Breakthrough curves of oil adsorption on novel amorphous carbon thin film

Break oily water emulsion during petroleum enhancing production processes using green approach for the synthesis of SnCuO@FeO nanocomposite from microorganisms

The aim of this work was to synthesize a green nanoparticle SnCuO@FeO nanocomposite core-shell to break oily water emulsions during petroleum-enhancing production processes as an alternative to chemical and physical processes. In this study, eight bacterial isolates (MHB1-MHB8) have been isolated from tree leaves, giant reeds, and soil samples. The investigation involved testing bacterial isolates for their ability to make FeO nanoparticles and choosing the best producers. The selected isolate (MHB5) was identified by amplification and sequencing of the 16S rRNA gene as Bacillus paramycoides strain OQ878685. MHB5 produced the FeO nanoparticles with the smallest particle size (78.7 nm) using DLS. XRD, FTIR, and TEM were used to characterize the biosynthesized nanoparticles. The jar experiment used SnCuO@FeO with different ratios of Sn to CuO (1:1, 2:1, and 3:1) to study the effect of oil concentration, retention time, and temperature. The most effective performance was observed with a 1:1 ratio of Sn to CuO, achieving an 85% separation efficiency at a concentration of 5 mg/L, for a duration of 5 min, and at a temperature of 373 K. Analysis using kinetic models indicates that the adsorption process can be accurately described by both the pseudo-first-order and pseudo-second-order models. This suggests that the adsorption mechanism likely involves a combination of film diffusion and intraparticle diffusion. Regarding the adsorption isotherm, the Langmuir model provides a strong fit for the data, while the D-R model indicates that physical interactions primarily govern the adsorption mechanism. Thermodynamic analysis reveals a ∆H value of 18.62 kJ/mol, indicating an exothermic adsorption process. This suggests that the adsorption is a favorable process, as energy is released during the process. Finally, the synthesized green SnCuO@FeO nanocomposite has potential for use in advanced applications in the oil and gas industry to help the industry meet regulatory compliance, lower operation costs, reduce environmental impact, and enhance production efficiency.

Produced Water Treatment with Conventional Adsorbents and MOF as an Alternative: A Review

A large volume of produced water (PW) has been produced as a result of extensive industrialization and rising energy demands. PW comprises organic and inorganic pollutants, such as oil, heavy metals, aliphatic hydrocarbons, and radioactive materials. The increase in PW volume globally may result in irreversible environmental damage due to the pollutants' complex nature. Several conventional treatment methods, including physical, chemical, and biological methods, are available for produced water treatment that can reduce the environmental damages. Studies have shown that adsorption is a useful technique for PW treatment and may be more effective than conventional techniques. However, the application of adsorption when treating PW is not well recorded. In the current review, the removal efficiencies of adsorbents in PW treatment are critically analyzed. An overview is provided on the merits and demerits of the adsorption techniques, focusing on overall water composition, regulatory discharge limits, and the hazardous effects of the pollutants. Moreover, this review highlights a potential alternative to conventional technologies, namely, porous adsorbent materials known as metal-organic frameworks (MOFs), demonstrating their significance and efficiency in removing contaminants. This study suggests ways to overcome the existing limitations of conventional adsorbents, which include low surface area and issues with reuse and regeneration. Moreover, it is concluded that there is a need to develop highly porous, efficient, eco-friendly, cost-effective, mechanically stable, and sustainable MOF hybrids for produced water treatment.

Fabrication of Hybrid Materials Based on Waste Polyethylene/Porous Activated Metakaolinite Nanocomposite as an Efficient Membrane for Heavy Metal Desalination Processes

Hybrid nanostructure materials derived from activated metakaolinite are of growing importance due to their intriguing structural/functional properties and promising biomedical/environmental applications, especially designing desalination membranes. Herein, we report procedures to design and fabricate membranes based on waste polyethylene/porous activated-metakaolinite thin film nanocomposites (WPE/PAMK-TFN). It has been devoted to improving water desalination processes, where efficient removal of trace level (~250 ppm) of toxic heavy metals such as Cd(II), Pb(II), and Cu(II) ions from synthetic wastewater solutions was highly accomplished. Physicochemical techniques such as X-ray diffraction (XRD), surface analysis (BET), and Fourier transform infrared spectroscopy (FTIR) have been extensively employed to elucidate the structure/composition of the prepared nanomaterials. The effect of concentration (0–0.5 wt%) of porous activated-metakaolinite (PAMK) on water permeation was investigated. The results obtained revealed that 0.5 wt% of PAMK clay particles produced the highest dispersion, as evident by SEM images of the nanocomposite membranes. Significantly, the constructed membrane showed marked improvements in porosity, hydrophilicity, and hydraulic resistance. Moreover, elemental mapping studies have confirmed the intercalation of activated bentonite clay within the polymer matrix. The obtained results demonstrated that increased flux and rejection capability of membranes occurred at high clay dosage. In contrast, the low rejection capability was observed at either lower pH and higher initial feed concentrations. Ultimately, for 250 ppm of Cd(II), Pb(II), and Cu(II) ions, the constructed membranes showed maximum removal capability of 69.3%, 76.2%, and 82.5% of toxic cations, respectively.

Separation of BTX Fraction from Reservoir Brines by Sorption onto Hydrophobized Biomass in a Fixed-Bed-Column System

Oily brine from the gas and oil industries remains the most difficult wastewater to treat due to its complex chemical composition, which includes aromatic hydrocarbons. Even at low concentrations, the presence of BTX (benzene, toluene, xylenes) can be extremely harmful to aquatic ecosystems. Fixed-bed adsorption columns are recommended for oily water treatment due to their flexibility and easy operation. In this research, pine sawdust modified with polydimethysiloxane (PDMS) and hydrophobic nanosilica was applied as a sorbent in a filtration system. The surface modification of raw fiber allowed to change its morphology and increase the roughness of it. The Yoon–Nelson, Bohart–Adams, Clark, and Belter models were applied to simulate continuous biosorption. The Bohart–Adams model strongly correlated with the experimental data and described the whole dynamic behavior of the column. The effect of feed flow rate (10–50 mL/min) on breakthrough characteristics was determined. Both the breakthrough and saturation time decreased as the flow rate increased. This study indicated that hydrophobized pine sawdust is an effective low-cost potential biosorbent for the removal of BTX fraction from produced water in continuous column mode.

Scalable Top-to-Bottom Design on Low Tortuosity of Anisotropic Carbon Aerogels for Fast and Reusable Passive Capillary Absorption and Separation of Organic Leakages

Creation of sustainable, cost-effective, and scalable absorbents with ideal absorption properties is a worldwide challenge because many high-performance absorbents are still restricted in laboratory scope due to several critical defects (like complex and eco-unfriendly synthesis process, high cost, and difficulty in large-scale production). Herein, a facile and scalable top-to-bottom design is proposed to create a kind of novel anisotropic carbon aerogels with low tortuosity of stacked laminated structure, derived from the hierarchical cellular channels of balsa wood. By virtue of this unique structure and favorable oleophilicity, fast passive capillary absorption with low flow resistance is achieved (as demonstrated by the theoretical modeling). As a result, the anisotropic carbon aerogels have quite sensitive selectivity to separate organic pollutants from water, broad-spectrum and high absorption capacity for different organic liquids (13 277-31 597 mg g^-1), and superior recyclability (98.7% absorption capacity retention after five cycles). Combining these outstanding performances with a cheap preparation strategy as well as good environmental friendliness, this work provides a kind of potential scalable materials for efficient reusable absorption and separation of organic leakages.

Synthesis and applications of CaCO3/HPC core-shell composite subject to heavy metals adsorption processes

Core-shell particles are a class of materials from nanostructures that have received increased attention recently due to their interesting properties and wide range of applications in catalysis, biology, chemistry of materials and sensors. Simple and cost-effective one-pot synthesis route to directly prepare CaCO₃@highly porous carbon microsphere in a core–shell structure (denoted as CaCO₃/HPC) had been developed as a high-performance heavy metals sorbent. XRD (X-Ray Diffraction), SEM (scanning electron microscopy), Raman, FTIR (Fourier Transform Infrared Spectroscopy) and BET tools were used in structure characterization of the products. The adsorption properties of the products obtained were studied. From this study the adsorption performances of CaCO₃/HPCwere found to be optimal by comparing the maximum adsorption capacity of heavy metal ions (Pb (II) and Co(III)) with CaCO₃/HPC.The adsorption of CaCO₃/HPCtest to Pb(II) and Co(III), in particular Pb(II) had a good effect over a wide pH range (pH 2–7). The maximum adsorption capacitiesof CaCO₃/HPC for Pb (II) and Co(III) were 677.6 mg/g, and 308.5 mg/g, respectively, at pH = 6 (lead ion was 5.5) and 25 °C, and the adsorption rate was fast. The lead ions can be adsorbed almost entirely in 5 minutes and only 0.2 g/L was the best effective doseof adsorbent. The prepared and carefully testednanocomposites had been found to be of excellent performances in adsorption and in analytical regeneration. The adsorption processof Pb(II) and Co(III) through core shell of the preparednanocomposite adsorbent was found to be a second-order chemical adsorption and fit for Langmuir and Freundlich isotherms, in the form of amonomolecular and multi-layer heavy metal adsorptionprocesses. The (CaCO₃/HPC)-based sorbents (with and without) pelletization shows superior heavy metals adsorption performances compared to a CaCO₃-based sorbent.

Synthesis and application of ion-imprinted polymer for the determination of mercury II in water samples

In this study, an innovative analytical methodology capable of selectively identifying and quantifying mercury contamination by the association of solid-phase extraction using ion-imprinted polymers as a sorbent phase and differential pulse anodic stripping voltammetry is proposed. To this end, the ion-imprinted polymers were synthesized and characterized by infrared spectroscopy and atomic force microscopy. The sorption capacities and the selectivity of the ion-imprinted polymers were compared to the ones related to the non-imprinted ones. Next, the experimental parameters of this solid-phase extraction method (IIP-SPE) were evaluated univariately. The selectivity of this polymeric matrix against other cations (Cd II, Pb II, and Cu II) was also evaluated. Limits of detection (LOD) and quantification (LOQ) obtained for the here proposed methodology were 0.322 μg L^-1 and 1.08 μg L^-1, respectively. Also, the precision of 4.0% was achieved. The method was finally applied to three water samples from different sources: for the Piratininga and Itaipu Lagoon waters, Hg II concentrations were below the LOQ and for Vargem River waters a concentration equal to 1.35 ± 0.07 mg L^-1 was determined. These results were confirmed by recovery tests, resulting in a recovery of 96.2 ± 4.0%, and by comparison with flame atomic absorption spectrometry, resulting in statistical conformity between the two methods at 95% confidence level.

Effect of competing ions and causticization on the ammonia adsorption by a novel poly ligand exchanger (PLE) ammonia adsorption reagent

In this paper, a poly ligand exchanger, Cu(II)-loaded chelating resin named ammonia adsorption reagent (AMAR), bearing the functional group of weak iminodiacetate acid, was prepared to efficiently remove ammonia from solutions. Batch adsorption equilibrium experiments were conducted under a range of conditions. The effects of pH on the removal of ammonia by AMAR were investigated at 25 °C. The copper loaded on the resin forms a complex with NH₃ in solution under alkaline condition. The effect of alkaline dosage (AD) on the ammonia adsorption was investigated. The maximum breakthrough bed volumes were obtained when the AD was set as 0.75 mmol OH^-/mL. The higher AD did not guarantee the better ammonia removal efficiency due to the forming of Cu(OH)₂ precipitate between OH^- in solutions and Cu(II) on the resin. The effect of competing ions on the adsorption breakthrough curve of virgin AMAR and causticized AMAR was also investigated. The results demonstrated that the existence of competing ions had a negative impact on the adsorption capacity for both virgin AMAR and causticized AMAR. After causticization, the AMAR was more resistant to the competing ions comparing with virgin AMAR. The bivalent Ca²⁺ affects the ammonia adsorption more than does the monovalent Na⁺.