Green Diluent Research Articles

Utilization of Green Diluent on the Removal for Heavy Metal Contaminants Using Emulsion Liquid Membrane

Utilization of Green Diluent on the Removal for Heavy Metal Contaminants Using Emulsion Liquid Membrane

Removal of Phenol Contaminants from Aqueous Solution Using Pickering Emulsion Liquid Membrane Stabilized by Magnetic Nano-Fe3O4

In the current study, the effect of the nonionic surfactant (span 80) on the emulsification of a mixture of kerosene as a petroleum-based organic solvent and span80 as a green diluent in the ratio 1:1 was investigated. NaOH was used as the internal phase, and the stability of the emulsion was tested. The potential for extracting phenol from aqueous solutions without the use of a carrier agent has been explored using Pickering emulsion liquid membrane. Additionally, the impacts of experimental parameters include homogenizer speed, mixing speed, emulsification time, Fe3O4-Span 80 ratios, NaOH concentration, and internal to membrane volume ratio (I/O) on extraction effectiveness and emulsion stability. The findings demonstrated that after 9 minutes of contact time and a minimum breaking percent of 0.745% under ideal circumstances, more than 96% of phenol could be recovered. In addition thermodynamic analysis reveals that the extraction process was an endothermic and spontaneous in nature and the overall mass transfer coefficient was 1.115 m/s. Membrane materials and nanoparticles were recycled four time in the extraction of phenol with approximately the same efficiency and no significant breakage percent..

Extractive extraction for platinum recovery using synergistic organic formulation of Aliquat 336/TBP mixtures

The source of platinum in the earth’s crust has become diminishing nowadays, thus recycling platinum from a secondary source is highly demanded. Hydrometallurgical processes have been used as an alternative method instead of pyrometallurgical. In this process, extractive solvent extraction is the core of operations. This study aims to find the synergistic formulation for platinum extraction as well as to study the extraction and stripping mechanism of the separation process. The extraction was performed by using a synergist organic formulation of basic and solvating where Aliquat 336 and tributyl phosphate (TBP) were used as a base and synergist extractant, respectively. Palm cooking oil was used as a green diluent. At 5x10-5 M TBP + 5x10-4 M Aliquat 336, 85% of platinum was extracted and the synergistic coefficient (SC) in this work was 1.29. Aliquat 336 acts as a synergist while TBP acts as a base. Based on the mechanism, it was concluded that one mole of Aliquat 336 and one mole of TBP can extract one mole of platinum ion. Then, the stripping process of the loaded extractant/platinum was done using the mixture of HCl and thiourea. At the optimum concentration of the stripping agent (0.5 M HCl + 0.5 M thiourea), 93% platinum was stripped which was considered a high stripping efficiency. Therefore, the synergistic formulation of the extractive extraction process offers great potential for platinum recovery from the aqueous solution.

Evaluation of alginate hydrogel stabilized Pickering emulsion liquid membrane for methylene blue extraction from aqueous solutions

In this work, the potential of an alginate hydrogel stabilized Pickering emulsion liquid membrane (PELM) for methylene blue (MB) extraction from aqueous solution was investigated. The waste cooking oil (WCO) was used as a green diluent, aliquat 336 was used as a carrier, and potassium hydroxide (KOH) was used as a stripping agent to synthesize PELM. The use of WCO replaces the hazardous and ecologically harmful petroleum-based organic solvents that are frequently employed in PELM production. The MB removal was maximum at internal phase concentration 1:5, initial external feed phase concentration 5 ppm, emulsifier concentration 1% (w/w), carrier concentration 20% (w/w) and O/A ratio 1:1. The mechanism of MB extraction by PELM was elucidated. The maximum extraction efficiency was 91.58% at optimum condition. The kinetic study revealed that the MB extraction by PELM followed a zero-order reaction. Furthermore, thermodynamic analysis indicated that the extraction process was both endothermic and spontaneous in nature. Overall, the findings of this study demonstrate the potential of PELM as a promising technique for the extraction of MB from aqueous solutions using alginate hydrogel as an eco-friendly and sustainable materials.

Recovery of copper and silver from industrial e-waste leached solutions using sustainable liquid membrane technology: a review

Waste electrical and electronic equipment or e-waste has recently emerged as a significant global concern. This waste contains various valuable metals, and via recycling, it could become a sustainable resource of metals (viz. copper, silver, gold, and others) while reducing reliance on virgin mining. Copper and silver with their superior electrical and thermal conductivity have been reviewed due to their high demand. Recovering these metals will be beneficial to attain the current needs. Liquid membrane technology has appeared as a viable option for treating e-waste from various industries as a simultaneous extraction and stripping process. It also includes extensive research on biotechnology, chemical and pharmaceutical, environmental engineering, pulp and paper, textile, food processing, and wastewater treatment. The success of this process depends more on the selection of organic and stripping phases. In this review, the use of liquid membrane technology in treating/recovering copper and silver from industrial e-waste leached solutions was highlighted. It also assembles critical information on the organic phase (carrier and diluent) and stripping phase in liquid membrane formulation for selective copper and silver. In addition, the utilization of green diluent, ionic liquids, and synergist carrier was also included since it gained prominence attention latterly. The future prospects and challenges of this technology were also discussed to ensure the industrialization of technology. Herein, a potential process flowchart for the valorization of e-waste is also proposed.

Removal of low concentration ibuprofen using green diluent and novel formulated supported ionic liquid membrane

Removal of pharmaceutical micropollutants is critical to reduce detrimental contaminants found in the environment. The current study focuses on developing a new formulation of supported ionic liquid membrane (SILM) for removing low concentration of ibuprofen (IBP) using green diluent and ionic liquid. Parameters such as solid support properties, variation of diluents, type of carrier and carrier concentration are investigated. The results demonstrate that liquid carrier consisted of sunflower oil (SFO) and Aliquat 336 successfully impregnated on the PVDF support via FTIR and SEM analysis. Liquid carrier loss from the PVDF support is less than 1% by impregnating green diluents consisting of SFO. 18PVDF-DMAC/300 is selected owing to its asymmetric finger-like and spongy structure with porosity, mean pore diameter, contact angle and thickness of (82.2 ± 0.7) %, (0.19 ± 0.01) μm, (89.4 ± 0.2)° and (90.3 ± 0.8) μm, respectively. Under 72-hour operation, a maximum extraction and stripping efficiency are obtained at 93% and 87% respectively, indicating a stable SILM process. Results obtained suggest that the newly formulated SILM is advantageous and may be used to extract low concentrations of IBP from the feed phase.

Bioremoval of methylene blue dye using chitosan stabilized Pickering emulsion liquid membrane: optimization by Box–Behnken response surface design

Chitosan, an eco-friendly biopolymer, was employed as a novel emulsifier in the sequestration of methylene blue (MB) dye from aqueous solution using Pickering emulsion liquid membrane (PELM). In the present study the PELM consists of aliquat 336 as extractant, potassium hydroxide (KOH) as a stripping agent, and coconut oil as the green diluent. Response surface methodology derived from Box–Behnken design (BBD) was applied for optimizing the operational parameters affecting the MB extraction. The results obtained from BBD design showed the maximum extraction of 89.99% at chitosan concentration of 0.10 w/v %, KOH (Internal phase) concentration of 0.8 M, MB concentration of 7.5 ppm, O/A ratio of 1 and stirring speed of 400 rpm. Investigations proved that chitosan biopolymer an eco-friendly emulsifying agent can be successfully used in PELM preparation for the extraction of dye bearing wastewater.

Extraction of methylene blue from aqueous solution by pickering emulsion liquid membrane using cellulose as eco-friendly emulsifier: optimization and modeling studies.

In the present investigation cellulose, a naturally occurring biopolymer, was used as an eco-friendly emulsifier for the removal of methylene blue (MB) from simulated wastewater using emulsion liquid membrane. Coconut oil, a green diluent, was used as an organic phase in preparing a pickering emulsion liquid membrane (PELM) the extraction of dye. The PELM was prepared by loading with aliquat 336 as extractant, potassium hydroxide (KOH) as internal phase, and edible coconut oil as the diluent. The effect of the process parameters such as dye concentration, internal phase concentration, emulsifier concentration, organic phase to aqueous phase (O/A) ratio, stirring speed (RPM) were studied using Box-Behnken design and response surface method. The results showed that more than 92% of MB were successfully extracted around 120 min. Hence, it could be concluded that cellulose can be used as a promising emulsifying agent in the PELM preparation for the removal of MB from wastewater.

Stability and performance studies of emulsion liquid membrane on pesticides removal using mixture of Fe3O4Â nanoparticles and span80

• Study the effect of Span 80 and Fe3O4on the stability of emulsion liquid membrane. • Investigate the effect of different parameters on the stability and extraction efficiency. • 99% of Abamectin extracted and 0.52% breakage percent achieved at the best conditions. • The extraction kinetic and mass transfer coefficient were accomplished. The current study investigated the impact of nonionic surfactant span 80 in the existence of Fe 3 O 4 magnetic nanoparticles on the emulsification of mixture of kerosene as petroleum based organic solvents and corn oil as a green diluent in the ratio 1:1, HCl was used as internal phase and the stability of the emulsion was carried out. The proposed Pickering emulsion liquid membrane has been exploited to investigate it is ability in the extraction of Abamectin pesticides from aqueous solution without utilizing carrier agent. Further, the effects of experimental parameters on extraction efficiency and emulsion stability such as, homogenizer speed, emulsification speed, contact time, Fe 3 O 4 -Span 80 ratios, HCL concentration, internal to membrane volume ratio (I/O) and pH of the external feed solution were carried out. The results showed that more than 99% of Abamectin could be extracted at 10 min contact time with a minimum breakage percent of 0.52% at the optimal conditions. The kinetic of the extraction were studied and the mass transfer coefficient was found to be for external phase ( K M ) of 1.2 × 10 − 7 , interfacial reaction rate constant ( K F ) of 5.83 × 10 − 8 and the overall mass transfer coefficient ( K O ) of 3.91 × 10 − 8 . The results of recyclability of the PELM revealed that the emulsion stability and extraction efficiency was nearly unchanged after three cycles.

Vegetable Oil-Ionic Liquid-Based Emulsion Liquid Membrane for the Removal of Lactic Acid from Aqueous Streams: Emulsion Size, Membrane Breakage, and Stability Study.

In this study, we present a highly stable vegetable oil ionic liquid (IL)-based emulsion liquid membrane (VOILELM) for the removal of lactic acid from water streams. The system developed as a part of this work comprises a non-ionic surfactant Span 80, sodium hydroxide as an internal stripping agent, sunflower canola oil as a green diluent, and IL—tetramethylammonium acetate [TMAm][Ac]—as a carrier. VOILELM stability was evaluated in terms of breakage, emulsion diameter, and standalone stability. The effect of various parameters, namely, concentration of the surfactant, concentration of the internal stripping agent, concentration of the carrier, phase ratio, homogenizer speed, and homogenization time, on the VOILELM stability was studied. The results revealed that VOILELM was highly stable, with 1.34% minimum breakage, 1.16 μm emulsion diameter, and 131 min standalone stability. The optimal process parameters were 0.1 wt % Span 80, 0.1 M NaOH, 0.3 wt % IL, 0.25 phase ratio, 5000 rpm homogenizer speed, and 5 min homogenization time. At these optimized conditions, 96.08% lactic acid extraction efficiency was achieved. Thus, a highly effective VOILELM was developed, with minimal breakage and emulsion diameter and maximum stability.

Emulsion Liquid Membrane Screening for Ibuprofen Removal from Aqueous Solution

Ibuprofen (IBP) has become increasingly widespread in our environment, posing a major problem for treatment by its high occurrence in low concentrations. Emulsion liquid membrane (ELM) technology has emerged as an alternative solution for removing low concentration pollutants from contaminated sources. This study screened ELM formulations for the removal of IBP from an aqueous solution. Emulsion screening was conducted using a series of reactants, including petroleumbased diluent, green diluent, and acidic/alkaline stripping agent. The ELM system, which included hexane (diluent), 0.1 M sodium carbonate, Na2CO3 (stripping agent), 2 wt% Aliquat 336 (carrier) and 4 wt% Span 80 (surfactant), achieved the highest IBP extraction efficiency of 97%.

A Novel Green Diluent for the Preparation of Poly(4-methyl-1-pentene) Membranes via a Thermally-Induced Phase Separation Method.

The use of green solvents satisfies safer chemical engineering practices and environmental security. Herein, myristic acid (MA)—a green diluent—was selected to prepare poly- (4-methyl-1-pentene) (PMP) membranes with bicontinuous porous structure via a thermally induced phase separation (TIPS) process to maintain a high gas permeability. Firstly, based on the Hansen solubility parameter ‘distance’, Ra, the effect of four natural fatty acids on the PMP membrane structure was compared and studied to determine the optimal green diluent, MA. The thermodynamic phase diagram of the PMP-MA system was calculated and presented to show that a liquid-liquid phase separation region could be found during the TIPS process and the monotectic point was around 34.89 wt%. Then, the effect of the PMP concentration on the morphologies and crystallization behavior was systematically investigated to determine a proper PMP concentration for the membrane preparation. Finally, PMP hollow fiber (HF) membranes were fabricated with a PMP concentration of 30 wt% for the membrane performance characterization. The resultant PMP HF membranes possessed good performances that the porosity was 70%, the tensile strength was 96 cN, and the nitrogen flux was 8.20 ± 0.10 mL·(bar·cm2·min)−1. We believe that this work can be a beneficial reference for people interested in the preparation of PMP membranes for medical applications.

Effect of the molecular weight of polymer and diluent on the performance of hydrophilic poly(vinyl butyral) porous heddle via thermally induced phase separation

Hydrophilic Poly (vinyl butyral) (PVB) porous heddles were prepared via blending hydrophilic PVB and green diluent Polyethylene glycol (PEG) through liquid-liquid thermally induced phase separation (TIPS) process. To further investigate the effect of the molecular weight (MW) of polymer and diluent on phase diagram of PVB-PEG blending system and performance of hydrophilic PVB porous heddle, the cloud point (Tcloud), microstructure, overall porosity and mechanical property, i.e were mainly analyzed. The results highlighted that the Tcloud of the PVB-PEG blending shifted to lower temperature with increasing PEG MW and PVB MW. Overall porosity reached up to 82.3% and tensile strength was 9.88 MPa when polymer and diluent with lowest MW. To extend the application air, the fabrication conditions of prepared porous heddle were studied. Overall porosity increased and the tensile strength decreased with extrusion temperature increasing. In addition, the PVB-PEG porous heddles proved effective hydrophilic performance and demonstrate the potential application in water treatment.

Application of a green emulsion liquid membrane for removing copper from contaminated aqueous solution: Extraction, stability, and breakage study using response surface methodology

In the current study, the process of sunflower oil-based green emulsion liquid membrane (GELM) has been investigated for the separation of copper ions from aqueous solutions. The liquid membrane was prepared by loading with Span 80 as the surfactant, D2EHPA as the carrier, sunflower oil as the solvent and hydrochloric acid as the aqueous internal phase. The effect of the process parameters such as concentration of the surfactant, concentration of HCl, concentration of D2EHPA and the ratio of the internal phase to the organic phase in the membrane were studied using Box-Behnken design and response surface method. The results showed that more than 94% of Cu(II) ions were successfully extracted within 130 min at the optimum conditions of 104.23 mM D2EHPA, 1.44 M HCl, 3.25 wt% Span 80 and an I/O ratio of unity providing a stable emulsion. Hence, it could be concluded that sunflower oil may be considered as a high potential green diluent in water treatment and purification technology, particularly in ELM process for the removal of Cu(II) from wastewater.

Development of Palm Oil-Based Synergist Liquid Membrane Formulation for Silver Recovery from Aqueous Solution

In this work, the palm oil-based synergist formulation containing a mixture of carriers for liquid membrane application of silver recovery from aqueous solution was studied. Several types of acidic carrier mixtures were investigated via liquid-liquid extraction procedure to increase the extraction performance. The results indicated that palm cooking is a promising vegetable oil-based green diluent in the formulation. A carrier mixture of 0.2 mM Cyanex 302 and 0.3 mM Cyanex 272 demonstrated synergism during the extraction process. It was found that more than 98% of silver ions from a very dilute solution was effectively extracted with a synergistic coefficient of 62.7. According to the individual and carrier mixture results, it can be deduced that Cyanex 272 and Cyanex 302 served as a carrier and synergist, respectively. Therefore, the developed liquid membrane formulation showed great prospect in silver recovery from the liquid waste solution.

Valorization of palm oil mill sterilization condensate via synergistic green reactive extraction of bioactive compounds

Palm oil mill (POM) sterilization condensate is recognized as the source of polyphenols with interesting biological activities, for example, inflammatory processes prevention, UV protection, antioxidant, antimicrobial, and anticarcinogen. Reactive extraction is one of the promising methods for bioactive compounds (polyphenols) recovery offering various merits such as simple, efficient, easy to scale up, and high selectivity. In this work, reactive extraction of polyphenols from POM sterilization condensate using synergistic organic formulation was investigated. The extraction was performed by screening several base and synergist extractants using palm cooking oil as a green diluent. The results showed that about 85% of polyphenols were extracted using 0.25 M 1-Octanol and 0.05 M Aliquat 336 with a synergistic coefficient of 2.59. Meanwhile, the back-extraction study demonstrated that 0.3 M NaOH was selected as the most appropriate stripping agent where almost 100% of stripping performance was achieved. Therefore, the synergistic green formulation offers great potential for polyphenols recovery from POM sterilization condensate.

Emulsion liquid membrane extraction of polyphenols compound from palm oil mill effluent

Polyphenols possess many health attributes, as they are powerful antioxidants. Recovery of value-added compounds from industrial waste is a new approach in order to promote sustainability. In this study, the extraction of polyphenols from palm oil mill sterilization condensate by emulsion liquid membrane (ELM) process is proposed. The sterilization condensate was first characterized to determine the total phenolic content (TPC) in the sample. For the extraction, liquid membrane was formulated to choose the best diluent, carrier, and stripping agent. Once the formulation was successfully attempted, the extraction of polyphenols to recover polyphenols was performed. The results show that 2627.3 mg GAE/L of TPC was obtained in the condensate. During the liquid membrane formulation, palm oil was chosen as a green diluent, TBP and n-Octanol were selected as the most appropriate carriers for synergize in a composition of 8:2 by volume, while sodium hydroxide was selected as the most appropriate stripping agents to best facilitate the extraction process. The extraction and recovery performance of polyphenols showed performance of 96.5% and 31%, respectively. The findings of this study show that ELM is a potential technology to extract and recover polyphenols from palm oil mill sterilization condensate.

Fabrication of poly(vinylidene fluoride) membrane via thermally induced phase separation using ionic liquid as green diluent

Ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6) as a new and environmentally friendly diluent was introduced to prepare poly(vinylidene fluoride) (PVDF) membranes via thermally induced phase separation (TIPS). Phase diagram of PVDF/[BMIM]PF6 was measured. The effects of polymer concentration and quenching temperature on the morphologies, properties, and performances of the PVDF membranes were investigated. When the polymer concentration was 15 wt%, the pure water flux of the fabricated membrane was up to nearly 2000 L·m −2 ·h −1 , along with adequate mechanical strength. With the increasing of PVDF concentration and quenching temperature, mean pore size and water permeability of the membrane decreased. SEM results showed that PVDF membranes manufactured by ionic liquid (BMImPF6) presented spherulite structure. And the PVDF membranes were represented as β phase by XRD and FTIR characterization. It provides a new way to prepare PVDF membranes with piezoelectric properties.

Parametric optimization of green synergistic reactive extraction of lactic acid using trioctylamine, Aliquat336, and butan-2-ol in sunflower oil by response surface methodology

A novel green synergistic reactive extraction technique for the removal of lactic acid (LA) from aqueous solution was explored. Response surface methodology (RSM) was applied to optimize the process variables for LA synergistic reactive extraction using a mixture of trioctylamine and Aliquat336 as extractants. During this present investigation, 2-butanol and sunflower oil were used as organic and green diluent. Systematic investigation has been carried out to obtain the optimum process conditions viz. initial LA concentration, pH of aqueous solution, extractant ratio, extractant concentration, solvent ratio, phase ratio, temperature, stirring speed, and contact time for maximizing the LA distribution coefficient (KD) and extraction efficiency (%, η). The highest experimentally achievable LA distribution coefficient (KD) and extraction efficiency (%) at optimized process conditions were found to be in close agreement with those predicted by numerical optimization using RSM. Thus, the results of present finding have been shown a great ability of sunflower oil as an economic and environmentally friendly green solvent for LA extraction.

Extraction of hexavalent chromium by environmentally benign green emulsion liquid membrane using tridodecyamine as an extractant

In this present investigation, the potentiality of rice bran oil (RBO) and tridodecylamine (TDDA) to be incorporated as the key constituents in the formulation of new environmentally benign green emulsion liquid membrane (GELM) to extract hexavalent chromium (Cr(VI)) from aqueous feed phase was explored. The pertinent constituents of GELM were RBO (70%, v/v) and hexane (30%, v/v) as green and organic diluent, respectively; TDDA (0.75 (%, v/v) of diluent solution) as carrier; emulsifying agent (span 80: 1.75 (%v/v) of diluent solution); and NaOH as internal reagent. The investigation of optimum process conditions for various parameters has resulted in 0.45pH of aqueous solution, 0.25 [M] internal phase concentration, 2:1 (v/v) treat ratio, 0.40 (v/v) phase ratio, 550 (rpm) agitation speed, 25 (min) extraction time, and 30±2 (°C) feed phase temperature. The highest achievable extraction efficiency (η, %) and dynamic stability (min) of GELM have been obtained as 97±2% and 150±2min, respectively under these optimum process conditions. The present finding has revealed that RBO as a green diluent has huge capability to be further utilized for the extraction of Cr (VI) from various industrial effluent streams.