A study of synergetic carrier emulsion liquid membrane for the extraction of amoxicillin from aqueous phase using response surface methodology

The Latest Achievements of Liquid Membranes for Rare Earth Elements Recovery from Aqueous Solutions-A Mini Review

The systematic increase in the use of rare earth elements (REEs) in various technologically advanced products around the world (e.g., in electronic devices), the growing amount of waste generated by the use of high-tech materials, and the limited resources of naturally occurring REE ores resulted in an intensive search for effective and environmentally safe methods for recovering these elements. Among these methods, techniques based on the application of various types of liquid membranes (LMs) play an important role, primarily due to their high efficiency, the simplicity of membrane formation and use, the utilization of only small amounts of environmentally hazardous reagents, and the possibility of simultaneous extraction and back-extraction and reusing the membranes after regeneration. However, because both primary and secondary sources (e.g., waste) of REEs are usually complex and contain a wide variety of components, and the selectivity and efficiency of LMs depend on many factors (e.g., the composition and form of the membrane, nature of the recovered ions, composition of the feed and stripping phases, etc.), new membranes are being developed that are "tailored" to the properties of the recovered rare earth elements and to the character of the solution in which they occur. This review describes the latest achievements (since 2019) related to the recovery of a range of REEs with the use of various liquid membranes (supported liquid membranes (SLMs), emulsion liquid membranes (ELMs), and polymer inclusion membranes (PIMs)), with particular emphasis on methods that fall within the trend of eco-friendly solutions.

Synthesis of AgNPs from waste mobile phone circuit boards using an emulsion liquid membrane method

The disposal of mobile phone print circuit boards (WMPCBs) has now been a problem because of the continually increasing production of mobile phones. It could be considered a new source of precious metal but may jeopardize the environment and human health without proper management. An emulsion liquid membrane (ELM) method is applied and improved to recover silver from WMPCBs and prepare AgNPs. The effects of significant operating parameters were studied for a better understanding of the ELM process. Under the optimized conditions i.e., 0.25 % (v/v) Cyanex 302, 6 % (v/v) Span 80, 5 % (w/v) ASC, 3500 rpm emulsification speed, 10 min emulsification time, 300 rpm extraction stirring speed, 10 min extraction stirring time and 3 (v/v) phase ratio, 98.7 % silver was extracted. AgNPs produced were flower structures assembled by a group of individual nanosheets with a diameter of 800-1400 nm and a thickness of 10-14 nm. The purity was 98.7 % and the yield was 96.6 %. AgNPs of oblate spheroidal structure with a diameter of 30-50 nm could be synthesized by controlling the concentration of Span 80 in ELM. The current study intends to fulfill the gap by exploring the recovery of silver from WMPCBs by the ELM method.

Construction and formulation optimization of prothioconazole nanoemulsions for the control of Fusarium graminearum: Enhancing activity and reducing toxicity

In this study, the optimal emulsifier for prothioconazole nanoemulsions was initially screened based on appearance, microscopic observation, mean droplet size and polydispersity index (PDI). In addition, the BoxBehnken design method is adopted, and the optimal formula is screened with an emulsification time, emulsifier content, and solvent content as a single factor. On this basis, the nanoemulsion meets FAO standards for various indicators. The contact angle of droplets on wheat leaves was significantly reduced. This nanoemulsion also showed good inhibitory activity against Fusarium graminearum (EC₅₀ =1.94 mg L^-1), low acute toxicity to zebrafish (LC₅₀ =26.35 mg L^-1) and good biosafety to BEAS-2B cells. The nanoemulsion reduced the adverse effects of pesticide on wheat seed germination and growth. This study can help promote the design and manufacture of stable, efficient and safe agricultural nanoemulsions, and is expected to benefit the sustainable development of green plant protection.

Optimization and Prediction of Stability of Emulsified Liquid Membrane (ELM): Artificial Neural Network

In this work, the emulsified liquid membrane (ELM) extraction process was studied as a technique for separating different pollutants from an aqueous solution. The emulsified liquid membrane used consisted of Sorbitan mono-oleate (Span 80) as a surfactant with n-hexane (C6H14) as a diluent; the internal phase used was nitric acid (HNO3). The major constraint in the implementation of the extraction process by an emulsified liquid membrane (ELM) is the stability of the emulsion. However, this study focused first on controlling the stability of the emulsion by optimizing many operational factors, which have a direct impact on the stability of the membrane. Among the important parameters that cause membrane breakage, the surfactant concentration, the emulsification time, and the stirring speed were demonstrated. The optimization results obtained showed that the rupture rate (Tr) decreased until reaching a minimum value of 0.07% at 2% of weight/weight of Span 80 concentration with an emulsification time of 3 min and a stirring speed of 250 rpm. On the other hand, the volume of the inner phase leaking into the outer phase was predicted using an artificial neural network (ANN). The evaluation criteria of the ANN model in terms of statistical coefficient and RMSE error revealed very interesting results and the performance of the model since the statistical coefficients were very high and close to 1 in the four phases (R_training = 0.99724; R_validation = 0.99802; R_test = 0.99852; R_all data = 0.99772), and also, statistical errors of RMSE were minimal (RMSE_training= 0.0378; RMSE_validation = 0.0420; RMSE_test = 0.0509; RMSE_all data = 0.0406).

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.

Application of Response Surface Methodology (RSM) for the Optimization of Chromium(III) Synergistic Extraction by Supported Liquid Membrane

In this paper, the response surface methodology (RSM) was proposed for studying the synergistic extraction of chromium(III) ions by double-carrier supported liquid membrane (DCSLM) with organophosphorus carriers (D2EHPA/Cyanex272). At first, the optimization method of "one-factor-at-a-time" was adopted for determination of the best conditions for Cr(III) extraction by SLM with only one carrier (D2EHPA). The optimum/threshold D2EHPA concentration in the membrane phase increased linearly with initial concentration of Cr(III) ions in the feed phase. After the addition the second carrier (Cyanex272), the synergistic effect was observed. The largest percentage of extraction and the shorter time was obtained. The optimization of the synergistic extraction in DCSLM system by RSM using Box-Behnken design (BBD) for three variables (concentration and proportions of the carriers, initial concentration of Cr(III), and time of the process) was studied. The statistical model was verified with the analysis of variance (ANOVA) for the response surface quadratic model. The reduced quadratic model showed that the predicted values were in agreement with those obtained experimentally, as well as the fact that the concentrations and proportions of the carriers had a significant influence on the response. The developed model was considered to be verified and can be used to predict the optimal condition for the chromium ions extraction.