Emulsion ionic liquid membrane using edible paraffin oil for lead removal from aqueous solutions

Removal of lead ions using OA-Fe3O4 magnetic nanoparticles-based pickering emulsion liquid membrane: process optimization using box-behnken response surface methodology

The purpose of this study is to explore the pickering emulsion liquid membrane (PELM) performance for removing divalent lead ions (Pb II) from aqueous solution. In the present work, the membrane phase was prepared by dissolving methyltrioctylammonium chloride (Aliquat 336) with Mahua oil and adding oleic acid coated-ferrosoferric oxide (OA-Fe₃O₄) as magnetic nanoparticles. Experimental investigation on percentage removal of lead ions was carried out by studying the influencing process parameters such as pH, agitation speed, stripping concentration, initial feed concentration, surfactant concentration, treat ratio, M/S ratio and carrier concentration. The optimum condition to remove 98.52% of lead ions from the feed solutions has achieved at a stripping phase concentration of 0.3 M, treat ratio of 3, agitation speed of 300 rpm, initial feed concentration of 10 ppm and stabilizer concentration of 2 wt%. The experimental results were validated using box-behnken response surface methodology. The extraction ability of OA-Fe₃O₄ magnetic nanoparticles-based PELM has been evaluated using statistical optimization of all the affecting process factors using the design of the experiments.

Reuse of waste cooking oil (WCO) as diluent in green emulsion liquid membrane (GELM) for zinc extraction

Zinc (Zn) was identified as one of the most toxic heavy metals and often found contaminating the water sources as a result of inefficient treatment of industrial effluent. A green emulsion liquid membrane (GELM) was proposed in this study as a method to minimize the concentration of Zn ions in an aqueous solution. Instead of the common petroleum-based diluent, the emulsion is reformulated with untreated waste cooking oil (WCO) collected from the food industry as a sustainable and cheaper diluent. It also includes Bis(2-ethylhexyl) phosphate (D2EHPA) as a carrier, Span 80 as a surfactant, sulfuric acid (H2SO4) as an internal phase, and ZnSO4 solution as an external phase. Such formulation requires a thorough understanding of the oil characteristics as well as the interaction of the components in the membrane phase. The compatibility of WCO and D2EHPA, as well as the external phase pH, was confirmed via a liquid-liquid extraction (LLE) method. To obtain the best operating conditions for Zn extraction using GELM, the extraction time and speed, carrier, surfactant and internal phase concentrations, and W/O ratio were varied. 95.17% of Zn ions were removed under the following conditions; 0.001 M of H2SO4 in external phase, 700 rpm extraction speed for 10 min, 8 wt% of carrier and 4 wt% of surfactant concentrations, 1:4 of W/O ratio, and 1 M of internal phase concentration.

Possibility of New Active Substrates (ASs) to Be Used to Prevent the Migration of Heavy Metals to the Soil and Water Environments

This paper aims to propose an alternative to the known permeable reactive barriers (PRBs). PRB is one of the methods, which is a reactive barrier placed below the ground, to clean up contaminated groundwater. New polymer active substrates (ASs) were used to prevent soil contamination by toxic heavy metals. The active substrates consisted of a mixture of poly(vinyl chloride), Aliquat 336, and bis(2-ethylhexyl)adipate, which was applied to the skeleton material (fiberglass or textile). Aliquat 336 was used as a binding agent for metal ions (Cr(VI), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II)). In contrast with the PRBs, the ASs (from AS-1 to AS-5) were obtained in a simple way using the pouring method. The obtained ASs could be recycled and reused. The active substrates were used for the binding of various metal ions from aqueous solutions and the examined soil. It was found that the active substrate AS-1 decreased the concentrations of nickel, cadmium, and lead by more than 50% and that of chromium by more than 90% in the aqueous solution. High sorption efficiency for chromium and zinc metals (81% and 66%) with the use of AS-2 was also found, owing to which the migration of metals from soil to water can be limited. In the soil environment, active substrate AS-5 with the addition of a plasticizer showed the greatest effectiveness. This solution resulted in a reduction in each tested metal ion of at least 50%, and reductions in cadmium, lead, and copper of over 70%.

Reuse of Waste Cooking Oil (WCO) as Diluent in Green Emulsion Liquid Membrane (GELM) for Zinc Extraction.. [DOI: 10.21203/rs.3.rs-1251988/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Zinc (Zn) was identified as one of the most toxic heavy metals and often found contaminating the water sources as a result of inefficient treatment of industrial effluent. A Green Emulsion Liquid Membrane (GELM) was proposed in this study as a method to minimize the concentration of Zn ions in an aqueous solution. Instead of the common petroleum-based diluent, the emulsion is reformulated with untreated waste cooking oil (WCO) collected from the food industry as a sustainable and cheaper diluent. It also includes Bis(2-ethylhexyl) phosphate (D2EHPA) as carrier, Span 80 as surfactant, sulfuric acid (H2SO4) as internal phase and ZnSO4 solution as external phase. Such formulation requires a thorough understanding of the oil characteristics as well as the interaction of the components in the membrane phase. The compatibility of WCO and D2EHPA, as well as the external phase pH was confirmed via liquid-liquid extraction (LLE) method. To obtain the best operating conditions for Zn extraction using GELM, the extraction time and speed, carrier, surfactant and internal phase concentrations, and W/O ratio were varied. 95.17% of Zn ions were removed under the following conditions; 0.001M of H2SO4 in external phase, 700 rpm extraction speed for 10 minutes, 8 wt% of carrier and 4 wt% of surfactant concentrations, 1:4 of W/O ratio and 1 M of internal phase concentration.

A polyurethane foam membrane filled with double cross-linked chitosan/carboxymethyl cellulose gel and decorated with ZSM-5 nano zeolite: Simultaneous dye removal

A novel bio-based polyurethane foam was fabricated using double cross-linked chitosan/carboxymethyl cellulose gel, filled with ZSM-5 nano zeolite, and hot-pressed into the membrane. The prepared foam membrane was characterized using FESEM, FTIR, BET, TGA, and pH_ZPC analyses and then used for continuous dye removal. The results modification of polyurethane foam with chitosan/carboxymethyl cellulose gel and ZSM-5 nano zeolite would increase the retention ability of positive cationic methylene blue. Also, the foam could simultaneously remove methyl orange, eriochrome black T, and methylene blue from the binary and trinary solutions but could effectively be used to selectively removal methylene blue. In addition, the dye removal ability at the breakthrough was enhanced with decreasing flow rate, and increasing bed height, pH, initial dye concentration, and nano zeolite content in the foam. To describe the breakthrough curves different models were utilized which best fits were obtained with Modified Dose-Response as compared to Thomas, Adams & Bohart, Yoon-Nelson, and Wolborska models.

Conversion of waste cooking oil into value-added emulsion liquid membrane for enhanced extraction of lead: Performance evaluation and optimization

This research study investigated the synthesis of environmentally benign green emulsion liquid membrane (GELM) employing waste cooking oil (WCO) as diluent. The emulsion was prepared using D2EHPA as the carrier, Span 80 as surfactant, and sulphuric acid as internal/stripping agent. The influence of nine operating variables namely, Span 80 concentration, D2EHPA concentration, shaking time, shaking speed, pH of the feed, treat ratio (TR), H₂SO₄ concentration, lead concentration in feed, and volume ratio of organic phase to aqueous phase (O/A) on the performance of lead extraction was studied. Plackett Burman design (PBD), was employed for the screening of variables. The Pareto analysis shows that six variables were the most significant variables at the confidence level of 95%. The selected variables were then screened applying Box-Behnken design (BBD). The optimum values of the variables were: D2EHPA concentration - 4.6 (v/v%), Span 80 concentration - 2.14 (v/v%), pH of the feed - 4.4, internal phase (H₂SO₄) concentration - 2 M, initial lead concentration - 173 ppm, phase ratio (O/A) - 1.3. At these optimum conditions, a maximum lead extraction of 97.39% was obtained. The mechanism for the extraction of lead was analyzed. Reuse and recycling of membrane phase show that the GELM can be recycled for 7 cycles without reduction in lead extraction efficiency. Kinetic analysis of lead extraction was performed using zero, first, and second-order model at optimum condition. The experimental data fitted well with first-order (R² - 0.9653). Thermodynamic studies indicated that the extraction procedure is endothermic, spontaneous in nature.

Emulsion liquid membrane modeling for chromium removal from electroplating wastewater using TOMAC as a carrier

Hexavalent chromium, emanating primarily from the electroplating industries, can be reduced to the less toxic trivalent variety by several methods, including emulsion liquid membrane (ELM). In this work, studies on the continuous removal of chromium from authentic electroplating wastewater by ELM are reported. The effects of treat ratio, external feed phase, and stripping agent concentration were examined. A mathematical boundary breakage model was used to study the extraction efficiency of chromium through the ELM process. The model representing the prediction of ELM extraction performance for chromium was validated through the comparison between the simulation and experimental results. The result showed the simulation model is found to be in good agreement with the experimental result. Almost 100% of 40 ppm chromium in the external feed phase was extracted within 3 to 5 min using 0.022 M TOMAC as extractant, 1.0 M acidic thiourea in the internal phase, and 1 to 5 of treat ratio. PRACTITIONER POINTS: Hexavalent chromium, emanating primarily from electroplating industries, can be reduced to the less toxic trivalent using ELM process. The developed method was tested for its applicability with predominant species of Cr₂ O₇ ^2- in real rinse electroplating wastewater. The extraction efficiency (%) of Cr (VI) was almost 100% for 40 ppm Cr in the external feed phase within 3 to 5 min. The result showed the simulation model is found to be in good agreement with the experimental result.