Effects of process factors on performances of liquid membrane-based transfer of indole-3-acetic acid

The paper has aimed at studying the transfer of indole 3-acetic acid (IAA) from a feed aqueous solution to a stripping aqueous solution of NaOH using a chloroform bulk liquid membrane and trioctylamine (TOA) as a ligand (L). Initial molar concentrations of IAA in the feed phase, cIAA,F0 (10–4–10–3 kmol/m3), of TOA in the membrane phase, cL,M0 (10–2 and 10–1 kmol/m3), and of NaOH in the stripping phase, cNaOH,S0 (10–2 and 1 kmol/m3), were selected as process factors. Their effects on the final values of IAA concentration in the feed phase (cIAA,Ff) and stripping solution (cIAA,Sf), extraction efficiency (EF), distribution coefficient (KD), and recovery efficiency (ER) were quantified using multiple regression equations. Regression coefficients were determined from experimental data, i.e., cIAA,Ff,ex = 0.02–1 × 10–4 kmol/m3, cIAA,Sf,ex = 0.22–2.58 × 10–3 kmol/m3, EF,ex = 90.0–97.9%, KD,ex = 9.0–46.6, and ER,ex = 66.5–94.2%. It was found that cIAA,F0 had the most significant positive effect on cIAA,Ff and cIAA,Sf, whereas cNaOH,S0 had a major positive effect on EF, KD, and ER. A deterministic model based on mass transfer of IAA was developed and its parameters, i.e., mass transfer coefficient of IAA-L complex in the liquid membrane (0.82–11.5 × 10–7 m/s) and extraction constant (1033.9–1779.7 m3/kmol), were regressed from experimental data. The effect of cL,M0 on both parameters was significant.

Effects of Process Factors on Performances of Liquid Membrane-Based Transfer of Indole-3-Acetic Acid

The paper has aimed at studying the transfer of indole 3-acetic acid (IAA) from a feed aqueous solution to a stripping aqueous solution of NaOH using a chloroform bulk liquid membrane and trioctylamine (TOA) as a ligand (L). Initial molar concentrations of IAA in the feed phase, cIAA,F0 (10-4-10-3 kmol/m3), of TOA in the membrane phase, cL,M0 (10-2 and 10-1 kmol/m3), and of NaOH in the stripping phase, cNaOH,S0 (10-2 and 1 kmol/m3), were selected as process factors. Their effects on the final values of IAA concentration in the feed phase (cIAA,Ff) and stripping solution (cIAA,Sf), extraction efficiency (EF), distribution coefficient (KD), and recovery efficiency (ER) were quantified using multiple regression equations. Regression coefficients were determined from experimental data, i.e., cIAA,Ff,ex=0.02-1×10-4 kmol/m3, cIAA,Sf,ex=0.22-2.58×10-3 kmol/m3, EF,ex=90.0-97.9%, KD,ex=9.0-46.6, and ER,ex=66.5-94.2%. It was found that cIAA,F0 had the most significant positive effect on cIAA,Ff and cIAA,Sf, whereas cNaOH,S0 had a major positive effect on EF, KD, and ER. A deterministic model based on mass transfer of IAA was developed and its parameters, i.e., mass transfer coefficient of IAA-L complex in the liquid membrane (0.08-1.15×10-6 m/s) and extraction constant (1033.9-1779.7 m3/kmol), were regressed from experimental data. The effect of cL,M0 on both parameters was significant.

Removal of Copper Ions from Aqueous Solution Using Liquid Surfactant Membrane Technique

Liquid Surfactant Membrane (LSM) as an alternative extraction technique shows many advantages without altering the chemistry of the oil process in terms of efficiency, cost effectiveness and fast demulsification post extraction. Copper (Cu) extraction from aqueous solution using Liquid Membrane (LM) technology is more efficient than the sludge-forming precipitation process and has to be disposed of in landfills. In this chapter, a liquid surfactant membrane (LSM) was developed that uses kerosene oil as LSM ‘s key diluent to extract copper ions as a carrier from the aqueous waste solution through di-(2-ethylhexyl) phosphoric acid (D2EHPA). This technique has several benefits, including extracting one-stage extracts. The LSM process was used to transport Cu (II) ions from the feed phase to the stripping phase, which was prepared, using H2SO4. For LSM process, various parameters have been studied such as carrier concentration, treat ratio (TR), agitating speed and initial feed concentration. After finding the optimum parameters, it was possible to extract Cu up to 95% from the aqueous feed phase in a single stage extraction.

Impact of Foods on The Gastrointestinal Microbiome of Obese Dogs During Weight Loss

Objectives The relationship between gut microbiome and obesity is known; this study focused on gut microbiome changes during weight loss in obese dogs fed three different foods Methods Control and two test foods formulated with a mean of 3153 kcals/kg SD ± 107.8. All foods were similar in their as fed protein (30.7% SD ± 0.73), carbohydrate (32.0% ±1.25) and fat (11.7% ±0.86) levels but differed in crude fiber (CF), total dietary fiber (TDF) and n-3FAs. Soluble: insoluble fiber (SF: IF) and n-3FAs: n-6FAs ratio were 0.13 and 0.07 in control and 0.27 and 0.62 in test foods. The study used 22 healthy adult dogs except their obese condition with a fat mass of >37% in a cross-over design. Control food was fed in pre-feed (28d) and washout period (28d) and two test foods were fed during treatment phases (phase 1 and 2, 56d each). All dogs were fed based on their body weight. DEXA was performed at the end of pre-feed, phase 1 and phase 2. Fecal samples were collected at the end of pre-feed, phase 1, washout, and phase 2. The study was approved by IACUC and dogs were allowed regular socializing. Fecal microbiome was analyzed by 16S rRNA amplicon sequencing using V3-V4 regions. Data analysis was performed using JMP v15.0. Variables with significance at P < 0.05 are reported. Results All foods resulted in weight loss. Microbiome analysis showed differences between dogs fed control and test foods, but no differences were observed between test foods. Bacteroidetes (B), Fusobacteria increased and Firmicutes (F) decreased in test compared to control food. Diversity, evenness and B: F ratio increased in test compared to control food. Genera, Bacteroides, Fusobacterium, Faecalibacterium, and Lachnospira increased and Clostridium, Blautia, Dorea, Peptococcus and Turicibacter decreased in test compared to control food. Regression analyses show Blautia and Clostridium have inverse (R2 0.10) and Fusobacterium has positive (R2 0.09) correlation with total lean mass. The intakes (g/kg BW0.75) of SF and n-3FAs show positive (R2 0.10 and 0.19) correlation to Fusobacterium and inverse (R2 0.12 and 0.10) correlation to total fat mass. Conclusions This study shows that gut microbiome of obese dogs significantly changes during weight loss. SF and n-3FAs levels have potential roles in weight loss with gut microbiome changes. Funding Sources Hill's Pet Nutrition, Inc.

Calixresorcin[4]arene-Mediated Transport of Pb(II) Ions Through Polymer Inclusion Membrane

A facilitated transport of Pb(II) through polymer inclusion membrane (PIM) containing 1,8,15,22-tetra(1-heptyl)-calixresorcin[4]arene and its tetra- and octasubstituted derivatives containing phosphoryl, thiophosphoryl or ester groups as an ion carrier was investigated. The efficiency of Pb(II) removal from aqueous nitrate solutions was considered as a function of the composition of membrane (effect of polymer, plasticizer, and carrier), feed (effect of initial metal concentration and presence of other metal ions) and stripping phases, and temperature of the process conducting. Two kinetic models were applied for the transport description. The highest Pb(II) ions removal efficiency was obtained for the membrane with tetrathiophosphorylated heptyl-calixresorcin[4]arene as an ion carrier. The activation energy value, found from Eyring plot to be equal 38.7 ± 1.3 kJ/mol, suggests that the transport process is controllable both by diffusion and chemical reaction. The competitive transport of Pb(II) over Zn(II), Cd(II), and Cr(III) ions across PIMs under the optimal conditions was also performed. It was found that the Cr(III) ions’ presence in the feed phase disturb effective re-extraction of Pb(II) ions from membrane to stripping phase. Better stability of PIM-type than SLM-type membrane was found.

Pengaruh Berbagai Parameter Ekstraksi dalam Pemisahan Unsur Tanah Jarang dengan Metode Emulsion Liquid Membrane (ELM)

<p>Unsur Tanah Jarang (UTJ) adalah 15 elemen kelompok lantanida, ditambah skandium dan itrium yang termasuk kelompok aktinida. UTJ memiliki banyak manfaat di berbagai bidang. Sifat fisik dan kimia yang mirip antar UTJ membuatnya sulit dipisahkan sehingga pemisahan UTJ menarik dipelajari dengan berbagai macam metode, salah satunya adalah dengan menggunakan <em>Emulsion Liquid Membrane </em>(ELM). ELM merupakan metode pemisahan yang dikembangkan dari ekstraksi pelarut terdiri dari tiga fase, yaitu fase eksternal (fase umpan) yang berisi UTJ yang akan dipisahkan, fase internal (fase pengupasan), dan fase membran. Fase membran berisi surfaktan sebagai penstabil dan ligan yang akan membentuk kompleks dengan UTJ pada antarmuka fase umpan dan membawanya berdifusi ke dalam fase pengupasan. ELM merupakan metode efektif untuk pemisahan karena tahap ekstraksi dan pengupasan (<em>stripping</em>) terjadi secara bersamaan dalam satu tahap dan fase membrannya dapat digunakan kembali. Pemisahan UTJ menggunakan metode ELM dengan berbagai ligan, seperti D2EHPA, Cyanex 572, P204, dan (RO)2P(O)OPh-COOH dipengaruhi oleh berbagai parameter, seperti konsentrasi ligan, pH fase umpan, waktu pengadukan ekstraksi, kecepatan pengadukan ekstraksi, rasio fase umpan, konsentrasi fase pengupasan, konsentrasi surfaktan, dan konsentrasi fase umpan. Parameter tersebut diseleksi untuk mendapatkan kondisi optimum sehingga meningkatkan efisiensi ekstraksi dan pengupasan yang berbeda.</p><p><strong>Effect of Various Parameters in Separation of Rare Earth Elements using the Emulsion Liquid Membrane (ELM) Method. </strong>Rare Earth Elements (REEs) are 15 elements of the lanthanide group, plus scandium and yttrium, which belong to the actinide group. REEs have many benefits in various fields. Similar physical and chemical properties between REEs make it difficult to separate, thus REEs separation is interesting to study by various methods, one of which is by using an emulsion liquid membrane (ELM). ELM is a method developed from solvent extraction consisting of three phases: the external phase (feed phase) which contains REEs to be collected, the internal phase (stripping phase), and the membrane phase. The membrane phase contains surfactants as stabilizers and ligands which will form complexes with REEs in the feed phase and are designed to diffuse into the stripping phase. ELM is an effective method to involve because extraction and stripping occur together in one glass and the membrane phase can be reused. Separation of REEs using the ELM method with various ligands, such as D2EHPA, Cyanex 572, P204, and (RO)2P(O)OPh-COOH influenced by various parameters, such as ligand concentration, feed phase pH, extraction stirring time, extraction stirring speed, feed phase ratio, stripping phase concentration, surfactant concentration, and feed phase concentration. These parameters are selected to obtain optimum conditions thereby increasing the efficiency of different extraction and stripping.</p><p> </p>

Optimization of donnan dialysis for alum recovery from potable water treatment residues

Treatment of effluent water to meet fresh water discharge limits is very essential. Aluminium sulphate (alum) is the most widely used coagulant during the pre-treatment process, however, it generates a large amount of residue. Subsequent discharge of these residues from potable water treatment plants (PWTPs) to landfill sites and river bodies, without treatment, poses a great threat to the ecosystem and human health. In essence, the rising concern of managing residues, associated with the disposal cost, toxicity and stringent legislation, calls for more robust and effective technologies. In response, this study comes in handy owing to the green chemistry benefits of aluminium recovery from PWTPs for reuse. Primary recovery methods include acid treatment and alkalization. Although these two recovery processes ensue a minimum of 60% recovery, organics and heavy metals solubilize during the process. Donnan dialysis as a separation, recovery and concentrating technology is investigated in this project. The aims and objectives were to optimize the recovery of aluminium using Donnan dialysis with respect to phase conditions, to evaluate the inhibition effect of selected metals on aluminium transport and finally, to establish the organic transport in Donnan dialysis. Using a statistical approach, the feed phase conditions such as feed flowrate (0.64-2.21 mL/s), feed concentration (100-3300 mg/L), and pH (1.3-3.7) were considered against sweep phase conditions of acid concentration (0.25-1 N) and flowrate (0.64-2.21 mL/s). The response surface methodology’s face-centered central composite design (FC-CCD) statistical method was adapted for the selection of influential factors and establishing the relationship between selected conditions. The FC-CCD used had three levels and six center points for analysis. The effect of Ca, Mg, Mn, Fe, Cu, Zn and Pb on Al permeation through the Nafion 117 membrane was studied at constant flow and concentration conditions. Once the effects in the binary inhibition study were completed, aluminium recovery from a residue obtained from a local PWTP was conducted. Simultaneously, the rejection of organics by the membrane was also assessed during the aluminium recovery process. Preliminary experiment validation experiments showed a high deviation of ±6.4 mg/L at the feed phase, 7.33% deviation at the sweep phase and mass balance closure greater than 95%. Furthermore, study on the water transport across the membrane was directly proportional to the acid concentration. Comparing HCl and H2SO4, HCl had a lower Van’t Hoff factor, hence, was used in proceeding experiments. A one factor at a time experiment to determine the final range of feed concentration to use showed that a maximum of 2000 mg/L was required to meet a 50% recovery target. The FC-CCD experiment showed that the ascending order of the effects of factors was sweep flowrate < feed flowrate < sweep concentration < feed concentration. The sweep flowrate had a negative influence on aluminium permeation and was statistically insignificant (p > 0.05). Quadratic and predictive models developed at different time intervals were statistically significant at a 95% confidence level. Also, a high recovery of 94% and high concentrating effect at the sweep phase was 1.65 in the 2:1 feed to sweep phase volume experiment. Analysis of FC-CCD combinative study of feed concentration, pH of feed phase and feed flowrate showed that a high feed concentration (> 1000 mg/L) at a high pH (> 2.5) will yield an Al-recovery > 60%. At a 95% confidence level, the statistical analysis showed that the pH was the most significant factor. The interacting factors for the statistically significant model was feed concentration-feed flowrate and feed concentration-pH. The one-on-one inhibitive study at equal phase flowrates and feed concentration revealed that Fe gave the highest inhibition while the least transport across the Nafion 117 membrane was Mn2+. In descending order, Fe2+ > Ca2+ > Zn2+ > Mg2+ > Cu2+ . The rejection of organics is limited to 24- 32 hours where a maximum of 98% rejection was achieved under the synthetized solution and acid digested residue runs. In conclusion, Donnan dialysis by RSM has proven to be feasible for the recovery of aluminium from potable water treatment residue. Also, the FC-CCD adapted from the RSM is seen to be very promising, economical and a reliable alternative statistical tool to determine the most influential factor and predict and obtain the optimal operation conditions for a system. Therefore, there are economic, sustainable and research prospects of DD coupled with RSM towards recovery of metal salts and heavy metals from PWTP residues in large scale implementation.

Removal of Acetaminophen Residues from Wastewater by Bulk Liquid Membrane Process

The removal of Anit-Inflammatory drugs, namely; Acetaminophen (ACTP), from wastewater by bulk liquid membrane (BLM) process using Aliquat 336 (QCl) as a carrier was investigated. The effects of several parameters on the extraction efficiency were studied in this research, such as the initial feed phase concentration (10-50) ppm of ACTP, stripping phase (NaCl) concentration (0.3,0.5,0.7 M), temperature (30-50oC), the volume ratio of feed phase to membrane phase (200-400ml/80ml), agitation speed of the feed phase (75-125 rpm), membrane stirring speed (0, 100, 150 rpm), carrier concentration (1, 5, 9 wt%), the pH of feed (2, 4, 6, 8, 10), and solvent type (CCl4 and n-Heptane). The study shows that high extraction efficiency for ACTP of about 97% was achieved by a bulk liquid membrane at 50 ppm initial concentration of feed; stirring speed of feed phase 130 rpm; stirring speed of membrane phase 100rpm; 0.5 M NaCl concentration; carrier concentration 1wt%; volume ratio of 200ml feed:80ml membrane; feed pH of ACTP is 6, and 50˚C. The transport kinetics was evaluated using a kinetic model with two consecutive first-order irreversible reactions. The kinetics of (ACTP) transport by bulk liquid membrane was investigated at the best experimental conditions. The activation energy values of the extraction and stripping processes were 1.733 and 1.826 kJ.mol−1. The activation energy confirms that the transport process from solutions is controlled by diffusion.

Transport of Au(III) from HCl Medium across a Liquid Membrane Using R3NH+Cl−/Toluene Immobilized on a Microporous Hydrophobic Support: Optimization and Modelling

By the use of the tertiary amine A327 and 1 M HCl solution as precursors, the ionic liquid A327H+Cl− was generated and used to investigate its performance in the transport of Au(III) from hydrochloric acid medium. The influence of the stirring speed (600–1800 min−1), ionic liquid concentration (1.25–50% v/v) in the membrane phase, and gold concentration (0.01–0.15 g/L) in the feed phase on metal transport have been investigated. An equation which included both equilibrium and kinetics parameters was derived, and the membrane diffusional resistance (Δm) and feed phase diffusional resistance (Δf) was estimated as 9.5 × 106 s/cm and 307 s/cm, respectively. At carrier concentrations in the 5–50% v/v range and gold concentrations in the 0.01–0.15 g/L range, metal transport is controlled by diffusion of metal species through the feed boundary layer, whereas at the lowest carrier concentrations, membrane diffusion is predominant. From the receiving solutions, gold can be recovered as gold nanoparticles.