Alkyl Polyglucoside Research Articles

Natural surfactant used as an additive in the homogenate-ultrasound-synergistic extraction of regaloside A and polysaccharides from Lilium lancifolium bulbs using Doehlert matrix design

In this study, 10 different natural surfactants were compared as additives for the simultaneous extraction of lipophilic regaloside A and water-soluble polysaccharides from tiger lily ( Lilium lancifolium Thunb.) bulbs by homogenate-ultrasound-synergistic extraction. Four significant factors that affect the yields of regaloside A and polysaccharides, including homogenate speed, ultrasound irradiation power, reaction temperature and ultrasound irradiation time, were screened by single-factor experiments and Plackett-Burman design and then optimized using Doehlert matrix design combined with a desirability function. The optimal extraction process conditions were obtained as follows: APG06 ( n -hexyl glucoside) surfactant concentration of 0.6%, homogenate speed of 20000 r/min, homogenate time of 6 min, liquid solid ratio of 20 mL/g, ultrasound irradiation power of 300 W, ultrasound irradiation time of 52 min, reaction temperature of 62.8 °C, and buffer and cavitation times of 1.5 s and 2.0 s, respectively. Under the optimal extraction conditions, regaloside A and polysaccharides yields of 2.797 ± 0.084 mg/g and 0.493 ± 0.016 g/g are obtained with relative standard deviations of 3.00% and 3.50%, respectively. The results of the method validation and comparison with the conventional method show that homogenate-ultrasound-synergistic extraction with APG06 as an additive is a green, efficient and energy-saving extraction method. Compared with the traditional extraction method, HUSE with APG06 as an additive is an effective method to extract regaloside A and polysaccharides from L. lancifolium bulbs. This study provides a reference for the development of green low carbon natural product extraction process. • Use homogenate-ultrasound-synergistic extraction of regaloside A and polysaccharides. • Alkyl polyglucoside was first added to extract phenolic acid glycerides (regaloside A). • 0.6% n -hexyl glucoside was chosen as the extraction additive. • Use combination of Plackett-Burman design and Doehlert matrix design. • Alkyl polyglucoside has obvious advantages on yield and safety compared with ethanol.

Correction to: A New Alkyl Polyglycoside from Ardisia crispa

Correction to: A New Alkyl Polyglycoside from Ardisia crispa

Interfacial and rheological properties of long-lived foams stabilized by rice proteins complexed to transition metal ions in the presence of alkyl polyglycoside

HypothesisTransition-metal coordination complexes are hopeful to make advanced structural materials, since the metal-coordination bonds, unlike typical covalent bonds, can regenerate after rupture, allowing for dynamic, tunable, and reversible mechanical characteristics. Integration of metal-coordinate crosslinking in foam material has rarely been reported. ExperimentsWe developed the hydrolyzed rice proteins (HRP) as the building block for amphiphilic transition-metal coordination complexes that could be used to make long-lived foams with high yield stress. Surface properties of the foaming solution were determined using equilibrium and dynamic tensiometers. Structural information of aggregates in the foaming solution was detected by small-angle X-ray scattering (SAXS) and Cryo-Tem. Visualization of liquid flow in the interfacial liquid film was studied by the reflective optical interference technique. Rheological response of liquid foam was characterized by a rheometer with amplitude-sweep and frequency-sweep modes. FindingsIn the presence of transition metal ions, HRP formed a mechanically strong rigid film. In the absence of transition metal ions or the addition of alkyl polyglycoside (APG), HRP was desorbed to produce a mobile film with a detergent state. The two interfacial states could be actively switched based on facile changes in bulk solution composition (metal ions or alkyl glycoside or chelating agent), and the switching between the two states led to the formation of extremely stable foam with high yield stress or the collapse of foam with a significant decrease in yield limit. The transition-metal coordination complexes adsorbed on the surface of the liquid film could increase the elastic modulus of liquid foam by more than an order of magnitude without increasing the viscosity of the foaming solution. We further revealed the origin of foam stability/instability and used other well-characterized proteins to prepare transition-metal coordination complexes to make long-lived foams. The cases described in this work illustrate the universal nature of the strategy, which in principle can be extended to many types of protein.

Machine Learning to Predict the Interfacial Behavior of Pesticide Droplets on Hydrophobic Surfaces for Minimizing Environmental Risk

Achieving accurate and efficient target deposition of pesticide droplets is the principal factor in minimizing environmental risk. For hydrophobic surfaces, adding tank-mix adjuvants containing surfactants to modulate interfacial behavior is warranted, which lacks common laws to guide practical applications directly. Machine learning is developing rapidly and makes many data-based decisions in various industrial processes. Hence, according to machine learning-based analysis of fundamental physical quantities, proposing quantitative sustainability metrics to improve interface behavior is essential. Comparing the interfacial behavior of five adjuvants, the common denominator is that droplets in the Wenzel state with higher adhesion tension and lower contact angles can generate the pinning force that causes energy dissipation, reduces pesticide losses, and weakens environmental pollution. Simultaneously, the interfacial behavior of pesticide droplets including adjuvants on citrus leaves is verified, while the phytotoxicity experiment under high temperature and the laboratory bioassay are carried out. The results show that the eco-friendly alkyl polyglycoside (APG) as the glycosidic surfactant has nontarget biosafety and better mite control, which can be exploited as a commercial tank-mix adjuvant for promotion. This study provides a new insight into guiding adjuvants added to pesticides on account of quantitative sustainability metrics, which has important implications for food safety and agricultural green development.

Experimental study on alleviating water-blocking effect and promoting coal gas desorption by gas wettability alteration

To alleviate the water-blocking effect in the hydraulic fracturing process and promote coal seam gas extraction, the influence of gas wettability alteration on the water-blocking effect and gas desorption was investigated. First, according to the contact angle, infrared spectrum, and surface energy measurement experiments, 3.5% polyacrylamide (PAM) was selected as the gas wettability alteration agent and used to treat the coal samples. After treatment with PAM, the hydroxyl and surface energy of the coal decreased, which altered the gas wettability. Second, the water injection desorption experiment results show that both 4% alkyl polyglucoside (APG) and 3.5% PAM solution can alleviate the water-blocking effect and promote coal gas desorption during water injection. The same experiment was performed by varying the gas pressure. When the gas pressure exceeds 3.25 MPa, APG inhibits gas desorption, indicating that it is unsuitable for alleviating the water-blocking effect. Furthermore, the mechanism by which gas wettability alteration relieves the water-blocking effect was analyzed from macroscopic and microscopic perspectives. Macroscopically, PAM had a high removal rate of the liquid-phase retention effect in coal and can hardly be retained in coal. Microscopically, after gas wettability alteration, the number of hydrophilic functional groups on the surface of coal decreased. The above results in the system changing from hydrophilic to hydrophobic, and correspondingly, the capillary pressure in pores or fractures of coal changes from resistance to a driving force. Therefore, compared with the original coal sample, the water in the coal is more likely to flow back, which alternates the water-blocking effect and promotes gas desorption. This study provided a laboratory prediction method for verifying the effects of gas wettability alteration agents on coal gas extraction.

Experimental evaluation of non-ionic mixed surfactant formulations at high-temperature and high-salinity conditions

Non-ionic alkyl polyglucoside (APG) surfactants have been considered as eco-friendly, nontoxic and biodegradable surfactants. This study investigated the feasibility and advantages of new formulations for mixed surfactants consisting of a commerical APG product and one of the following alkyl amines (AAs) – dodecylamine (C12A), tetradecylamine (C14A), hexadecylamine (C16A), and octadecylamine (C18A) for improved oil production applications in carbonate reservoirs under high-temperature and high-salinity (HTHS) conditions. The physicochemical properties including compatibility, surface tension, interfacial tension (IFT), static adsorption, wettability alteration of the solutions comprising APG and various AA under HTHS conditions were evaluated. The self-assemble behavior of molecules between APG and C12A was characterized based on the Scanning Electron Microscopy (SEM) analysis. The formulations with an ultra-low IFT were introduced and the mechanisms resulting in such ultra-low IFT were further studied and discussed. The yielded APG/AA formulation was injected as the chemical flooding agent into a micromodel to investigate the efficiency of oil displacement. Commercial APG products exhibited excellent compatibility with the simulated injection water at reservoir temperature. After mixed with AA, the APG solution became hazy or phase separated above a critical concentration (Ccrit) of AA. Ccrit was found to decrease with an increase of the hydrocarbon chain, suggesting that more APG surfactants are required to solubilize the AA with longer alkyl hydrocarbon chain. In the presence of AA, the critical micelle concentration (CMC) of APG surfactant significantly reduced due to the formation of a compact micellar structure. APG yielded a low IFT at 90 °C and a concentration of 2 g/L in the order of 10−2 mN/m, while an ultra-low IFT in the order of 10−3 mN/m was obtained upon addition of a small amount (0.3–0.5 g/L) of C12A. SEM images and proposed IFT reduction mechanisms indicated that APG and C12A synergistically generated a more compact structure via hydrophobic interaction between the hydrophobic moieties and hydrogen bonding between the hydrophilic parts of the chemicals comparing the aggregated structure formed by APG alone, such effect could eventually lead to a decrease in IFT between oil and water. The amounts of chemical adsorption and contact angle of an oil droplet on carbonate cores were not affected upon addition of AA. The micromodel test showed that the produced oil by injection of the designed APG/AA formulations was further enhanced after water flooding. Among the formulations, APG/C12A flooding resulted in a highest effectiveness on oil displacement with a cumulative oil production of 78.7% at the end of injections. To sum up, new APG/AA-based formulations were designed with an ultra-low IFT resulting from a much compact amphiphilic structure along oil-water interface. This study shows a great potential of APG surfactant and the related formulations in improving oil production for HTHS carbonate reservoirs.

Efficient and simple method for the quantification of alkyl polyglycosides by hydrolysis and photometric determination of reducing sugars

Alkyl polyglycosides (APG) are important biodegradable surfactants for many applications. The lack of a chromophoric group and the mixture of stereoisomers and oligomers make the quantification by merely chromatic separation difficult. A simple and efficient quantification assay was developed based on the acid hydrolysis of alkyl polyglycoside and subsequent quantification of the hydrolytically cleaved glucose using the neocuproine assay. Complete hydrolysis of alkyl polyglycoside is achieved with 16 wt% sulfuric acid at 100 °C after 30 min and the separation of fatty alcohol and clouding of the reaction mixture is prevented by adding 1,2-propylene-glycol. Hydrolytically cleaved sugars reduce the Cu (II) -neocuproine complex, leading to a color shift which permits the spectrophotometric quantification at 452 nm. A linear correlation between the absorbance of reduced Cu (II) -neocuproine complex and glucose or alkyl polyglycoside concentration is observed up to an analyte concentration of 25 mg/L. Statistical analysis according to one-tailled T-test (S’ 95%), has shown that the lower detection limit for alkyl polyglycosides is 2.97 mg/L and the limit of quantification 8.24 mg/L, respectively. Apart from the simple execution, the assay is reliable and can be utilized both as scientific technique to quantify APG as well as for process and quality control in the industry.

Alkyl polyglucoside-based supramolecular solvent formation in liquid-phase microextraction

The phenomenon of alkyl polyglucoside-based supramolecular solvent formation in the presence of alkyl carboxylic acid acted as coacervation agent was described for the first time. Various alkyl polyglucosides and carboxylic acids were studied as the amphiphiles and coacervation agents, respectively. A possible mechanism of the new supramolecular solvent formation was presented. The physico-chemical properties of the developed alkyl polyglucoside-based supramolecular solvents were investigated. The green liquid-phase microextraction approach with the use of alkyl polyglucoside-based supramolecular solvent was developed and applied to epinephrine (hormone and biomarker for the diagnosis of adrenal glands neoplastic diseases) separation and preconcentration from human urine samples prior to its chromatographic determination. Caprylyl/capryl glucoside was found to be the most effective supramolecular solvent precursor for microextraction of the epinephrine (extraction recovery 95%). The microliter amount of the heptanoic acid was required to induce coacervation process and phase separation. The reduced fluidity of alkyl polyglucoside-based supramolecular solvent under cooling was used to simplify the collection of the extract phase by decantation. The green supramolecular solvent obtained was less viscous then known nonionic surfactant-based solvents and as result more compatible with the high-performance liquid chromatography with fluorometric detection.

Influence of electrolytes on the structural and viscosity properties of mixed anionic–nonionic–zwitterionic surfactants in detergent formulations

AbstractCleaning products have a global market of around $33 billion in 2020 and play an essential role in daily life, providing consumers with important public health benefits. Surfactants are the main ingredients of cleaning products and they can effectively remove dirt, germs, and other contaminants from surfaces. Understanding the role of each surfactant class in a detergent formulation and their interaction with NaCl is of utmost importance for formulating efficient and sustainable cleaning products. This paper describes the study of ternary surfactant systems consisting of surfactants (sodium lauryl ether sulfate, alkyl polyglycoside, or betaine, three of the most commonly used surfactants in detergent formulations), water, and NaCl. The effects of concentration on critical micelle concentration, aggregate size, and rheological behavior were evaluated by dynamic light scattering and rheology techniques.

Preparation and characterization of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/gelatin composite nanofibrous

In order to compound gelatin (GEL) with poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3,4HB)) to improve the hydrophilicity and biocompatibility, a simple and convenient method for preparing P(3,4HB)/GEL composite nanofibrous (P/G-CNF) was proposed. Alkyl Polyglycoside (APG) was used as an emulsifier to prepare a stable P(3,4HB)/GEL composite solution, and novel P/G-CNF was prepared by electrospinning. The intermolecular interaction, micromorphology and porosity, crystallization and mechanical properties, hydrophilicity and cytocompatibility of P/G-CNF were characterized. The results reveal that P(3,4HB), APG and GEL form many hydrogen bonds. When the m(P(3,4HB):GEL) is 10:2, the as-prepared nanofibrous exhibit the best micromorphology with a diameter and porosity of 604 nm and 68.33%. With the increasing GEL content, the crystallization and mechanical properties of P(3,4HB)/GEL composite nanofibrous scaffold (P/G-CNS) are further enhanced and decline after reaching the maximum. The hydrophilicity of P/G-CNS is significantly improved by introducing GEL. The cell proliferation rate of P/G-CNS is higher than 100%, of which the cytotoxicity grade is 0, indicating that it is non-cytotoxic. The P/G-CNS has excellent cytocompatibility and provides better cell attachment, growth and proliferation, showing promising application prospects for tissue regeneration and biomedical materials.

Environmental impact assessment of nanofluids containing mixtures of surfactants and silica nanoparticles

Due to widespread use of nanoparticles in surfactant-based formulations, their release into the environment and wastewater is unavoidable and toxic for biota and/or wastewater treatment processes. Because of concerns over the environmental impacts of nanofluids, studies of the fate and environmental impacts, hazards, and toxicities of nanoparticles are beginning. However, interactions between nanoparticles and surfactants and the biodegradability of these mixtures have been little studied until now. In this work, the environmental impacts of nanofluids containing mixtures of surfactants and silica nanoparticles were valuated. The systems studied were hydrophilic silica nanoparticles (sizes 7 and 12 nm), a nonionic surfactant (alkyl polyglucoside), an anionic surfactant (ether carboxylic acid), and mixtures of them. The ultimate aerobic biodegradation and the interfacial and adsorption properties of surfactants, nanoparticles, and mixtures during biodegradation were also evaluated. Ultimate biodegradation was studied below and above the CMCs of the individual surfactants. The interfacial and adsorption properties of surfactant solutions containing nanoparticles were influenced by the addition of silica particles. It was determined that silica nanoparticles reduced the capability of the nonionic surfactant alkyl polyglucoside to decrease the surface tension. Thus, silica NPs promoted a considerable increase in the surfactant CMC, whereas the effect was opposite in the case of the anionic surfactant ether carboxylic acid. Increasing concentrations of surfactant and nanoparticles in the test medium caused decreases in the maximum levels of mineralization reached for both types of surfactants. The presence of silica nanoparticles in the medium reduced the biodegradability of binary mixtures containing nonionic and anionic surfactants, and this effect was more pronounced for larger nanoparticles. These results could be useful in modelling the behaviour of nanofluids in aquatic environments and in selecting appropriate nanofluids containing nanoparticles and surfactants with low environmental impact.Graphical abstract

A New Alkyl Polyglycoside from Ardisia crispa

A New Alkyl Polyglycoside from Ardisia crispa

PHASE BEHAVIOR STUDIES OF ALPHA OLEFIN SULFONATE (AOS), LAURYL GLUCOSIDE, AND DECANE IN CREATING WINSOR TYPE-III MICROEMULSION

One of the methods to increase the oil recovery is by signifcantly increase the capillary number. This can be achieved by reducing the interfacial tension (IFT) between the oil and the water in the reservoir to an ultra-low value. There are many studies conducted that proved the ability of Winsor Type-III microemulsion to reduce the IFT to an ultra-low value. Winsor Type-III microemulsion can be created by mixing surfactant, cosurfactant or cosolvent, brine, and oil. However, there has not been any research related to microemulsion creation conducted on alpha olefn sulfonate, AOS and alkyl polyglucoside, and, APG surfactant mixture. Commonly, alcohol as a cosolvent will be added to the surfactant system to enhance the surfactant ability in creating Winsor Type-III microemulsion, but in this project, alcohol will be replaced with an environmental friendly nonionic surfactant, lauryl glucoside. In this project, the phase behavior study of a novel ‘green’ surfactant mixture was conducted to evaluate the potential of the surfactant in creating Winsor-Type III microemulsion and determine the optimum formulations to create a stable Winsor Type-III microemulsion. The phase behavior studies were conducted in three stages which are the optimization of salinity, surfactant concentration, and cosurfactant concentration. Phase diagrams were constructed to properly analyze the phase behavior of the components in a wide range of decane volumes. From the phase behavior studies conducted, it can be concluded that the optimum formulation is 3 wt% salinity, 1 wt% AOS, and 3 wt% lauryl glucoside. Lauryl glucoside addition in the mixture could alter the HLB value of the surfactant mixture hence increasing its potential in creating Winsor Type-III microemulsion.
 Keywords: Enhanced Oil Recovery, surfactant, alkyl polyglucoside

Removal of uranium by APG/TAS antifreeze foam detergent with high foaming property

The environmentally friendly antifreeze foam detergent was synthesized from the biomass-based surfactants alkyl polyglucoside (APG), tea saponin (TAS), waterborne polyurethane (WPU), tartaric acid (TA), and sodium chloride (NaCl) in order to remove radioactive contamination on the surface of nuclear emergency and decommissioning facilities in low temperature environment. Additionally, the composition of foam detergent was optimized by response surface methodology. The foaming, stability, wall-hanging property of antifreeze foam detergent and its decontamination properties of simulated radioactive pollution under low temperature environment were studied. The surface tension, viscosity, and wettability of antifreeze foam detergent and the decontamination mechanism at low temperature were analyzed. The results show that at the low temperature of − 10 ºC, the foaming multiple of the foam detergent is 14.37, the half-life is 44.43 min, and the wall-hanging time on the surface of vertical ceramic tile is 60 min. Within 30 min, the decontamination factors of simulated radioactive contamination on the surface of the glass, ceramic tile, stainless steel, and lacquered board by antifreeze foam detergent are 17.83, 12.82, 12.03, and 14.83, respectively. Environmentally friendly antifreeze foam detergent with high foaming property, outstanding wall-hanging property, and decontamination ability has broad application prospects in nuclear emergency and decommissioning of nuclear facilities in low temperature environments in winter.

Surfactant formulation for Green Enhanced Oil Recovery

While the world continues to rely heavily on petroleum as a primary energy source, a great fraction of the oil-in-place remains inaccessible to traditional recovery means (thermal, gas, or chemical), posing significant environmental consequences and high treatment costs. Green enhanced oil recovery (GEOR) technologies, on the other hand, have generated interest in energy research as it involves the injection of specialized green fluids into reservoirs to improve sweep efficiency while also increasing residual oil production. Surfactant flooding, for example, has emerged as a viable green chemical EOR approach in which bioproducts produced by microbial metabolic processes are introduced into the reservoir to increase oil production These green surfactants (e.g., rhamnolipid, alkyl polyglycoside (APG), and lecithin) are now being studied for their possible uses in EOR processes as they have not been completely explored for their potential in chemical EOR. Therefore, in this study, a blend of rhamnolipid, APG, and lecithin are considered possible formulations to investigate the efficacy of these green surfactants in sandstone reservoirs based on phase behavior studies, interfacial tension measurement, and core-flooding experiments. It was found that all three blends (RB, RAB, and RL) performed well in the phase behavior study, resulting in stable middle phase microemulsions whereas only formulation RL had an ultralow IFT reduction between oil and brine. Consequently, this formulation (RL) performed the best of the three, with a tertiary recovery of 24% and a total recovery of approximately 70%. These results suggest that while other blends (RB and RAB) had good EOR potential, the third formulation (RL) is considered a more appropriate candidate for chemical EOR with a preference for biosurfactants (rhamnolipids) application. The outcomes of this study can aid in a better understanding of injection design methods and biosurfactant formulation selection, which is a critical attribute for green EOR technology.

Alkyl polyglycosides enhanced the dark fermentation of excess sludge and plant waste to produce hydrogen: performance and mechanism.

Alkyl polyglycosides (APG), a biodegradable biosurfactant, have been widely used in environmental pollution control. However, the application of APG to enhance anaerobic dark fermentation of excess sludge (ES) and plant waste (PW) to improve hydrogen production has not been reported so far. In order to fill this gap, the effect of APG on hydrogen production from ES and PW was studied in mesophilic (30 °C) environment. The results showed that APG increased the yield of hydrogen, and the recommended dose was 0.15 g/g (calculated as volatile suspended solids), accompanied by 18.7 mL/g. The contribution of APG self-degradation to hydrogen can be ignored. Mechanism investigation revealed that APG promoted the dissolution, hydrolysis, and acidification of complex organic matter, and when the content of APG was 0.15 g/g, the concentration of dissolved chemical oxygen demand (COD) was as high as 3151 mg/L; however, the dissolved concentration of COD in the blank group was only 1548 mg/L. In addition, APG improved the output of volatile fatty acids (VFA). APG promoted the proportion of acetate and butyrate in VFA, which was conducive to hydrogen production. As for the process of methanogenesis, APG reduced the consumption of hydrogen and accumulates hydrogen. This work provides an alternative strategy for the recycling of organic waste and the enhanced generation of hydrogen.

STUDY OF THE PROPERTIES OF SURFACE-ACTIVE SUBSTANCES DETERMINING THE EFFICIENCY OF DYING AND RINSING OF TEXTILE MATERIALS

The article studies the most important properties of surfactants – foaming and wetting ability, stability in a highly alkaline environment, surface activity. Spectrophotometric method showed the intensifying effect of environmentally friendly surfactants Glucopon 2015 and Carboxypav on the process of colouring natural textile materials with dichlorotriazine, vinyl sulfone and bifunctional dyes. The effect of surfactants of various structures on the state of the active dye in solution and the technical results of colouring cellulose and cotton silk fabrics has been evaluated. A synergistic effect of the solubilising action of surfactants – nonionic alkyl polyglycosides (Glucopon 215) and anionic carboxylates (Carboxypav) on active dyes was revealed.

Evaluation of Chelating Agents Used in Phytoextraction by Switchgrass of Lead Contaminated Soil.

Soil lead (Pb) contamination is a recognized environmental and global health problem. Phytoextraction of Pb using switchgrass (Panicum virgatum L.), a second-generation biofuel crop, is typically enhanced by soil chelation. The effectiveness of four different chelating agents, phytic acid (inositol hexaphosphate), citric acid, NTA (nitrilotriacetic acid), and EDTA (ethylenediaminetetraacetic acid) was examined in pot culture. Plants treated with EDTA (1 mM) showed significantly higher shoot Pb concentrations compared to control plants and plants treated with other chelates. Lead-solubility following phytoextraction was examined by soil washing using 0.01 and 0.05 M acetic acid as an extractant solution revealed no significant differences in Pb concentrations in soil among different chelate treatments and control. Furthermore, the effects of different concentrations (1, 2, 5 and 10 mM) of NTA on Pb phytoextraction of switchgrass were examined. Plants receiving 5 mM and 10 mM NTA had significantly higher foliage concentrations of Pb compared to plants treated with lower levels (1 and 2 mM) of NTA. Moreover, the effect of NTA application alone was significantly improved by a combined application of Triton X-100, an alkyl polyglucoside (APG); the Pb concentration in the foliage of switchgrass was more than doubled when treated with NTA combined with APG. The use of NTA combined with APG has great potential in improving phytoextraction efficiencies of switchgrass on Pb-contaminated soils.

Synthetic and Natural Surfactants for Potential Application in Mobilization of Organic Contaminants: Characterization and Batch Study

In this paper, we investigated the abilities of five sugar-based synthetic surfactants and biosurfactants from three different families (i.e., alkyl polyglycoside (APG), sophorolipid (SL), and rhamnolipid (RL)) to dissolve and mobilize non-aqueous phase liquid (NAPL) components, i.e., toluene and perchloroethylene (PCE), adsorbed on porous matrices. The objective of this study was to establish a benchmark for the selection of suitable surfactants for the flushing aquifer remediation technique. The study involved a physicochemical characterization of the surfactants to determine the critical micelle concentration (CMCs) and interfacial properties. Subsequently, a batch study, through the construction of adsorption isotherms, made it possible to evaluate the surfactants’ capacities in contaminant mobilization via the reduction of their adsorptions onto a reference adsorbent material, a pine wood biochar (PWB). The results indicate that a synthetic surfactant from the APG family with a long fatty acid chain and a di-rhamnolipid biosurfactant with a shorter hydrophobic group offered the highest efficiency values; they reduced water surface tension by up to 54.7% and 52%, respectively. These two surfactants had very low critical micelle concentrations (CMCs), 0.0071 wt% and 0.0173 wt%, respectively; this is critical from an economical point of view. The batch experiments showed that these two surfactants, at concentrations just five times their CMCs, were able to reduce the adsorption of toluene on PWB by up to 74% and 65%, and of PCE with APG and RL by up to 65% and 86%, respectively. In general, these results clearly suggest the possibility of using these two surfactants in surfactant-enhanced aquifer remediation technology.

Date-Leaf Carbon Particles for Green Enhanced Oil Recovery.

Green enhanced oil recovery (GEOR) is an environmentally friendly enhanced oil recovery (EOR) process involving the injection of green fluids to improve macroscopic and microscopic sweep efficiencies while boosting tertiary oil production. Carbon nanomaterials such as graphene, carbon nanotube (CNT), and carbon dots have gained interest for their superior ability to increase oil recovery. These particles have been successfully tested in EOR, although they are expensive and do not extend to GEOR. In addition, the application of carbon particles in the GEOR method is not well understood yet, requiring thorough documentation. The goals of this work are to develop carbon nanoparticles from biomass and explore their role in GEOR. The carbon nanoparticles were prepared from date leaves, which are inexpensive biomass, through pyrolysis and ball-milling methods. The synthesized carbon nanomaterials were characterized using the standard process. Three formulations of functionalized and non-functionalized date-leaf carbon nanoparticle (DLCNP) solutions were chosen for core floods based on phase behavior and interfacial tension (IFT) properties to examine their potential for smart water and green chemical flooding. The carboxylated DLCNP was mixed with distilled water in the first formulation to be tested for smart water flood in the sandstone core. After water flooding, this formulation recovered 9% incremental oil of the oil initially in place. In contrast, non-functionalized DLCNP formulated with (the biodegradable) surfactant alkyl polyglycoside and NaCl produced 18% more tertiary oil than the CNT. This work thus provides new green chemical agents and formulations for EOR applications so that oil can be produced more economically and sustainably.