidity of MWCNTs was studied. Oxidation ...was performed by refluxing the MWCNTs in nitric acid or mixtures of sulfuric acid and nitric acid at different temperatures. After oxidative treatment, a quantitative characterization of o-MWCNTs has been performed using acid-base titrations which show that the number of surface acidic functional groups increased by increasing the treatment temperatures. Energy dispersive X-ray (EDX) measurements show that the oxygen content increased with increasing treatment temperatures. Fourier transform infrared absorption spectroscopy (FTIR) was used for qualitative characterization. It has been demonstrated that the acidity is a function of the type of oxidizing agent used and the treatment temperatures. Due to the importance in attachment strategies and functionalization, this study adds to the global discussion of the possibility of controlling the MWCNTs' surface chemistry which plays a crucial role in determining its reactivity.
The remarkable increase in the number of vehicles worldwide; and the lack of both technical and economical mechanisms of disposal make waste tires to be a serious source of pollution. One potential ...recycling process is pyrolysis followed by chemical activation process to produce porous activated carbons.
Many researchers have recently proved the capability of such carbons as adsorbents to remove various types of pollutants including organic and inorganic species. This review attempts to compile relevant knowledge about the production methods of carbon from waste rubber tires.
The effects of various process parameters including temperature and heating rate, on the pyrolysis stage; activation temperature and time, activation agent and activating gas are reviewed. This review highlights the use of waste-tires derived carbon to remove various types of pollutants like heavy metals, dye, pesticides and others from aqueous media.
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•A doubly effective solution for waste rubber tires is reviewed, where waste rubber tires are converted to porous carbon.•The tire-derived activated carbon was reviewed for its production methods.•The tire-derived activated carbon was reviewed for its characteristics and applications.
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•Graphene was modified with polyamide by interfacial polymerization.•The polyamide-graphene was evaluated for the removal of Sb(III).•The tests indicated high adsorption performance, ...high capacity and regeneration efficiency.
Graphene was modified with polyamide by using a facile interfacial polymerization method to obtain an effective composite. The produced polyamide-graphene (PAG) was characterized by Fourier transform infrared spectroscopy (FTIR), Scanning Electron microscopy (SEM) equipped with Energy-Dispersive X-ray spectroscopy (EDX), Thermogravimetric analyzer (TGA), and Brunauer–Emmett–Teller (BET) analysis methods. The adsorption efficiency of the adsorbent for the removal of Sb(III) was evaluated under the effects of concentration, temperature, contact time, medium pH, and re-usability. The results of the study showed very good adsorption performance and high regeneration efficiency. The Langmuir modeling results revealed that the synthesized PAG sorbent had a considerably high adsorption capacity (158.2mg/g) for Sb(III) ions from aqueous solution. The adsorption data fitted well into pseudo-second order model. The exothermic enthalpy change of −65.6kJ/mol and negative Gibbs free energy change assured the viability of the adsorption process under the considered temperature conditions. Moreover, by taking into account all results it was concluded that the PAG composite material leverages its cheap source and ease of regeneration in combination with its high and fast uptake capacities to offer a great promise for the remediation of Sb(III) ions from aqueous solutions.
The activated carbon (AC) was obtained from waste scrap tires and modified by bimetallic Fe and Ce nanoparticles in order to combine both the high surface area and the active sites for enhanced ...adsorption of the dye. The produced nanocomposite was used as a novel cost-effective magnetic in rhodamine B (RhB) removal from aqueous solutions. The FT-IR, SEM, EDX, TEM, and surface area analysis methods were implemented to characterize the morphological, chemical, thermal and surface properties of the developed adsorbent. The optimum batch experimental conditions were found under the response surface methodology. The adsorption equilibrium data were well fitted by the Langmuir isotherm model. The adsorption capacity was 324.6 mg g−1. The kinetic and thermodynamics studies were also carried out to understand the adsorption mechanism. The study indicated that RhB adsorption by the AC/Fe/Ce magnetic adsorbent has an endothermic character and followed the pseudo-second-order kinetics model. By using ethanol solution, RhB was desorbed at high efficiency and the prepared material could be recycled for up to ten cycles. Thus, the magnetic nanocomposite is an effective and promising adsorbent for the cleaning treatment of RhB ions from wastewater by a large scale designed adsorption system.
•Magnetic activated carbon was modified with cerium oxide nanoparticles•The composite showed high efficiency for dye sorption from aqueous solution•The composite showed thermal stability, excellent recovery and reusability
